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Sample records for chisels

  1. Chiseled Gold Ornament

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    According to some archaeological discoveries, people began to use gold to make ornaments during the Shang Dynasty, more than 3,000 years ago. This partfcular piece of chiseled gold ornament was unearthed in 1957 from the Ming Dynasty tomb of Wang Gui at You’anmen, Beijing. Wang Gui was a head of the Imperial Bodyguard in the Ming Dynasty. His eldest daughter was an imperial concubine of the Emperor Cheng Hua. Consequently, his family held a prominent position at the time. The gold ornament, 50.5 centimeters in length and 295 grams in weight, is composed of two parts. The upper part is shaped like lotus leaves, with fine double lines as the vein. To indicate auspiciousness, a pair of mandarin ducks with lotus flowers in their months sit on either side of the thick leaves. Seven long gold chains measuring 21 centimeters in length link the

  2. Temporary effect of chiseling on the compaction of a Rhodic Hapludox under no-tillage

    Directory of Open Access Journals (Sweden)

    Sâmala Glícia Carneiro Silva

    2012-04-01

    Full Text Available Mechanical chiseling has been used to alleviate the effects of compaction in soils under no-tillage (NT. However, its effect on the soil physical properties does not seem to have a defined duration period. The purpose of this study was to evaluate the behavior of the bulk density (BD and degree of compaction (DC at different soil depths, after chiseling in no-tillage, for one year. The experiment was performed in Ponta Grossa, Paraná State, Brazil, using an Oxisol (Rhodic Hapludox. Bulk density and DC were previously measured in an area under NT for 16 years, then immediately after chiseling (CHI in May 2009, six months after chiseling (CHI6M in October 2009 and one year after chiseling (CHI12M in May 2010. In the layers 0.0-0.10, 0.10-0.20 and 0.20-0.30 m, there was a significant BD reduction CHI and a marked increase CHI6M. The BD values measured CHI12M were similar to those before tillage. Chiseling reduced the DC in the layers 0.0-0.10 m and 0.10-0.20 m, but returned to the initial values one year later. During the evaluation periods CHI, CHI6M and CHI12M, the BD increased in the layer 0.30-0.40 m, compared with NT. The highest DC values were observed six months after chiseling; nevertheless the structural recovery of the soil was considerable, possibly due to the high degree of soil resilience and the influence of the wetting and drying cycles detected in the study period. The chiseling effects, evaluated by BD and DC, lasted less than one year, i.e., the beneficial short-term effects of chiseling on the reduction of the surface BD increased the risk of compaction in deeper soil layers.

  3. Direct observation of a long-lived single-atom catalyst chiseling atomic structures in graphene.

    Science.gov (United States)

    Wang, Wei Li; Santos, Elton J G; Jiang, Bin; Cubuk, Ekin Dogus; Ophus, Colin; Centeno, Alba; Pesquera, Amaia; Zurutuza, Amaia; Ciston, Jim; Westervelt, Robert; Kaxiras, Efthimios

    2014-02-12

    Fabricating stable functional devices at the atomic scale is an ultimate goal of nanotechnology. In biological processes, such high-precision operations are accomplished by enzymes. A counterpart molecular catalyst that binds to a solid-state substrate would be highly desirable. Here, we report the direct observation of single Si adatoms catalyzing the dissociation of carbon atoms from graphene in an aberration-corrected high-resolution transmission electron microscope (HRTEM). The single Si atom provides a catalytic wedge for energetic electrons to chisel off the graphene lattice, atom by atom, while the Si atom itself is not consumed. The products of the chiseling process are atomic-scale features including graphene pores and clean edges. Our experimental observations and first-principles calculations demonstrated the dynamics, stability, and selectivity of such a single-atom chisel, which opens up the possibility of fabricating certain stable molecular devices by precise modification of materials at the atomic scale.

  4. CALCULATION OF MAGNETIC RESISTANCE OF A CHISEL WORKING ORGAN FOR FIBREWISE SUBSURFACE TILLAGE

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    Bozhko I. V.

    2014-04-01

    Full Text Available The article presents a calculation of traction resistance chisel working organ for layered subsurface soil treatment and proposed the construction of a working body for subsurface tillage with an elliptical element. We have also included a comparative analysis of traction resistance of workers to the waterline and moldboard tillage

  5. Least limiting water range in soil under crop rotations and chiseling

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    Juliano Carlos Calonego

    2011-06-01

    Full Text Available Soil water availability to plants is affected by soil compaction and other variables. The Least Limiting Water Range (LLWR comprises soil physical variables affecting root growth and soil water availability, and can be managed by either mechanical or biological methods. There is evidence that effects of crop rotations could last longer than chiseling, so the objective of this study was to assess the effect of soil chiseling or growing cover crops under no-till (NT on the LLWR. Crop rotations involving triticale (X Triticosecale and sunflower (Helianthus annuus in the fall-winter associated with millet (Pennisetum glaucum, sorghum (Sorghum bicolor and sunn hemp (Crotalaria juncea as cover crops preceding soybean (Glycine max were repeated for three consecutive years. In the treatment with chiseling (performed only in the first year, the area was left fallow between the fall-winter and summer crops. The experiment was carried out in Botucatu, São Paulo State, Brazil, from 2003 to 2006 on a Typic Rhodudalf. The LLWR was determined in soil samples taken from the layers 0-20 cm and 20- 40 cm, after chemical desiccation of the cover crops in December of the first and third year of the experiment. Chiseling decreases soil bulk density in the 0-20 cm soil layer, increasing the LLWR magnitude by lowering the soil water content at which penetration resistance reaches 2.0 MPa; this effect is present up to the third year after chiseling and can reach to a depth of 0.40 m. Crop rotations involving sunflower + sunn hemp, triticale + millet and triticale + sunn hemp for three years prevented soil bulk density from exceeding the critical soil bulk density in the 0- 0.20 m layer. This effect was observed to a depth of 0.40 m after three years of chiseling under crop rotations involving forage sorghum. Hence, chiseling and some crop rotations under no tillage are effective in increasing soil quality assessed by the LLWR.

  6. DESIGN FEATURES OF THE NEW CHISEL COMBINED AND CALCULATION NEEDS OF THE ENGINE POWER AT HIS WORK

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    Maslov G. G.

    2015-05-01

    Full Text Available The article presents technologies and design features of the proposed chisel combined unit, combining in a single pass over the field 3 operations: deep loosening, crumbling additional topsoil and alignment, fertilizing. Design features of such a subsoiller as the basis of the unit include a chisel on each rack, fixed at an angle of 15-25 degrees to the horizontal and lessons along the center line of the rack feet, and flat cutting fun-leveling, consisting of two coaxially bred drums equipped with ripper teeth securely fastened according to our patents and placed in 5-9 rows on the surface of the drums on the helix, with rows of teeth on both drums have the opposite direction. The teeth of the first drum are long by 5-9 cm than the second, the clearance between the teeth of the first and second drum does not exceed 1.5 cm, and the ends of the teeth between the first reel and the cylindrical surface of the second - 1 cm. Front legs each provided with a divider soil laid down by its center and related to the lower of its parts - the bit. The first reel is mounted to 5 cm clearance between it and the cylindrical surface of the soil, which improves process reliability. We have got analytical dependences of the required power for the engine of the tractor unit with the proposed change of the working speed and width at the optimum utilization traction tractor plowing 0.9. We have justified a preferred brand of domestic and foreign tractors for this purpose

  7. Derivation of soil screening thresholds to protect chisel-toothed kangaroo rat from uranium mine waste in northern Arizona

    Science.gov (United States)

    Hinck, Jo E.; Linder, Greg L.; Otton, James K.; Finger, Susan E.; Little, Edward E.; Tillitt, Donald E.

    2013-01-01

    Chemical data from soil and weathered waste material samples collected from five uranium mines north of the Grand Canyon (three reclaimed, one mined but not reclaimed, and one never mined) were used in a screening-level risk analysis for the Arizona chisel-toothed kangaroo rat (Dipodomys microps leucotis); risks from radiation exposure were not evaluated. Dietary toxicity reference values were used to estimate soil-screening thresholds presenting risk to kangaroo rats. Sensitivity analyses indicated that body weight critically affected outcomes of exposed-dose calculations; juvenile kangaroo rats were more sensitive to the inorganic constituent toxicities than adult kangaroo rats. Species-specific soil-screening thresholds were derived for arsenic (137 mg/kg), cadmium (16 mg/kg), copper (1,461 mg/kg), lead (1,143 mg/kg), nickel (771 mg/kg), thallium (1.3 mg/kg), uranium (1,513 mg/kg), and zinc (731 mg/kg) using toxicity reference values that incorporate expected chronic field exposures. Inorganic contaminants in soils within and near the mine areas generally posed minimal risk to kangaroo rats. Most exceedances of soil thresholds were for arsenic and thallium and were associated with weathered mine wastes.

  8. Effect of Plowing Depth of Tillage and Forward Speed on the Performance of a Medium Size Chisel Plow Operating in a Sandy Soil

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    S. A. Al-Suhaibani

    2010-01-01

    Full Text Available Problem statement: Tillage is a process of creating a desirable soil condition for seed germination and growth. The tillage of soil is considered to be one of the biggest farm operations as the tillage operation requires the most energy on the farm. Chisel plow is widely used by farmers as a primary tillage tool. Performance data for chisel plow operation is essential in order to reduce the cost of tillage operation. Approach: Field experiments were conducted using a fully instrumented MS 3090 tractor to measure the draft of a heavy duty chisel plow in a sandy soil over wide ranges of plowing depths and forward speeds. The data were measured and recorded using an instrumentation system and data logger. Results: The effects of plowing depth and forward speeds on draft, unit draft, vertical specific draft, horizontal specific draft and coefficient of pull were evaluated. The results indicated that increasing the plowing depth and/or the forward speed increased the draft, unit draft and vertical specific draft. Also, increasing the plowing depth increased the horizontal specific draft and the coefficient of pull, while increasing the forward speed decreased the horizontal specific draft and the coefficient of pull. Conclusion: About 16.6% of the draft force was directed towards cutting the soil and 83.4% was consumed in pulverization of soil particles. The values of the vertical specific draft were much higher than those of the horizontal specific draft for all plowing depths and forward speeds. The plowing depth had more pronounced effect on the draft, unit draft, specific draft and coefficient of pull than the forward speed. The optimum forward speed was 1.75 m sec-1. The recommended plowing depth should be based on the type of crop (depth of the root system.

  9. ChISELS 1.0: theory and user manual :a theoretical modeler of deposition and etch processes in microsystems fabrication.

    Energy Technology Data Exchange (ETDEWEB)

    Plimpton, Steven James; Schmidt, Rodney Cannon; Ho, Pauline; Musson, Lawrence Cale

    2006-09-01

    Chemically Induced Surface Evolution with Level-Sets--ChISELS--is a parallel code for modeling 2D and 3D material depositions and etches at feature scales on patterned wafers at low pressures. Designed for efficient use on a variety of computer architectures ranging from single-processor workstations to advanced massively parallel computers running MPI, ChISELS is a platform on which to build and improve upon previous feature-scale modeling tools while taking advantage of the most recent advances in load balancing and scalable solution algorithms. Evolving interfaces are represented using the level-set method and the evolution equations time integrated using a Semi-Lagrangian approach [1]. The computational meshes used are quad-trees (2D) and oct-trees (3D), constructed such that grid refinement is localized to regions near the surface interfaces. As the interface evolves, the mesh is dynamically reconstructed as needed for the grid to remain fine only around the interface. For parallel computation, a domain decomposition scheme with dynamic load balancing is used to distribute the computational work across processors. A ballistic transport model is employed to solve for the fluxes incident on each of the surface elements. Surface chemistry is computed by either coupling to the CHEMKIN software [2] or by providing user defined subroutines. This report describes the theoretical underpinnings, methods, and practical use instruction of the ChISELS 1.0 computer code.

  10. Propriedades físico-hídricas do solo e demanda energética de haste escarificadora em Argissolo compactado Soil physicohydric properties and chisel energy demand in a compacted Alfisol

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    Marcelo Ivan Mentges

    2010-03-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da compactação nos atributos físico-hídricos do solo e na demanda energética da haste escarificadora, além de avaliar as propriedades físico-hídricas abaixo da profundidade de trabalho da haste. O trabalho foi conduzido em Argissolo Vermelho-Amarelo de textura francoarenosa, com os seguintes tratamentos: plantio direto por 13 anos; plantio direto por 13 anos em solo escarificado; plantio direto em solo com compactação adicional; e plantio direto em solo com compactação adicional escarificado. A compactação, ao longo da profundidade escarificada, foi verificada por meio dos dados de esforço de tração associados à haste escarificadora, obtidos com auxílio de um anel octogonal ligado a um módulo de aquisição de dados. Foram determinados densidade, porosidade total, macroporosidade, microporosidade, condutividade hidráulica saturada e resistência mecânica do solo à penetração. A compactação elevou a densidade e a resistência mecânica à penetração do solo, reduziu a porosidade total e a macroporosidade, porém sem causar efeitos significativos na microporosidade. A compactação aumentou a demanda energética da haste escarificadora em 21,64%, o que elevou os valores médios de esforço de tração de 5,33 para 6,35 kN. A escarificação não elevou o estado de compactação do solo abaixo da profundidade de trabalho da haste escarificadora, em solo francoarenoso.The objective of this work was to evaluate the soil compaction effect on its physicohydric properties and on chisel energy demand, as well as to quantify the behavior of these properties below the chisel working depth. The experiment was carried out in a sandy loam Alfisol, with the following treatments: no-tillage for 13 years; no-tillage for 13 years and chiseling; no-tillage with additional compaction; and no-tillage with additional compaction and chiseling. Compaction along the chiseling depth was verified

  11. Impacts of Grinding Allowance on Relief Angle and Chisel Edge Angle of Twist Drills%磨削余量对麻花钻后角和横刃斜角的影响

    Institute of Scientific and Technical Information of China (English)

    戴俊平; 关文魁; 郭辉

    2011-01-01

    Most of based-cone-grinding-method grinding theories supposed that before and after grinding, the position of main cutting edge on twist drill is unchanged, and the impacts of grinding allowance on grinding parameters are neglected. But in the actual machining process, even if grinding parameters are selected reasonably, the both relief angle and chisel edge angle can be beyond the scope of optimal cutting parameter. In this paper, the cone surface equation taking into account the grinding admittance was presented, the calculation formulas of relief angle and chisel edge angle were deduced, and the impacts of grinding allowance on relief angle and chisel edge angle were analyzed. It is found that the grinding allowance is the main reason lead to oversized relief angle and chisel edge angle.%基于锥面刃磨法的刃磨理论大多假设,麻花钻刃磨前后主切削刃在砂轮上的位置保持不变,忽略了磨削余量对刃磨参数的影响.而在实际加工中,即使刃磨参数选择合理,重刃磨的麻花钻后角和横刃斜角均可能不在优化加工参数范围之内.本文给出了考虑磨削余量的锥面方程,推导出后角和横刃斜角的计算公式,分析了磨削余量对后角和横刃斜角的影响,发现磨削余量是导致后角和横刃斜角偏大的主要原因.

  12. Estabilidade de agregados do solo após manejo com rotações de culturas e escarificação Soil aggregate stability after management with crop rotation and chiseling

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    Juliano Carlos Calonego

    2008-08-01

    Full Text Available O objetivo desse trabalho foi avaliar, em solo compactado, a estabilidade dos agregados influenciada pelo cultivo de espécies de cobertura em esquema de rotações de culturas, em sistema de semeadura direta, mediante o efeito da escarificação mecânica. As rotações de culturas repetidas por três anos consecutivos envolveram o cultivo de triticale e girassol, no outono-inverno, associados ao cultivo de milheto, de sorgo forrageiro e de Crotalária júncea como plantas de cobertura, antecedendo o da soja (cultura de verão. No tratamento envolvendo a escarificação mecânica, a área permaneceu em pousio entre os cultivos de outono-inverno e de verão. O experimento foi realizado na Fazenda Experimental Lageado (Botucatu-SP, nos anos agrícolas de 2003/2004, 2004/2005 e 2005/2006. O delineamento experimental foi o de blocos ao acaso, com quatro repetições, em esquema de parcelas subdivididas. As amostras para a análise da estabilidade de agregados foram coletadas nas profundidades de 0 a 0,05 m e de 0,05 a 0,10 m após o manejo das plantas de cobertura em dezembro de 2003 e de 2005. Logo no primeiro ano de instalação do experimento, o cultivo de triticale resultou em maior porcentagem de agregados com mais de 2 mm, maior DMG e maior DMP na camada de 0 a 5 cm, além de maior DMP na camada de 0,05 a 0,10 m. Já a escarificação do solo e a ausência do cultivo de plantas de cobertura proporcionaram menor porcentagem de agregados maiores que 2 mm e menor DMP na camada de 0,05 a 0,10 m. A estabilidade dos agregados foi influenciada pela rotação de culturas, sendo maior na camada de 0 a 0,05 m e de 0,05 a 0,10 m quando o triticale foi introduzido como espécie de outono-inverno.The objective of this study was to compare, in compacted soil condition, the aggregate stability after different crops rotations under no-tillage system and chiseling. The following crop rotations were repeated for three consecutive years under no

  13. Painless minimally invasive surgery versus chisel osteotomy in the extraction of impacted mandibular third molars%无痛微创法与凿骨劈冠法拔除下颌阻生智齿的临床观察

    Institute of Scientific and Technical Information of China (English)

    李然; 唐小剑; 杨震; 朱正宏

    2012-01-01

    目的 观察无痛微创法和凿骨劈冠法拔除下颌阻生智齿的临床疗效.方法 306颗下颌阻生智齿随机分成2组,分别采用无痛微创法(实验组)和凿骨劈冠法(对照组)拔除患牙,记录2组平均拔除时间、术后肿胀、疼痛、张口受限、颞颌关节痛、干槽症等并发症发生情况及对拔牙的畏惧感.结果 实验组与对照组相比,平均拔除时间明显缩短(P<0.01);术后疼痛、肿胀、张口受限、颞颌关节痛、干槽症等并发症发生率较对照组明显降低(P<0.01);术前畏惧在术后的消失率和术前不畏惧在术后出现的畏惧率,均表明实验组优于对照组(P<0.001).结论 随着社会-心理-生物医学模式的不断完善,拔牙手术正由传统的凿骨劈冠法向着无痛、微创、安全、规范、舒适、愉悦等人性化方向发展.%Objective To compare the clinical effects of minimally invasive surgery ( MIS) with those of traditional chisel osteotomy in the extraction of impacted mandibular third molars. Methods We extracted 306 impacted mandibular third molars by MIS (experimental group) and traditional chisel osteotomy (control group) , respectively, and compared the two groups in the operation time, patients'fear of tooth extraction and postoperative complications, such as swelling, pain, limitation of mouth opening, sore temporoman-dibular joint and dry socket. Results Compared with the controls, the experimental group showed significantly shorter operation time, lower rates of pain, swelling, limitation of mouth opening, sore temporomandibular joint, dry socket, and less fear of tooth extraction (P <0. 01). Conclusions MIS is evidently superior over chisel osteotomy in the extraction of impacted mandibular third molars. With the development of the model of socio-psycho-bio-medicine, tooth extraction is assuming more humanized characteristics as pain-lessness, invasiveness, safety, comfort and normalization.

  14. Minimally invasive surgery versus chisel osteotomy in the extraction of impacted mandibular third molars%微创法与锤凿法拔除下颌阻生智齿的临床研究

    Institute of Scientific and Technical Information of China (English)

    肖平; 卢向阳; 余尚龙; 吕美玲; 陈芝

    2012-01-01

    Objective: To assess the application value of minimally invasive surgery (MIS) in the extraction of impacted mandibular third molars. Methods: A total of 342 patients with impacted mandibular third molars to be extracted were randomly assigned to an experimental group and a control group to be performed tooth extraction by MIS and traditional chisel osteotomy, respectively. We compared the two groups in the operation time and postoperative complications, such as swelling, pain, limitation of mouth opening, sore temporomandibular joint and dry socket. Results: Compared with the controls, the experimental group showed significantly shorter operation time (P<0.001), lower rates of postoperative pain, swelling, limitation of mouth opening, dry socket and sore temporomandibular joint (P<0.005). Conclusion: MIS, with its evident superiority to chisel osteotomy, would gradually take place of the latter in the extraction of impacted mandibular third molars.%目的:评估微创拔牙技术在阻生牙拔除术中的应用价值.方法:选择342例需拔除下颌阻生智齿患者,随机分成2组,分别采用微创法和锤凿法拔除患牙,记录两种方法平均拔除时间、术后肿胀、疼痛、张口受限、颞颌关节痛、干槽症等并发症发生情况.结果:实验组与对照组相比,平均拔除时间明显缩短(P<0.001);术后疼痛、肿胀、张口受限、干槽症、颞颌关节痛等并发症发生率较对照组明显降低(P<0.005).结论:随着微创医学的发展及新型拔牙器械的推出,微创拔牙理念和技术将逐渐取代传统的锤凿法.

  15. 高速涡轮气钻法与凿骨劈冠法在拔除下颌水平埋伏阻生智齿中的对比研究%Comparison of High-speed Air Turbine and Traditional Chisel Technique on Extracting Impacted Mandible Third Molars

    Institute of Scientific and Technical Information of China (English)

    林静; 卢保全; 陈永锋; 王英

    2013-01-01

    Objective:To compare the clinical effects of high -speed air turbine drill and traditional chisel on removal of impacted mandible third molars .Methods:The clinical datas of the patients with 120 lower impacted mandible third molar were retrospectively analyzed .In witch high-speed air drill group(60) and chisel group(60)to be performed tooth extraction by high -speed air drill and traditional chisel osteotomy respectively .Then the duration of extraction and the intraoperative and postoperative complications were observed and recorded to assess the two methods .Results:The duration of extraction of drill group was shorter than chisel extraction group , which had statisti-cal differences between the two groups (P<0.05).The drill group had less postoperative complication such as ache , swelling, limited opening of mouth than those of the chisel extraction group (P<0.05).Occurrence of the inferior alveolar nerve injury , mandibular fracture , adjacent tooth damage and dry sock were lower than chisel extraction group (P<0.05).Conclusions:High-speed air tutbine drill with its evident superiority to traditional chisel , when applied in the extraction of low impacted teeth , can efficiently cut down duration of extraction , reduce the incidence of the intraoperative and postoperative complication and is therefore recommendable in clinical practice .%目的:对比高速涡轮气钻法与凿骨劈冠法拔除下颌水平埋伏阻生智齿的临床疗效。方法:回顾分析口腔门诊120颗低位水平阻生智齿患者的临床资料,其中采用传统的凿骨劈冠法拔除60颗为锤凿组,采用高速涡轮气钻拔除60颗为涡轮钻组,对2组手术时间及术中、术后并发症发生情况进行观察和对比分析。结果:涡轮钻组拔牙时间短于锤凿组,差异有统计学意义( P<0.05)。涡轮钻组术中邻牙损伤、下齿槽神经损伤和下颌角骨折的发生率以及术后颊面部的肿胀、疼痛程度、张口

  16. Efeitos da escarificação na qualidade física de um latossolo vermelho distroférrico após treze anos de semeadura direta Effects of chiseling on physical quality of a dystroferric red latosol after thirteen years of no-tillage

    Directory of Open Access Journals (Sweden)

    M. A. Araujo

    2004-06-01

    Full Text Available O objetivo deste trabalho foi avaliar as alterações na qualidade física de um Latossolo Vermelho distroférrico provocadas pela escarificação, após 13 anos de semeadura direta. O experimento constituiu-se de dois tratamentos: escarificação do solo a 0,30 m de profundidade (SDE e testemunha mantendo a semeadura direta (SD. Amostras de solo, com estrutura não deformada, foram coletadas nas profundidades de 0-0,15 m e 0,15-0,30 m, a partir das quais foram determinados a curva de retenção de água, a curva de resistência do solo à penetração, a densidade do solo e o "Intervalo Ótimo de Tensão da Água no Solo" (IOP. Os resultados mostraram que, na profundidade de 0-0,15 m, a escarificação promoveu modificações na porosidade do solo, mantendo condições adequadas de aeração em tensões matriciais menores do que 0,01 MPa. Por outro lado, no solo escarificado, constatou-se a maior ocorrência de limitações pela resistência do solo à penetração em tensões menores do que 1,5 MPa. Para a camada de 0,15-0,30 m, no tratamento SDE, a resistência do solo à penetração foi o limite superior do IOP. Os resultados deste estudo sugerem que, neste solo e sob esta condição de manejo, não é necessária a escarificação.The objective of this study was to evaluate alterations in the physical soil quality of a Dystroferric Red Latosol (Typic Haplorthox caused by chiseling, after thirteen years of no-tillage. The experiment consisted of two management systems: soil chiseling down to a 0.30 m depth (NTC and no-tillage (NT. Undisturbed soil samples were collected at depths of 0-0.15 m and 0.15-0.30 m, and the soil water retention curve, the soil resistance to penetration curve, the soil bulk density, and the "Least Limiting Water Potential" (LLWP were determined. The results showed that the chiseling caused modifications in soil porosity in the 0-0.15 m layer, maintaining appropriate aeration conditions in water matric potentials

  17. Eficiência da escarificação mecânica e biológica na melhoria dos atributos físicos de um latossolo muito argiloso e no incremento do rendimento de soja Efficiency of mechanical and biological chiseling in the improvement of physical attributes of a heavy clay oxisol and the increment of soybean yield

    Directory of Open Access Journals (Sweden)

    Rodrigo da Silveira Nicoloso

    2008-08-01

    tratamento ESC-Av teve comportamento intermediário. Os tratamentos SD-Nb+Av e ESC-Nb+Av aumentaram, em média, 46,6 % a lâmina de água infiltrada em relação aos tratamentos SD-Av e ESC-Av. O maior rendimento de grãos de soja foi observado no tratamento ESC-Nb+Av (3,73 Mg ha-1, que não diferiu significativamente do SD-Nb+Av (3,49 Mg ha-1. A escarificação mecânica do solo teve efeito temporário, e não foram constatadas melhores condições físicas do solo após nove meses, com exceção do aumento da porosidade total e macroporosidade do solo na camada 0-0,05 m. Por outro lado, a escarificação biológica aumentou a macroporosidade do solo, diminuiu sua resistência à penetração e melhorou a infiltração de água. A escarificação mecânica foi uma alternativa eficiente em melhorar as condições físicas do Latossolo textura muito argilosa quando associada à escarificação biológica, que preveniu a reconsolidação do solo.Compaction is one of the main causes of yield decreases in agricultural soils. Mechanical chiseling has been suggested to reduce soil compaction in long-term no-tillage systems. Another option to alleviate soil compaction is the use of cover crops, such as forage radish, with a well-developed tap root system and the capacity of growing into soil compacted layers, forming stable biopores and improving the soil physical properties. This study aimed to evaluate the efficiency of a mechanical (chisel plow and biological (forage radish soil decompaction method or the combination of both to improve the physical properties of a very clayey texture Oxisol and to increase soybean grain yield under no-tillage. The treatments were: black oat on no-till (NT-O, consortium of forage radish and black oat on no-till (NT-R+O, black oat on chiseled soil (CH-O and consortium of forage radish and black oat on chiseled soil (CH-R+O. The following properties were evaluated: soil bulk density, macroporosity, microporosity and total porosity in the layers 0

  18. Escarificação mecânica e biológica para a redução da compactação em argissolo franco-arenoso sob plantio direto Mechanical and biological chiseling to reduce compaction of a sandy loam alfisol under no-tillage

    Directory of Open Access Journals (Sweden)

    S. L. Abreu

    2004-06-01

    saturado, em médio prazo, a "escarificação biológica" (CM-crot mostrou-se mais eficaz na ruptura da camada compactada e estabelecimento de poros condutores de água do que a escarificação mecânica (Esc-soja do solo. Em contrapartida, se o indicador for a RP, o resultado é inverso. Assim, a propriedade hídrica ou mecânica do solo a ser usada como indicadora para a avaliação da eficácia da ruptura da camada compactada do solo depende do processo físico priorizado: a infiltração e redistribuição de água ou a penetração e crescimento de raízes.Soil management alters the physical soil properties and changes the soil air, water, and solute dynamics. Physical soil properties as affected by conservationist soil management systems were studied in a sandy loam Typic Hapludalf. The treatments were established on a soil that has been under no-tillage for 10 years, and consisted of: no-tillage soybeans, chisel tillage soybeans, reduced tillage Crotalaria, and bare soil without tillage. The evaluated soil properties were soil penetration resistance, bulk density, porosity, pore size distribution, saturated and unsaturated hydraulic conductivity, water infiltration using concentric rings or natural rainfall, variation of the volumetric soil moisture throughout the cropping cycle, and water retention curve. Soil penetration resistance (PR was highest at 0.075 m and 0.175 m depth in no-tillage and chiseled soil, respectively. Soil subsurface mobilization with chiseling and surface mobilization due to disking and sowing did not influence the bulk density (BD after the crop harvest. No-till soil under soybean crop had greater macroporosity than reduced tillage crotalaria and bare soil at 0.02 to 0.05 m depth, resulting in a greater saturated hydraulic conductivity and lower water retention during periods of low water availability. Among the analyzed soil physical-mechanical properties, PR seemed to be more sensitive to detect soil compaction than BD or porosities

  19. Алгоритм діагностики і вибору методу лікуваня пацієнтів з адентією верхніх латеральних різців = Algorithm of clinical inspection and choosing a method of treatment of patients from by the aedentia of overhead lateral chisels

    OpenAIRE

    Yakymets, A V; Drogomyrec'ka, M S

    2015-01-01

    Yakymets A V, Drogomyrec'ka M S. Алгоритм діагностики і вибору методу лікуваня пацієнтів з адентією верхніх латеральних різців = Algorithm of clinical inspection and choosing a method of treatment of patients from by the aedentia of overhead lateral chisels. Journal of Education, Health and Sport. 2015;5(5):233-242. ISSN 2391-8306. DOI 10.5281/zenodo.17596 http://ojs.ukw.edu.pl/index.php/johs/article/view/2015%3B5%285%29%3A233-242 https://pbn.nauka.gov.pl/works/559890 http://d...

  20. A New Model of Teaching Pedagogy in CHISEL for the 21th Century.

    Science.gov (United States)

    Huang, Li-yi

    This paper describes and compares six models for teaching second languages developed and adopted since 1840 (grammar-translation, direct, structural, situational, audiolingual, and communicative methods), and proposes a seventh, the cognitive-linguistic method, incorporating Noam Chomsky's theory of learning. The model takes both extralinguistic…

  1. Competition for IL-2 between regulatory and effector T cells to chisel immune responses

    Directory of Open Access Journals (Sweden)

    Thomas eHöfer

    2012-09-01

    Full Text Available In this review we discuss how the competition for cytokines between different cells of the immune system can shape the system wide immune response. We focus on interleukin-2 (IL-2 secretion by activated effector T cells (Teff and on the competition for IL-2 consumption between Teff and regulatory T cells (Treg. We discuss the evidence for the mechanism in which the depletion of IL-2 by Treg cells would be sufficient to suppress an autoimmune response, yet not strong enough to prevent an immune response. We present quantitative estimations and summarize our modeling effort to show that the tug-of-war between Treg and Teff cells for IL-2 molecules can be won by Treg cells in the case of weak activation of Teff leading to the suppression of the immune response. Or, for strongly activated Teff cells, it can be won by Teff cells bringing about the activation of the whole adaptive immune system. Finally, we discuss some recent applications attempting to achieve clinical effects through the modulation of IL-2 consumption by Treg compartment.

  2. The influence of vibration and noise from a handheld pneumatic (sculptors) chisel on the human cardiovascular system

    OpenAIRE

    Franken, Anja; Eloff, Frederik; Du Plessis, Johannes; Van Aarde, Michiel; Laubscher, Petrus

    2009-01-01

    Noise-induced hearing loss (NIHL) in the South African mining industry can be prevented, but only by incorporating more proactive and innovative measures into NIHL prevention programmes. At present, direct and indirect costs to the mining industry resulting from occupational noise are unacceptable and, more importantly, mineworkers' quality of life is being eroded. Researchers at the Council for Scientific and Industrial Research Laboratory for Mining Innovation (LMI) propose that the large d...

  3. Influence of chisel width on shear bond strength of composite to enamel = Influência da largura do cinzel sobre a resistência ao cisalhamento da união esmalte/resina composta

    Directory of Open Access Journals (Sweden)

    Oliveira, Antônio Carlos Castellan de

    2009-01-01

    Full Text Available Objetivo: Avaliar a influência de diferentes larguras de cinzel sobre a resistência de união ao cisalhamento na interface esmalte dental/resina composta. Metodologia: As coroas de 60 dentes incisivos bovinos foram incluídas em resina acrílica e as superfícies vestibulares de esmalte foram planificadas e condicionadas com ácido fosfórico a 35 %. O sistema adesivo Single Bond (3M/ESPE e de resina composta Z-250 (3M/ESPE foram utilizados para fabricar restaurações cilíndricas de resina composta perpendiculares à superfície plana do esmalte condicionado. Para o teste de cisalhamento, os espécimes foram submetidos ao ensaio mecânico com cinzéis de 0,5 mm, 1,0 mm, 2,0 mm ou 3,0 mm de largura da parte ativa romba, em uma máquina de ensaio universal à velocidade de 0,5 mm/min. Os dados obtidos foram analisados por análise de variância e teste de Duncan ao nível de significância de 5 %. Resultados: As médias de resistência de união ao cisalhamento dos grupos testados foram: 0,5 mm – 19,66 MPa; 1,0 mm – 18,78 MPa; 2,0 mm – 16,77 MPa; 3,0 mm –16,06 MPa. Houve diferença estatisticamente significativa entre os grupos de 0,5 e 3,0 mm (P=0,045, com uma relação inversa entre resistência de união ao cisalhamento e largura do cinzel. Conclusão: Os resultados sugerem que a resistência de união ao cisalhamento sofre influência da largura do cinzel utilizado no ensaio

  4. Influence of chisel width on shear bond strength of composite to enamel = Influência da largura do cinzel sobre a resistência ao cisalhamento da união esmalte/resina composta

    OpenAIRE

    Oliveira, Antônio Carlos Castellan de

    2009-01-01

    Objetivo: Avaliar a influência de diferentes larguras de cinzel sobre a resistência de união ao cisalhamento na interface esmalte dental/resina composta. Metodologia: As coroas de 60 dentes incisivos bovinos foram incluídas em resina acrílica e as superfícies vestibulares de esmalte foram planificadas e condicionadas com ácido fosfórico a 35 %. O sistema adesivo Single Bond (3M/ESPE) e de resina composta Z-250 (3M/ESPE) foram utilizados para fabricar restaurações cilíndricas de resina compost...

  5. Clinical efficacy analysis of minimally invasive surgery and hammer chisel technique for extracting residual root and crown in the elderly%微创术和锤凿术拔除老年人残根残冠的临床疗效分析

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    目的:探讨利用微创术和锤凿术拔除老年人残根残冠的临床疗效分析.方法:选取本院2013年5月至2015年5月收治的需行拔除残根残冠的符合研究条件的老年患者为研究对象,随机将患牙分为观察组140例以及对照组140例,对照组采用传统锤凿术拔除残根残冠,观察组采用牙科微创手术拔除残根残冠,分析两组患者手术时间、疼痛程度、拔牙窝完整性、断根发生率、干槽症及患者满意度情况.结果:观察组手术时间、疼痛程度、拔牙窝完整性评分均低于对照组,满意度评分高于对照组,差异有统计学意义(P<0.05),断根发生率、干槽症发生率观察组低于对照组,差异有统计学意义(P<0.05).结论:对拔除老年人残根残冠患者应用微创技术治疗具有高效、安全、无痛的特点,值得临床应用推广.

  6. Validação de teorias de simulação para operações com escarificadores em solo argiloso no planalto do Estado do Rio Grande do Sul, Brasil Validation of prediction theories to chisel plow in soils of Rio Grande do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    Paula Machado dos Santos

    2011-01-01

    Full Text Available O objetivo deste trabalho foi estudar teorias, utilizadas especialmente para simular situações reais de campo, contrastada por dados empíricos obtidos em condições reais de trabalho agrícola mecanizado em solo de textura argilosa com os resultados obtidos em trabalhos semelhantes realizados em outros países. Avaliou-se as demandas de tração de diferentes combinações entre velocidade e profundidade de trabalho de um escarificador. Buscou-se a representação gráfica da demanda requerida de força de tração e patinagem através da utilização do software Predição versão 1.0, contrastadas com resultados obtidos pela aplicação das teorias de predição Cn, Bn e Mn. As teorias preditivas Cn, Bn e Mn apresentam correlação boa com os valores experimentais, no entanto, existe uma superestimativa por parte das teorias comparadas aos valores medidos experimentalmente, para força de tração e patinagem, causando um dimensionamento do trator inadequado.The objective of this research was studied theories used specially to simulate real field situations contrasted by empiric data obtained in real real working conditions in mechanized agricultural clay soil with the results obtained in similar studies conducted in other countries. We tried to the graphical representation of the demand required traction force and slippage through the use of Prediction software version 1.0, contrasted with results obtained by applying the theories of prediction Cn, Bn and Mn. Predictive theories Cn, Bn and Mn have good correlation with experimental values, however, there is an overestimation by the theory compared to the values measured experimentally, for traction force and slippage, causing a tractor design inadequate.

  7. 76 FR 795 - Notice of Inventory Completion for Native American Human Remains and Associated Funerary Objects...

    Science.gov (United States)

    2011-01-06

    ... funerary objects for a Notice of Inventory Completion published in the Federal Register (67 FR 910-911... chisels, 3 polished stones, 8 celts, 2 faunal bones, 9 cupreous metal fragments and 1 cupreous metal...

  8. Research present situation and analysis on classification of rock drillability

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhi-hong; MA Qin-yong

    2001-01-01

    Rock drillability reflects the drill bit fragments rock hardly or easily. At present, rock drillability classification indexes have rock single-axle compressive strength, point load intensity,fracture stress during chiseling, drill speed, chiseling specific work, acoustic parameter, cutting magnitude, and so on. Every index reflects rock drillability but isn't overall. It is feasible that using many indexes of fuzzy mathematics method etc. to evaluate rock drillability.

  9. Urinary 1-naphthol and 1-pyrenol as indicators of exposure to coal tar products.

    Science.gov (United States)

    Heikkilä, P; Luotamo, M; Pyy, L; Riihimäki, V

    1995-01-01

    Chemical exposure of assemblers handling creosote-impregnated wood and of a single worker chiselling coal tar pitch layer was assessed by measuring airborne naphthalene and various polycyclic aromatic hydrocarbons (PAHs), and by measurement of urinary excretion of 1-naphthol and 1-pyrenol. The sum concentration of PAHs and of 4-6 aromatic ring-containing PAHs were high, 440 micrograms/m3 and 290 micrograms/m3, respectively, when chiselling. In the assembler's workplace, the PAH concentrations were about 1/50 of this value. Regarding airborne naphthalene concentrations the situation was reversed (assemblers, 1000 micrograms/m3; chiseller, 160 micrograms/m3). Correspondingly, the assemblers' urinary 1-napthol concentrations were 15-20 times higher than those of the chiseller. The urinary 1-pyrenol concentration of the chiseller was 2-4 times higher than among the assemblers. As the estimated pyrene inhalation doses among the assemblers could account for only about 2%-25% of the 24-h pyrenol excretion in urine, the skin was presumably the main route of uptake. For an assessment of the exposure to PAHs, air measurements, monitoring of metabolites in urine and preferably also data on the composition of the skin-contaminating product are needed.

  10. THE ANALYSIS OF MATHEMATICAL MODELS OF MECHANICAL SPEED OF DRIVING FOR OPTIMIZATION OF PROCESS OF DRILLING OF OIL AND GAS WELLS

    Directory of Open Access Journals (Sweden)

    Tsоuprikov A. A.

    2015-03-01

    Full Text Available The analysis of models is carried out from a definition position for system of optimum control of drilling of basic mathematical model on which calculation of optimum regime parameters is possible. The main equation for management of process of drilling of wells is the mathematical model of mechanical speed of a driving as function from axial load of a chisel, the speed of rotation of a chisel and a consumption of boring solution for cleaning of a well of destroyed breed. Key parameter is axial load of a chisel; graphically dependence of speed of drilling on loading has S appearance - a figurative curve of Bingham which has a convex mathematical extremum. In the article, domestic and foreign models of drilling are considered; their schedules according to skilled data of conducting of wells are constructed. Models are sedate, i.e. reflect only a linear site of a curve of Bingham, data of trade drilling is well approximated with initial and linear sites of curves. Thus, on them it is possible to make only rational management of process, and the optimum mode exists only on border of range of definition of function. Only the A.A. Pogarsky model is suitable for optimum control, having a mathematical maximum and S-shaped form of a curve. All models depend on two parameters of management – load of a chisel and speeds of rotation of a chisel and don't consider the third on influence on drilling speed parameter - a consumption of boring solution. Therefore, Pogarsky's model was finished by inclusion in it in an explicit form of a consumption of boring solution. Check of model by means of the regression analysis of skilled data of drilling from official reports of drilling foremen showed its reliability for 71-99%. The model allows carrying out optimum control of drilling in the "axial load of a chisel" parameter

  11. Modified ridge splitting and bone expansion osteotomy for placement of dental implant in esthetic zone

    Directory of Open Access Journals (Sweden)

    Mayur S Khairnar

    2014-01-01

    Full Text Available Ridge splitting with bone expansion is a technique of manipulation of bone to form receptor site for implant without removing any bone from the implant site. Maxillary bone has inherent quality of flexibility which can bemolded to desire location by using series of instrument namely chisels and osteotome. This further improves quality of bone all around implant, at the crest and apex both. This article describes a report of a clinical case with management of bucco-palatal ridge defect with modified ridge splitting and expansion osteotomy technique using chisel and osteotomes in an esthetic zone.

  12. Modified ridge splitting and bone expansion osteotomy for placement of dental implant in esthetic zone.

    Science.gov (United States)

    Khairnar, Mayur S; Khairnar, Darshana; Bakshi, Kedar

    2014-01-01

    Ridge splitting with bone expansion is a technique of manipulation of bone to form receptor site for implant without removing any bone from the implant site. Maxillary bone has inherent quality of flexibility which can bemolded to desire location by using series of instrument namely chisels and osteotome. This further improves quality of bone all around implant, at the crest and apex both. This article describes a report of a clinical case with management of bucco-palatal ridge defect with modified ridge splitting and expansion osteotomy technique using chisel and osteotomes in an esthetic zone. PMID:24808709

  13. The Cheops mystery targeted with neutrons

    NARCIS (Netherlands)

    Van de Graaf, A.

    2005-01-01

    How the ancient Egyptians managed to raise a seven million tonne pyramid in a time span of only twenty years remains a mystery. Every now and then discussions flare up as to how exactly the pyramids at Giza in Egypt were constructed. How could they cut stone without the necessary chisels? How did th

  14. Woodworking. A Bilingual Text = Carpinteria. Un Texto Bilingue.

    Science.gov (United States)

    Los Angeles Unified School District, CA. Div. of Career and Continuing Education.

    This booklet is a course of instruction in woodworking in a two-column, English-Spanish format. Following an introduction to woodworking and a lesson on safety, the booklet contains 19 units covering the following topics: wood; planning; laying out project parts; hand saws; planes; chisels and gouges; wood files and forming tools; boring holes in…

  15. Global Warming Potential of Organic and Conventional Grain Cropping Systems in the mid-Atlantic Region of the U.S.

    Science.gov (United States)

    The global warming potential (GWP) of a cropping system is the balance between the net exchange of the greenhouse gases CO2, N2O and CH4 that result from on-farm practices and the production and transport of inputs. We report here on GWP calculations for no-till (NT), chisel till (CT) and organic (O...

  16. CITA Working for and with material performance

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette

    2011-01-01

    The understanding of materials as active, whether compressed, under tension or flexed while handled, is at the root of all craft traditions. The ability to work a material, to saw and chisel wood, to weld and hammer steel or to weave and knit yarn relies on a profound understanding of its...

  17. 21 CFR 872.4565 - Dental hand instrument.

    Science.gov (United States)

    2010-04-01

    ..., operative dental amalgam carver, surgical bone chisel, operative amalgam and foil condenser, endodontic... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental hand instrument. 872.4565 Section 872.4565...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4565 Dental hand instrument. (a) Identification....

  18. Annual Research Review: Parenting and Children's Brain Development--The End of the Beginning

    Science.gov (United States)

    Belsky, Jay; de Haan, Michelle

    2011-01-01

    After questioning the practical significance of evidence that parenting influences brain development--while highlighting the scientific importance of such work for understanding "how" family experience shapes human development--this paper reviews evidence suggesting that brain structure and function are "chiselled" by parenting. Although the…

  19. Material characterization of ancient Indian copper

    Indian Academy of Sciences (India)

    A Srivastava; R Balasubramaniam

    2003-10-01

    A chalcolithic (2350–1800 BC) copper chisel from Balathal has been characterized by X-ray diffraction, microstructural and electrochemical methods. The surface patina was composed of sulfates and oxysulfates in the outer layers while the inner layers were rich in copper oxides. The chisel exhibited smaller grain sizes near two of the surfaces while the structure in the interior was equiaxed. The deformed grains and inclusions near the surfaces and variation in the microhardness of the sample from different faces proved that the copper chisel was processed by cold deformation after initial casting of the square cross-section chisel. The electrochemical behaviour of chalcolithic Cu has been compared with that of a modern Cu sample by potentiodynamic polarization studies. The corrosion rate of chalcolithic Cu in aerated 3.5% NaCl solution was only marginally higher than that of modern Cu. The higher rate of corrosion has been attributed to the presence of second phase sulfide inclusions. The excellent condition of preservation of the 3800-year-old copper object, with no indications of stress corrosion cracking, suggests that pure copper or copper-based materials can be seriously considered as candidate canister materials for long-term underground storage of nuclear wastes in underground repositories.

  20. Effects of injection systems and plastic mulches on distribution and emissions of cis- and trans-1,3-dichloropropene and chloropicrin.

    Science.gov (United States)

    Ou, Li-Tse; Thomas, John E; Allen, L Hartwell; Vu, Joseph C; Dickson, Donald W

    2007-08-01

    The concentration and distribution of a soil fumigant in the subsurface of field plots are two key factors in the determination of the fumigant efficacy. Subsurface concentrations of the biologically active compounds cis- and trans-1,3-dichloropropene (1,3-D) and chloropicrin (CP) were determined in soil at two adjacent injection traces and midpoint between the two traces in plastic-covered field beds after injection of the fumigant Telone C35 by conventional chisels or by a coulter rig (Avenger coulters). Two of the four beds were covered with metallic polyethylene film (MPE) and the remaining two were covered with virtually impermeable film (VIF). Three hours after chisel injection, concentrations of the three compounds at the two adjacent injection traces in the two beds were highly variable. Large concentrations of the compounds were detected at the side traces, whereas the compounds were not detected at the middle traces (bed centers) in the two chisel-injected beds covered with MPE or VIF. Initial concentrations of the three compounds at the two adjacent injection traces in the two Avenger-coulter-injected beds were more uniform than in the chisel-injected beds but still variable. Also, the three compounds had diffused horizontally to midpoint between the two injection traces in all four beds, generally in smaller concentrations. Concentrations of the three compounds in the shallow subsurface soil layer (0.5-30 cm) in the beds became progressively more uniform and then declined slowly. Volatilization losses from the two Avenger-coulter-injected beds and the chisel-injected bed covered with VIF were low. Combination of Avenger coulter injection and VIF provided better retention of the compounds in this soil layer and, thus, likely would provide better fumigant efficacy and crop yield.

  1. MAIZE YIELD AND ITS STABILITY AS AFFECTED BY TILLAGE AND CROP RESIDUE MANAGEMENT IN THE EASTERN ROMANIAN DANUBE PLAIN

    Directory of Open Access Journals (Sweden)

    Alexandru COCIU

    2015-10-01

    Full Text Available Rainfed crop management systems need to be optimized to provide more resilient options in order to cope with projected climatic scenarios which are forecasting a decrease in mean precipitation and more frequent extreme drought periods in the Eastern Romanian Danube Plain. This research, carried out in the period of 2011-2014, had as main purpose the determination of influence of tillage practices and residue management on rainfall use efficiency, maize yield and its stability, in order to evaluate the advantages of conservation agriculture (CA in the time of stabilization of direct seeding effects, in comparison with traditional chisel tillage. The maize grain yields are presented for each crop management practices, as follows: (1 chisel tillage, retained crop residues being chopped and incorporated (ciz; (2 zero tillage, retained crop residue chopped and kept on the field in short flat condition (rvt; (3 zero tillage, crop residues kept on the field in short root-anchored condition (1/2rva, and (4 zero tillage, crop residues kept on the field in tall root-anchored condition (1/1rva. In 2012, a year with prolonged drought during vegetative growth, yield differences between zero tillage with short root-anchored residue retention (1/2rva and chisel tillage with residue incorporation (ciz were positive, up to 840 kg ha-1. In average over 2011-2014, conservation agriculture (CA practices had a yield advantage over traditional chisel tillage practice. Zero tillage with residue retention used rainfall more efficiently so suggesting that it is a more resilient agronomic system than traditional (conventional practices involving chisel tillage with residue incorporation.

  2. Assessing the Soil Physiological Potential Using Pedo-Biological Diagnosis Under Minimum-Tillage System and Mineral Fertilization

    Directory of Open Access Journals (Sweden)

    Lazar Bireescu

    2014-11-01

    Full Text Available The main objective of sustainable agriculture is the protection of environment and natural vegetal and soil resources. Accordingly, the objective of this research was to assess the impact of technological systems by minimum tillage on soil biological activity, using the Pedo-Biological Diagnosis of Soil Resources. Our research was conducted on haplic chernozem from Experimental Station of UASVM of Iasi, Romania, during the seasonal dynamic, to the soybean crop, on unfertilized and fertilized agrofond, using moderate mineral doses (N80P80 as average of 2009–2010 period, under minimum tillage (2x disk, paraplow, chisel compared to conventional (plugging at 20 cm and 30 cm. In the case of soil works with chisel and paraplow without return of furrow, the Pedo-Biological Diagnosis highlights an increase of soil physiological potential, in the both variants (unfertilized and fertilized, unlike the method of alternating the depth of plugging that proved to be ineffective.

  3. The earliest herbivorous marine reptile and its remarkable jaw apparatus.

    Science.gov (United States)

    Chun, Li; Rieppel, Olivier; Long, Cheng; Fraser, Nicholas C

    2016-05-01

    Newly discovered fossils of the Middle Triassic reptile Atopodentatus unicus call for a radical reassessment of its feeding behavior. The skull displays a pronounced hammerhead shape that was hitherto unknown. The long, straight anterior edges of both upper and lower jaws were lined with batteries of chisel-shaped teeth, whereas the remaining parts of the jaw rami supported densely packed needle-shaped teeth forming a mesh. The evidence indicates a novel feeding mechanism wherein the chisel-shaped teeth were used to scrape algae off the substrate, and the plant matter that was loosened was filtered from the water column through the more posteriorly positioned tooth mesh. This is the oldest record of herbivory within marine reptiles. PMID:27386529

  4. Impressive: printmaking, letterpress and graphic design

    OpenAIRE

    Wood, Philippa

    2010-01-01

    Inspired by the challenge of hands-on tweaks and unpredictable results as well as the tactile qualities of different inks, papers, and binding techniques, today’s creatives are rediscovering old-fashioned printing methods and crafts. Impressive is a topical exploration of the interplay between current trends in graphic design and traditional handiwork such as letterpress printing, hand-cut linotype, chiselled woodblocks, and embossing. In addition to a rich selection of invitations, business ...

  5. Sugar cane management with humic extract and organic and mineral fertilizer: impacts on Oxisol some physical properties

    Science.gov (United States)

    Alves, M. C.; Campos, F. S.; Souza, Z. M.

    2012-04-01

    The present investigation has as objective to study the impact of cultive systems, humic extract and organic and mineral fertilizers on Oxisol some physical properties cultivated of sugar cane. It was developed in Aparecida do Taboado, Mato Grosso do Sul, Brazil, in Manufactores Alcoolvale. The study was in sugar cane culture implanted on 3th and 4th cycle. The experimental design was at randomized blocks following scheme in zone with eight treatments and four replications. The two treatments in main zone were represented by cultivation systems (with and without chisel) and the subzone fertilization (T1-mineral, T2-mineral+sugar cane residue, T3-mineral+humic and fulvic acids and T4-mix of mineral, sugar cane residue and humic and fulvic acids). In three soil layers: 0.00-0.05; 0.10-0.20 and 0.20-0.40 m were studied the physical soil properties: macroporosity, microporosity, total porosity and soil bulk density. Also evaluate the technological quality of sugar cane. The conclusions are: the application of mineral fertilizer+sugar cane residue+humic extract (Humitec ®) and cropping system with chisel were more effective in improving soil physical; the system of crop of sugar cane ratton implanted in the 2th and 3th cycle, without the use of chisel was better in the recovery of soil physical properties; the crop system without the chisel and the combination of mineral fertilizer+sugar cane residue was promising to increase of Brix, Pol juice, Pol sugar cane and total recoverable sugars Pol.

  6. 木材加工教育用ビデオ教材の制作(2) : 手彫りによる中仕工かんな台の製作

    OpenAIRE

    番匠谷, 薫; 池田, 豊; 矢田部, 敏夫; 藤元, 嘉安; 真鍋, 正男

    1993-01-01

    Formerly in Japan, carpenter's making of plane stock made of shirakashi (Quercus myrsinaefolia Blume) of Japanese hand plane was done by hand making with chisel. This traditional concept of hand making of wooden plane stock can be regarded to be very important for teachers of industrial arts of junior high schools in Japan because its making skill can lead them to deep understandings of the Japanese hand plane. It also provides a totally skilled back ground concerning the Japanese hand plane ...

  7. Modified ridge splitting and bone expansion osteotomy for placement of dental implant in esthetic zone

    OpenAIRE

    Mayur S Khairnar; Darshana Khairnar; Kedar Bakshi

    2014-01-01

    Ridge splitting with bone expansion is a technique of manipulation of bone to form receptor site for implant without removing any bone from the implant site. Maxillary bone has inherent quality of flexibility which can bemolded to desire location by using series of instrument namely chisels and osteotome. This further improves quality of bone all around implant, at the crest and apex both. This article describes a report of a clinical case with management of bucco-palatal ridge defect with mo...

  8. Optical coherence tomography to evaluate the interaction of different edge designs of four different silicone hydrogel lenses with the ocular surface

    OpenAIRE

    Turhan, Semra

    2015-01-01

    Semra Akkaya Turhan, Ebru Toker Department of Ophthalmology, School of Medicine, University of Marmara, Istanbul, Turkey Purpose: To evaluate the lens edge interaction with the ocular surface with different edge designs using optical coherence tomography and to examine the effect of lens power on the lens edge interactions. Methods: Four types of silicone hydrogel lenses with different edge designs (round-, semi-round-, chisel-, and knife-edged) at six different powers (+5.0, +3.0,...

  9. Optical coherence tomography to evaluate the interaction of different edge designs of four different silicone hydrogel lenses with the ocular surface

    OpenAIRE

    Turhan SA; Toker E

    2015-01-01

    Semra Akkaya Turhan, Ebru Toker Department of Ophthalmology, School of Medicine, University of Marmara, Istanbul, Turkey Purpose: To evaluate the lens edge interaction with the ocular surface with different edge designs using optical coherence tomography and to examine the effect of lens power on the lens edge interactions. Methods: Four types of silicone hydrogel lenses with different edge designs (round-, semi-round-, chisel-, and knife-edged) at six different powers (+5.0, +3.0, +1....

  10. Effect of soil moisture deficit in the upper root zone on growth and yield of soybeans

    Energy Technology Data Exchange (ETDEWEB)

    Anwar-ul-Haq; Brown, D.A.

    Soybean producers in Arkansas frequently are confronted with drought conditions which limit yields. These moisture deficit periods result in decreased water and nutrient absorption which adversely affects root growth and distribution within the soil profile, bloom set, and seed-pod retention. Producers have attempted to eliminate this problem by irrigation, by the use of drought tolerant cultivars, and by chiseling to provide for greater root penetration into the subsoil.

  11. The Impact of Various Types of Tillage on the Soil Water Availability

    OpenAIRE

    BESNIK GJONGECAJ; PIRRO VEIZI

    2014-01-01

    The present study is focused on the role that various ways of soil tillage may have on the increase of soil water availability to the plant roots. The research was carried out in Tirana, Albania, and the experiment was established in a vineyard field. The soil was cultivated in three different ways (three treatments): conventional (plowing plus surface cultivation), conservative (subsoiling plus surface cultivation), conservative (chisel plowing plus surface cultivation). In order to quantify...

  12. Effect of cultural practices and fertilizers on sunflower yields in long term experiments

    OpenAIRE

    Petcu Gh; Petcu E.

    2006-01-01

    Field experiments were conducted during 1980-2004 at Agricultural Research and Development Institute from Fundulea (Romania) on a leached chernozem soil, well drained, formed on loess, with 33% clay content and 2.8% organic matter in the arable layer. The paper presents aspects regarding the influence of different soil tillage methods (moldboard plow, chisel paraplow, disking), fertilizers and track by track successive passings of tractor (from 1 to 3) prior to seedbed preparation on sunflowe...

  13. Critical limits of soil penetration resistance in a rhodic Eutrudox

    Directory of Open Access Journals (Sweden)

    Moacir Tuzzin de Moraes

    2014-02-01

    Full Text Available Soil penetration resistance is an important indicator of soil physical quality and the critical limit of 2 MPa has been widely used to characterize the soil physical quality, in both no-tillage and conventional systems. The aim of this study was to quantify the influence of different tillage and cropping systems on the soil penetration resistance in a Rhodic Eutrudox. The experiment was carried out in a 5 × 2 factorial, completely randomized block design (tillage systems vs cropping systems, with four replications. The tillage systems consisted of: conventional tillage disk harrow; minimum tillage with annual chiseling; minimum tillage with chiseling every three years; no-tillage for 11 consecutive years; and no-tillage for 24 consecutive years. The factor cropping systems was represented by: crop rotation and crop succession. The soil penetration resistance (SPR was determined in 20 soil samples per treatment and layer (0.0-0.10; 0.10-0.20 and 0.20-0.30 m for each soil matric potential: -6, -10, -33, -100, -500 kPa. The SPR was determined at a volumetric soil water content equivalent to the fraction of plant-available water of 0.7. There were no differences of soil penetration resistance between the two cropping systems. Differences in soil penetration resistance among tillage systems were related to the matric potential at which the samples were equilibrated. The critical SPR limit of 2 MPa normally used for conventional tillage should be maintained. However, this value of 2 MPa is inappropriate for the physical quality characterization of Rhodic Eutrudox under no-tillage and/or minimum tillage with chiseling. Regardless of the cropping systems, the critical SPR limit should be raised to 3 MPa for minimum tillage with chiseling and to 3.5 MPa for no-tillage.

  14. Influence of different soil preparation techniques on organically grown strawberries

    OpenAIRE

    Leona, Brockamp; Eis, Birgit

    2008-01-01

    From June 2005 till June 2007 different soil preparation techniques like chiselling and advance sowing of medicinal plants and green manuring were proofed for their influence on reducing plant losses of strawberries caused by root diseases like Phytophthora species and Verticillium dahliae. The variants were combined with potted plants and Frigos. The experiment took place on an organic fruit farm near Stuttgart, Germany, with the strawberry variety ´Elsanta´. Focused on root diseases, hab...

  15. An Effective Method for Improvement of Field Electron Emission Site Density and Uniformity of Amorphous Carbon Thin Films

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Ping; WANG Li-Jun; ZHANG Bing-Lin; YAO Ning; ZANG Qi-Ren; CHEN Jun; DUAN Xin-Chao

    2006-01-01

    @@ Amorphous carbon films are deposited on the Mo film/ceramic substrates, which are pretreated by a laser spat-tering chiselling technique (2 line/mm), by using the microwave chemical vapour deposition technique. The films are characterized by x-ray diffraction, Raman spectrum, optical microscopy, and scanning electron microscopy.The experimental result indicates that the laser spattering chiselling pretreated techniques can essentially improve the field emission uniformity and the emission site density of the amorphous carbon thin film devices so that its emission site density can reach the level of actual application (undistinguishable by naked eye) from a broad well-proportioned emission area of 50mm × 50mm. This kind of device can show various digits and words clearly. The lowest turn-on field below 1 V/m, the emission current density over 5.0 ±0.1 mA/cm2, and the highest luminance 1.0 × 103 cd/m2 are obtained. Meanwhile, the role of the laser spattering chiselling techniques in improving the field emission properties of the amorphous carbon film are explained.

  16. Optimization of process parameters in drilling of GFRP composite using Taguchi method

    Directory of Open Access Journals (Sweden)

    Vinod Kumar Vankanti

    2014-01-01

    Full Text Available The objective of the present work is to optimize process parameters namely, cutting speed, feed, point angle and chisel edge width in drilling of glass fiber reinforced polymer (GFRP composites. In this work, experiments were carried out as per the Taguchi experimental design and an L9 orthogonal array was used to study the influence of various combinations of process parameters on hole quality. Analysis of variance (ANOVA test was conducted to determine the significance of each process parameter on drilling. The results indicate that feed rate is the most significant factor influencing the thrust force followed by speed, chisel edge width and point angle; cutting speed is the most significant factor affecting the torque, speed and the circularity of the hole followed by feed, chisel edge width and point angle. This work is useful in selecting optimum values of various process parameters that would not only minimize the thrust force and torque but also reduce the delimitation and improve the quality of the drilled hole.

  17. Tillage and nutrient source effects on water quality and corn grain yield from a flat landscape.

    Science.gov (United States)

    Thoma, David P; Gupta, Satish C; Strock, Jeffrey S; Moncrief, John F

    2005-01-01

    Beneficial effects of leaving residue at the soil surface are well documented for steep lands, but not for flat lands that are drained with surface inlets and tile lines. This study quantified the effects of tillage and nutrient source on tile line and surface inlet water quality under continuous corn (Zea mays L.) from relatively flat lands (<3%). Tillage treatments were either fall chisel or moldboard plow. Nutrient sources were either fall injected liquid hog manure or spring incorporated urea. The experiment was on a Webster-Canisteo clay loam (Typic Endoaquolls) at Lamberton, MN. Surface inlet runoff was analyzed for flow, total solids, NO(3)-N, NH(4)-N, dissolved P, and total P. Tile line effluent was analyzed for flow, NO(3)-N, and NH(4)-N. In four years of rainstorm and snowmelt events there were few significant differences (p < 0.10) in water quality of surface inlet or tile drainage between treatments. Residue cover minimally reduced soil erosion during both snowmelt and rainfall runoff events. There was a slight reduction in mineral N losses via surface inlets from manure treatments. There was also a slight decrease (p = 0.025) in corn grain yield from chisel-plow plots (9.7 Mg ha(-1)) compared with moldboard-plow plots (10.1 Mg ha(-1)). Chisel plowing (approximately 30% residue cover) alone is not sufficient to reduce nonpoint source sediment pollution from these poorly drained flat lands to the extent (40% reduction) desired by regulatory agencies.

  18. MANEJO DO SOLO E CRESCIMENTO INICIAL DE Eucalyptus grandis Hill ex Maiden EM ARGISSOLO

    Directory of Open Access Journals (Sweden)

    Juliana Prevedello

    2013-01-01

    Full Text Available The forest species cultivation with rapid growth in Brazil has increased, mainly due to the diverse use of its wood and climate adaptation. The cultivation with minimum tillage in the forest sector stands out a way to increase productivity, combined with the maintenance of biodiversity and soil conservation. This study was conducted at the experimental area of State Foundation for Agricultural Research - Research Center for Forestry in Santa Maria - RS, with aimed to evaluate the effect of the soil tillage methods on soil physical properties and on initial development of Eucalyptus grandis, in a sandy loam Typic Hapludalf. Four soil management practices were compared: no-tillage; chisel tillage; chisel tillage plus harrowing and; rotary tillage (rotary tiller, installed in a randomized block design with three replications. The soil under no-tillage conditioned lower initial growth of eucalyptus due higher soil penetration resistance and bulk density, when compared with treatments with mobilization. The root distribution analysis in soil, despite being a qualitative method, was effective in demonstrating the effect of soil tillage for the Eucalyptus grandis plantation. The soil tillage with mobilization resulted in a higher initial growth of Eucalyptus grandis. The chisel tillage effects in the soil physical properties persisted after one year of soil tillage.

  19. Oil Palm Workers: Designing Ergonomics Harvesting Tool Us¬ing User Centered Design Approach to Reducing Awkward Body Posture by Catia Simulation

    Directory of Open Access Journals (Sweden)

    Irwan Syah MOHD YUSOFF

    2015-10-01

    Full Text Available Background: The aim of this study is to develop a new ergonomics chisel based on user centered design approach and to evaluate the effectiveness for reducing awkward posture using CATIA software for simulation analysis.Methods: Respondents were selected using purposive sampling – age 18 – 49 years old, men, experience using chisel (>1 month. A set of questionnaire were used to interview workers while postural risks were determined using Rapid Upper Limb Assessment (RULA. Selected anthropometric parameters were taken and user centered design concept were applied to determine mismatch and to facilitate design process. CATIA software was used to integrate the results of postural analysis and anthropometric measurement using 3D modeling.Results: A total of 273 male harvesters participated in this study. The result shows 5.2% of the chisels’ length of handles matches with the respondents whereas none (100% of the chisels’ circumference of handle matches with respondents’ internal grip diameter. Tool-chisel usage, majority of harvester bend forward while harvesting (96.7% and most of workers having blister (83.2%, redness (85.3% and numbness (65.9% during harvesting. RULA simulation analysis showed the score action level for new design is 3(further investigated need and changes may be required compared to existing tool are in action score 7(investigated and changes required immediately.Conclusions: The study showed that the design of new harvesting tool has the potential to reduce awkward body posture during harvesting activities as compared to existing tools. Keywords: Harvesting tool, Awkward posture, User centered design, CATIA simulation

  20. [Successful treatment using detachable coils for traumatic carotid cavernous fistula as a complication of transsphenoidal surgery for a pituitary adenoma: a case report].

    Science.gov (United States)

    Kobayashi, N; Abe, T; Furuya, H; Dohi, K; Shimazu, M; Sasaki, K; Izumiyama, H; Matsumoto, K; Ohki, S; Nemoto, S

    2000-02-01

    We report a case of a patient with traumatic carotid cavernous fistula (CCF) caused by transnasal-transsphenoidal surgery, who was successfully treated using detachable coils. A 47-year-old man was admitted to our hospital because of severe headache. He was confirmed to have a nonfunctioning pituitary adenoma with presellar-type sphenoid sinus. Cerebral angiography initially disclosed no vascular lesions. A transnasal-transsphenoidal adenomectomy was performed. When the anterior wall of the sphenoid sinus was dissected with a chisel, the chisel deeply stuck into the posterolateral part of the sinus. Profuse arterial bleeding was observed through the sphenoid sinus. The bleeding was stopped easily by compression and packing with bone wax. The operation was continued, the sellar floor was opened widely and the tumor was removed subtotally. The medial wall of the cavernous sinus was intact. Histological examination revealed a pituitary adenoma. Immediately after surgery, the patient noticed a bruit. He developed chemosis and abducent palsy on the right side. Cerebral angiography displayed a high-flow CCF, which was attributed to the carotid artery injury caused by the transnasal-transsphenoidal surgery. The CCF disappeared after two-staged embolization using detachable coils, 1st transvenous and 2nd transarterial. Ten months later, cerebral angiography showed persistent occlusion of the fistula, and the patient experienced no tumor recurrence. It is suggested that drilling is a safer procedure than using a chisel for dissection of a sphenoid sinus with incomplete pneumatization. Endovascular treatment using detachable coils proved useful to manage the CCF, an unusual complication of transsphenoidal surgery.

  1. Distribution of Field Corn Roots and Parasitic Nematodes in Subsoiled and Nonsubsoiled Soil

    OpenAIRE

    Rich, J. R.; Hodge, C.; Robertson, W. K.

    1986-01-01

    A field trial was conducted for 2 years in an Arredondo fine sand containing a tillage pan at 15-20 cm deep to determine the influence of subsoiling on the distribution of corn roots and plant-parasitic nematodes. Soil samples were taken at various depths and row positions at 30, 60, and 90 days after planting in field corn subsoiled under the row with two chisels and in non-subsoiled corn. At 30 and 60 days, in-row nematode population densities to 60 cm deep were not affected by subsoiling c...

  2. MATHEMATICAL MODEL AND CALCULATING METHOD OF PARAMETERS FOR TWIST DRILL HYPERBOL

    Institute of Scientific and Technical Information of China (English)

    WangMin; ZuoDunwen; LiChao

    2002-01-01

    Mathematical model for hyperboloid grinding of twist drill and relationships between drill design and grinding parameters are introduced.Point angles at outer corner and chisel edge corner are proposed to be used as the drill design parameters to determine the type uniquely and the relicf andgle is used as a supplement parameter.Function relations between the twist drill design and the grinding parameters are derived.Hence a theeoretical basis is estab-lised for design and grinding of the hyperboloid twist drill.

  3. Optical coherence tomography to evaluate the interaction of different edge designs of four different silicone hydrogel lenses with the ocular surface

    Directory of Open Access Journals (Sweden)

    Turhan SA

    2015-05-01

    Full Text Available Semra Akkaya Turhan, Ebru Toker Department of Ophthalmology, School of Medicine, University of Marmara, Istanbul, Turkey Purpose: To evaluate the lens edge interaction with the ocular surface with different edge designs using optical coherence tomography and to examine the effect of lens power on the lens edge interactions. Methods: Four types of silicone hydrogel lenses with different edge designs (round-, semi-round-, chisel-, and knife-edged at six different powers (+5.0, +3.0, +1.0, -1.0, -3.0, and -5.0 diopters were fitted to both eyes of 20 healthy volunteers. Optical coherence tomography images were taken at the corneal center and at the limbus within 15–30 minutes after insertion. The images were evaluated with respect to two parameters: conjunctival indentation exerted by the lens edge; and the tear film gaps between the posterior surface of the lens and the ocular surface. The amount of conjunctival indentation was measured with the distortion angle of the conjunctiva at the lens edge. Results: The degree of conjunctival indentation was highest with the chisel-edged design followed by the semi-round design (P<0.0001. Knife- and round-edged lenses exerted similar levels of conjunctival indentation that was significantly lower compared to chisel-edged lens (P<0.001. For each one of the tested lens edge designs, no significant difference was observed in the conjunctival indentation with respect to lens power. The chisel-edged lens produced the highest amount of conjunctival indentation for each one of the six lens powers (P<0.0001. Post-lens tear film gaps at the limbus were observed at most in the round-edge design (P=0.001. Conclusion: The fitting properties of contact lenses may be influenced by their edge design but not by their lens power. Keywords: Acuvue Oasys, Air Optix Aqua, PremiO, PureVision 2 HD, silicone hydrogel contact lenses

  4. Comparison of the Effects of No Tillage, Minimum Tillage and Conventional Tillage on Dry Land Wheat Yield in Pebbly Field in Tropical Region

    OpenAIRE

    N Loveimi; M. Safari; N Heidarpour

    2016-01-01

    The current study was conducted to compare different tillage methods on wheat yield in pebbly dry land areas done within three years (2006-2008) in north Khouzestan (Baghmalek city) in randomized block design with five treatments and four replications. The experimental treatments were:(1)chisel plow +seed-drill, (2)Semi plow(mold board plow with remove mold board)+seed-drill, (3)no-till-drill, (4)sweep plow +seed-drill and (5)conventional method(mold board plow+ broadcasting seed and fertiliz...

  5. Occurrence of Euplatypus parallelus, Euplatypus sp. (col.: Euplatypodidae and Xyleborus affinis (col.: Scolytidae in Pinus sp. in Ribas do Rio Pardo, Mato Grosso do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Zanuncio José Cola

    2002-01-01

    Full Text Available Wood borer species of the families Euplatypodidae and Scolytidae were observed attacking trees of Pinus sp. in the Municipality of Ribas do Rio Pardo, state of Mato Grosso do Sul, Brazil, in March 2000. This plantation had been previously burned in an accidental fire in January 2000, causing the trees to become partially or totally unhealthy, rendering them more susceptible to attack of these pests. Galleries of these wood borers were opened with a chisel to observe parameters such as their direction and form of these galleries. Species observed as wood borers of Pinus sp. were Euplatypus parallelus, Euplatypus sp. (Coleoptera: Euplatypodidae and Xyleborus affinis (Coleoptera: Scolytidae.

  6. Gold and Silver Inlaid Bronze Sheep

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Gold and silver inlaying is a metal processing technique popular during the Spring and Autumn Period (770-476 B. C.) and the Warring States Period (475-221 B. C.). Patterns on the surface of the bronze figure are chiselled out and gold and silver threads (which can be as thin as hair) are inlaid. Finally the whole figure is filed and polished resulting in a splendid artistic work highlighting the different colours of the three different kinds of metal. The artifact shown here was unearthed from Ningxia'...

  7. Effects of 24 Years of Conservation Tillage Systems on Soil Organic Carbon and Soil Productivity

    OpenAIRE

    Olson, Kenneth R.; Stephen A. Ebelhar; James M. Lang

    2013-01-01

    The 24-year study was conducted in southern Illinois (USA) on land similar to that being removed from Conservation Reserve Program (CRP) to evaluate the effects of conservation tillage systems on: (1) amount and rates of soil organic carbon (SOC) storage and retention, (2) the long-term corn and soybean yields, and (3) maintenance and restoration of soil productivity of previously eroded soils. The no-till (NT) plots did store and retain 7.8 Mg C ha−1 more and chisel plow (CP) −1.6 Mg C ha−1 ...

  8. Correction of resistance to penetration by pedofunctions and a reference soil water content

    Directory of Open Access Journals (Sweden)

    Moacir Tuzzin de Moraes

    2012-12-01

    Full Text Available The soil penetration resistance is an important indicator of soil compaction and is strongly influenced by soil water content. The objective of this study was to develop mathematical models to normalize soil penetration resistance (SPR, using a reference value of gravimetric soil water content (U. For this purpose, SPR was determined with an impact penetrometer, in an experiment on a Dystroferric Red Latossol (Rhodic Eutrudox, at six levels of soil compaction, induced by mechanical chiseling and additional compaction by the traffic of a harvester (four, eight, 10, and 20 passes; in addition to a control treatment under no-tillage, without chiseling or additional compaction. To broaden the range of U values, SPR was evaluated in different periods. Undisturbed soil cores were sampled to quantify the soil bulk density (BD. Pedotransfer functions were generated correlating the values of U and BD to the SPR values. By these functions, the SPR was adequately corrected for all U and BD data ranges. The method requires only SPR and U as input variables in the models. However, different pedofunctions are needed according to the soil layer evaluated. After adjusting the pedotransfer functions, the differences in the soil compaction levels among the treatments, previously masked by variations of U, became detectable.

  9. INFLUENCE OF SOIL TILLAGE AND LOW HERBICIDE DOSES ON WEED POPULATIONS AND SPRING BARLEY YIELD

    Directory of Open Access Journals (Sweden)

    Mira Knežević

    2003-06-01

    Full Text Available The influence of different tillage variants and low herbicide doses of triasulfuron & chlortoluron mixture (Dicuran forte 80 WP on weed populations and crop yield were studied in spring barley on lessive pseudogley soil in North-Eastern Croatia at the Čačinci locality in 1999. Tillage had no significant influence on annual broad-leaved weed biomass production, which was 22 kg ha-1 , on the average. Chisel ploughing and disk harrowing significantly increased perennial weed biomass by 21 and 44 times, respectively compared to mouldboard ploughing. The average efficacy of total weed biomass control was 95, 89 and 81% at full, onehalf and one-quarter of the recommended herbicide dose, respectively and did not differ very much between tillage treatments. Both reduced herbicide doses ensured very good biomass control of the most abundant weed populations such as Ambrosia artemisiifolia L., Chenopodium album L., Ch. polyspermum L. and Polygonum lapathifolium L. No significant tillage and herbicide dose effects were recorded in barley yields, which ranked from 4.93 t ha-1 in chisel ploughing to 4.48 t ha-1 in disk harrowing. These results suggested a possibility of mouldboard ploughing substitution with reduced tillage practices on lessive pseudogley soil and herbicide dose reduction of triasulfuron & chlortoluron mixture to 50% or more in spring barley.

  10. Crop and Soil Responses to Using Corn Stover as a Bioenergy Feedstock: Observations from the Northern US Corn Belt

    Directory of Open Access Journals (Sweden)

    Jane M. F. Johnson

    2013-02-01

    Full Text Available Corn (Zea mays L. stover is a potential bioenergy feedstock, but little is known about the impacts of reducing stover return on yield and soil quality in the Northern US Corn Belt. Our study objectives were to measure the impact of three stover return rates (Full (~7.8 Mg ha−1 yr−1, Moderate (~3.8 Mg ha−1 yr−1 or Low (~1.5 Mg ha yr−1 Return on corn and soybean (Glycine max. L [Merr.] yields and on soil dynamic properties on a chisel-tilled (Chisel field, and well- (NT1995 or newly- (NT2005 established no-till managed fields. Stover return rate did not affect corn and soybean yields except under NT1995 where Low Return (2.88 Mg ha−1 reduced yields compared with Full and Moderate Return (3.13 Mg ha−1. In NT1995 at 0–5 cm depth, particulate organic matter in Full Return and Moderate Return (14.3 g kg−1 exceeded Low Return (11.3 g kg−1. In NT2005, acid phosphatase activity was reduced about 20% in Low Return compared to Full Return. Also the Low Return had an increase in erodible-sized dry aggregates at the soil surface compared to Full Return. Three or fewer cycles of stover treatments revealed little evidence for short-term impacts on crop yield, but detected subtle soil changes that indicate repeated harvests may have negative consequences if stover removed.

  11. Reducing ploughing depth and nitrogen fertilisation in hilly environment of the centre of italy (marche

    Directory of Open Access Journals (Sweden)

    Domenico Laureti

    2007-07-01

    Full Text Available For the purpose to provide a contribution about ploughing subject three ways were compared in a quadriennal rotation from Experimental Industrial Crops Institute in Osimo. During the years 1986-1999, in a factorial experiment with 4 replications, traditional (50 cm, shallow ploughing (25 cm and chiseling (50 cm plus reduced ploughing (25 cm were compared with two crop rotations (sugar beet- wheat; shelling peas-wheat and three nitrogen levels (0, 92, 184 kg ha-1 in a split block experiment. The conventional and chiseling plus reduced ploughing did not influenced sugar-beet or peas yield or qualitative and quantitative crop traits; like it was emphasized in the previous seven years. Wheat seed yield was positively influenced by reduced ploughing done to the previous crop but not by rotation. Straw yield was higher after sugar beet than after peas. Nitrogen fertilisation allowed the best technical yield of wheat at the intermediate level of 90 kg ha-1, whereas more nitrogen (180 kg ha-1 improved only the biomass and heads per squared meter at harvesting, lowering the test weight of wheat. In conclusion we could affirm that, in this experience, the best ploughing for sugar-beet and shelling peas is at 25 cm. Moreover it was not possible to reduce fertilisation of wheat following shelling peas (leguminous crop.

  12. Effects of foreign object damage from small hard particles on the high-cycle fatigue life of titanium-(6)aluminum-(4)vanadium

    Science.gov (United States)

    Hamrick, Joseph L., II

    Thin rectangular samples of Ti-6Al-4V were damaged by four methods to represent foreign object damage found in turbine engine blades: (1) impact with 2 mm. and 5 mm diameter glass spheres at 305 m/s, (2) impact with 2 mm and 4 mm diameter steel spheres at 305 m/s, (3) quasi-static displacement controlled indentation using steel chisels with 1 mm, 2 nun and 5 mm diameter tips and (4) shearing notches with a 2 mm. diameter chisel point under a quasi-static loading condition. Finite element analysis was used to study the relationship between the stress state created by the plastic damage and the fatigue strength. A new method of quantifying the amount of plastic damage from multiple methods was developed. The fatigue strength required for crack initiation at 10E7 cycles was found to be a function of the total depth from the edge of the undeformed specimen up to the end of the plastically deformed zone. For damage depths less than 1750 mum, the reduction in fatigue strength is proportional to the depth of total damage. For depths > 1750 mum, there appears to be a threshold value of fatigue strength.

  13. Tool-related injuries among amateur and professional woodworkers.

    Science.gov (United States)

    Becker, T M; Trinkaus, K M; Buckley, D I

    1996-10-01

    Although woodworking is a popular hobby and the woodworking industry employs thousands of workers nationwide, few studies have examined injuries associated with this activity, especially in relation to woodshop tool use. We conducted a survey of amateur and professional woodworkers (n = 283) in New Mexico to determine histories and rates of tool-specific injuries. Injuries associated with woodshop tool use were reported by 64% of all respondents. Hammers, chisels/gouges, and table saws were most frequently reported in association with injuries, although the highest tool-specific injury rates were associated with use of jointer-planers (4.9 injuries per 1000 person-hours of use), chisels/ gouges (3.3 injuries), and drill presses (3.1 injuries). One third reported tool use-associated injuries that were severe enough to require professional medical attention; 5% of all respondents suffered partial amputations. Courses in the safe use of shop tools may help to reduce rates of injuries among woodworkers.

  14. Shear Strengthening of RC Beams Using Sprayed Glass Fiber Reinforced Polymer

    Directory of Open Access Journals (Sweden)

    Sayed Mohamad Soleimani

    2012-01-01

    Full Text Available The effectiveness of externally bonded sprayed glass fiber reinforced polymer (Sprayed GFRP in shear strengthening of RC beams under quasi-static loading is investigated. Different techniques were utilized to enhance the bond between concrete and Sprayed GFRP, involving the use of through bolts and nuts paired with concrete surface preparation through sandblasting and through the use of a pneumatic chisel prior to Sprayed GFRP application. It was found that roughening the concrete surface using a pneumatic chisel and using through bolts and nuts were the most effective techniques. Also, Sprayed GFRP applied on 3 sides (U-shaped was found to be more effective than 2-sided Sprayed GFRP in shear strengthening. Sprayed GFRP increased the shear load-carrying capacity and energy absorption capacities of RC beams. It was found that the load-carrying capacity of strengthened RC beams was related to an effective strain of applied Sprayed GFRP. This strain was related to Sprayed GFRP configuration and the technique used to enhance the concrete-FRP bond. Finally, an equation was proposed to calculate the contribution of Sprayed GFRP in the shear strength of an RC beam.

  15. Investigations On The Influence Of Process Parameters On Damage Factor During Drilling Of Glass Fiber Reinforced Composites

    Directory of Open Access Journals (Sweden)

    R.Raja

    2011-11-01

    Full Text Available Drilling is an essential operation during the assembly of the structural frames of automobiles and aircrafts made of fiber reinforced composites. The life of a joint, especially the fatigue life depends on the quality of the hole drilled. A hole with minimum damage factor can bring forth better life and aesthetic to the joint formed. The present investigation aims at arriving at a set of cutting parameters and compositional parameters to minimize damage factor during drilling of glass fiber reinforced composites. Thespindle speed was varied at three levels namely 142, 210 and 450 RPM .The chisel angles were kept at 90,100 and110 degrees and three orientations were selected for the glass fibers namely 90 degrees, 45 degrees and random orientation. A nine run experiment was designed based on Taguchi’s technique and the experiments were carried out with five replications. It was observed that a spindle speed of 450 RPM, a chisel angle of 110 degrees and a random fiber orientation can bring forth better holes with minimum damage factor .Confirmatoryexperiments were conducted to check the validity of the predictions .The experimental results matched well with the predictions

  16. Quantification of Soil Physical Properties by Using X-Ray Computerized Tomography (CT) and Standard Laboratory (STD) Methods

    Energy Technology Data Exchange (ETDEWEB)

    Maria Ambert Sanchez

    2003-12-12

    The implementation of x-ray computerized tomography (CT) on agricultural soils has been used in this research to quantify soil physical properties to be compared with standard laboratory (STD) methods. The overall research objective was to more accurately quantify soil physical properties for long-term management systems. Two field studies were conducted at Iowa State University's Northeast Research and Demonstration Farm near Nashua, IA using two different soil management strategies. The first field study was conducted in 1999 using continuous corn crop rotation for soil under chisel plow with no-till treatments. The second study was conducted in 2001 and on soybean crop rotation for the same soil but under chisel plow and no-till practices with wheel track and no-wheel track compaction treatments induced by a tractor-manure wagon. In addition, saturated hydraulic (K{sub s}) conductivity and the convection-dispersion (CDE) model were also applied using long-term soil management systems only during 2001. The results obtained for the 1999 field study revealed no significant differences between treatments and laboratory methods, but significant differences were found at deeper depths of the soil column for tillage treatments. The results for standard laboratory procedure versus CT method showed significant differences at deeper depths for the chisel plow treatment and at the second lower depth for no-till treatment for both laboratory methods. The macroporosity distribution experiment showed significant differences at the two lower depths between tillage practices. Bulk density and percent porosity had significant differences at the two lower depths of the soil column. The results obtained for the 2001 field study showed no significant differences between tillage practices and compaction practices for both laboratory methods, but significant differences between tillage practices with wheel track and no-wheel compaction treatments were found along the soil

  17. Mecanismos de abertura do sulco e adubação nitrogenada no cultivo do feijoeiro em sistema plantio direto Furrows opening mechanism for nitrogen fertilizer application in common bean crop under no-tillage

    Directory of Open Access Journals (Sweden)

    Orivaldo Arf

    2008-01-01

    Full Text Available Algumas culturas têm pouca adaptação ao sistema plantio direto, em vista da maior compactação da camada superficial do solo e, nesse caso, o mecanismo utilizado na semeadora para a abertura dos sulcos para deposição do fertilizante pode ter grande importância no sentido de facilitar a penetração das raízes. Este experimento foi desenvolvido em Selvíria (MS, com o objetivo de avaliar a produtividade do feijão de inverno cultivado em sistema plantio direto, em função da utilização de mecanismos de abertura para distribuição de fertilizantes na semeadura e da adubação nitrogenada em cobertura. O delineamento experimental utilizado foi em blocos casualizados, utilizando-se esquema fatorial 2 x 6, constituído por mecanismos de distribuição de fertilizante (haste escarificadora e disco duplo e doses de N em cobertura (0, 25, 50, 75, 100 e 125 kg ha-1, com quatro repetições. Recomenda-se o uso da haste escarificadora como mecanismo de distribuição do fertilizante, para o cultivo do feijoeiro de inverno. A adubação nitrogenada em cobertura proporciona incrementos à produtividade do feijoeiro de inverno.Some crops have shown no adaptation to no-tillage system as a function of compaction soil superficial layer. In way, the mechanism used in seeder to open furrows for deposition of fertilizer can have great importance to facilitate the penetration of roots. This experiment was carried in Selvíria (MS, with the objective to evaluate the winter common bean crop yield under no-tillage system, as function of fertilizer distribution opening mechanisms in sowing (chisel and coulter blade and sidedressing nitrogen application (0, 25, 50, 75, 100 and 125 kg ha-1. The experimental design was a randomized block, arranged in a 2 x 6 factorial scheme, constituted by fertilizer distribution opening mechanisms in sowing (chisel and coulter blade and sidedressing nitrogen doses (0, 25, 50, 75, 100 and 125 kg ha-1, with four replications

  18. Quantification of forces required for stabbing with screwdrivers and other blunter instruments.

    Science.gov (United States)

    Parmar, Kiran; Hainsworth, Sarah Victoria; Rutty, Guy Nathan

    2012-01-01

    In the UK, stabbing is the most common cause of homicide. The weapons used include knives, swords, screwdrivers and glass shards. Quantifying the exact force used in a stabbing incident is considered to be a difficult area due to the large number of variables present, such as sharpness of weapon, angle of attack and relative movements of the people involved. Having quantifiable data would allow a forensic pathologist to make a more informed decision when it comes to answering the commonly posed question in court "what was the degree of force involved in the stabbing incident?" The answer to this question is considered significant in determining an alleged assailant's intent to cause harm. This paper presents results of the first detailed study relating geometry of screwdrivers to the forces required for penetration. Additionally, a range of other blunt weapons such as pens and chisels have also been studied. A silicone rubber-foam analogue has been used as the main skin simulant owing to it having similar mechanical properties to that of human skin and giving highly repeatable results. Different screwdrivers of varying shape and size have been tested (i.e. slotted, Phillips, posidriv and Torx), along with other implements including chisels and pens. The weapon geometry was characterised and related to the peak force required for penetration. Our results show that there is a direct correlation between the cross-sectional area of a screwdriver head and the amount of force required for penetration. Screwdrivers with larger cross-sectional areas require a significantly greater force to penetrate (forces in the region of 100-120 N) but "sharper" slotted screwdrivers penetrate with much lower forces (~30 N). The forces required for penetrating the rubber-foam analogue with screwdrivers are higher than for "sharp" knives, but in some cases similar to the forces required for stabbing with "blunt" knives. For the other weapons such as chisels and biros, the force required

  19. Balanço de nutrientes em povoamento de Eucalyptus saligna implantado sobre Cambissolo Háplico no RS Nutrient balance in plantation of Eucalyptus saligna planted on Inceptisol in Rio Grande do Sul

    Directory of Open Access Journals (Sweden)

    Michael Mazurana

    2011-09-01

    Full Text Available A fragilidade de um sistema florestal pode ser avaliada através do balanço de nutrientes, destacando a eficiência da ciclagem sendo que, em certos casos, a adubação deve ser utilizada para manter ou elevar a produtividade do sistema. Objetivou-se com este estudo avaliar o comportamento de diferentes sistemas de preparo de solo em Cambissolo Háplico e sua influência nas perdas de nutrientes transportados por erosão em área cultivada com Eucalyptus saligna. Os tratamentos foram constituídos por quatro métodos de preparo do solo: subsolagem interrompida com resíduo (SIR, subsolagem contínua com resíduo (SCR, subsolagem contínua sem resíduo (SSR e coveamento mecânico (CME, em delineamento de blocos ao acaso com três repetições por tratamento. O sistema SSR apresentou as maiores perdas de nutrientes quando comparadas com as dos outros métodos de preparo de solo. As maiores perdas de nutrientes pela erosão hídrica foram, pela ordem, K > Ca > Mg > P > Cu > B. Os sistemas de preparo SIR e SSR apresentaram os maiores teores de nutrientes contidos na parte aérea e o menor balanço nutricional, respectivamente.The forest system fragility can be evaluated through nutrient balance, with an emphasis in the cycling efficiency to maintain or elevate of productivity of system. The objective of this study was to evaluate the effects of different soil tillage systems on nutrient losses transported by erosion on an Inceptisol with Eucalyptus saligna. Four tillage systems were tested: interrupted deep chiseling with residue (SIR, continuous deep chiseling with residue (SCR, continuous deep chiseling without residue (SSR and mechanical pitting (CME. The SIR system showed the greatest nutrient losses. The loss of nutrients was higher by water erosion, in the following order, K > Ca > Mg > P > Cu > B. SIR and SSR tillage systems had the highest levels of nutrients in shoots and lower nutritional balance, respectively.

  20. Endotoxins in surgical instruments of hip arthroplasty

    Directory of Open Access Journals (Sweden)

    Vania Regina Goveia

    2016-06-01

    Full Text Available Abstract OBJECTIVE To investigate endotoxins in sterilized surgical instruments used in hip arthroplasties. METHOD A descriptive exploratory study conducted in a public teaching hospital. Six types of surgical instruments were selected, namely: acetabulum rasp, femoral rasp, femoral head remover, chisel box, flexible bone reamer and femoral head test. The selection was based on the analysis of the difficulty in removing bone and blood residues during cleaning. The sample was made up of 60 surgical instruments, which were tested for endotoxins in three different stages. The EndosafeTM Gel-Clot LAL (Limulus Amebocyte Lysate method was used. RESULT There was consistent gel formation with positive analysis in eight instruments, corresponding to 13.3%, being four femoral rasps and four bone reamers. CONCLUSION Endotoxins in quantity ≥0.125 UE/mL were detected in 13.3% of the instruments tested.

  1. The Role of Stomatal Traits and Epicuticular Wax in Resistance to Mycosphaerella fijiensis in Banana and Plantain (Musa spp.

    Directory of Open Access Journals (Sweden)

    Craenen, K.

    1997-01-01

    Full Text Available Three soil tillage practices - summer ploughing, autumn ploughing and chisel - have been evaluated through their effect on soil physical characteristics and on water content during three months after wheat seeding. A comparison was made with no-tillage. This experiment has been conducted on a shallow calcareous clay soil during the season 1995-96. Primary field preparation allows a porous layer up to 20 cm depth which reduces bulk density and penetration resistance. All the profiles generated by the tillage implements were uniformed by the rain effect. The water content and distribution in the profile was significantly affected by the tillage implements. No-tillage allows the best distribution of water in the profile which is the most suitable to seed germination and plant stand. The increasing porosity due to the autumn tillage action reduced the amount of water stored in the soil in comparison with the no-tillage case.

  2. Study on comprehensive properties of duplex austenitic surfacing alloys for impacting abrasion

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, comprehensive property crack resistance, work hardening and abrasion resistance of a series of double-phases austenitic alloys(FAW) has been studied by means of SEM, TEM and type MD-10 impacting wear test machine. FAW alloys are of middle chromium and low manganese, including Fe-Cr-Mo-C alloy,Fe-Cr-Mn-C alloy and Fe-Cr-Mn-Ni-C alloy, that are designed for working in condition of impacting abrasion resistance hardfacing.Study results show that the work hardening mechanism of FAW alloys are mainly deformation high dislocation density and dynamic carbide aging, the form of wearing is plastic chisel cutting. Adjusting the amount of carbon, nickel, manganese and other elements in austenitic phase area, the FAW alloy could fit different engineering conditions of high impacting, high temperature and so on.

  3. Produtividade de soja e milho após coberturas de inverno e descompactação mecânica do solo Soybean and corn yield after soil winter covers and soil mechanical loosening

    Directory of Open Access Journals (Sweden)

    Henrique Debiasi

    2010-06-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de coberturas de inverno e da descompactação mecânica do solo sobre o desempenho de soja e milho, em sistema de plantio direto. Foram conduzidos dois experimentos em Eldorado do Sul, RS, sobre Argissolo Vermelho compactado, nas safras 2005/2006 e 2006/2007. No primeiro, o delineamento experimental foi em blocos ao acaso, com parcelas subdivididas. Os tratamentos consistiram de duas profundidades teóricas de atuação da haste sulcadora da semeadora (0,06 e 0,12 m, subparcela e de três tipos de coberturas do solo no inverno (parcela: pousio, aveia-preta (Avena strigosa e aveia-preta+ervilhaca (Vicia Sativa. Em 2006, a cobertura aveia-preta+ervilhaca foi substituída por nabo-forrageiro (Raphanus sativus. No segundo experimento, realizado em blocos ao acaso, o solo foi escarificado e os tratamentos consistiram do uso de aveia-preta ou nabo-forrageiro como cobertura de inverno. Os cultivos de cobertura reduziram a compactação superficial do solo (0-0,06 m em comparação ao pousio e, na safra 2006/2007, sob condições de baixa disponibilidade hídrica, proporcionaram maior produtividade de milho e soja. Isso não se repetiu em 2006/2007, quando a disponibilidade hídrica foi adequada. O aumento da profundidade de atuação das hastes sulcadoras não influenciou a produtividade da soja e do milho. A escarificação reduziu a produtividade da soja e do milho em relação ao SPD contínuo.The objective of this work was to evaluate the effect of soil winter covers and soil mechanical loosening on soybean and corn yield, in no-tillage system. Two experiments were carried oud in Rio Grande do Sul state, Brazil, in a compacted Argissolo Vermelho (Haplic Acrisol, in the 2005/2006 and 2006/2007 crop seasons. The first experiment was carried out in a complete block design, with a split plot arrangement. The treatments were two theoretical working depths of a driller chisel-type furrow opener (0.06 and 0

  4. Soap-stone in architecture of North European cities. A nomination as a candidate for a Global Heritage Stones Resource

    Science.gov (United States)

    Bulakh, Andrey

    2016-04-01

    Soap stone represents soft Proterozoic rock type from the deposit Nunnalahti situated on the western shore of the big Lake Pielinen in Eastern Finland. It consists of talc (40 - 50 %), magnesite MgCO3 (40 - 50 %), chlorite (5 - 8 %), dolomite, calcite, etc. The colour of the stone is very spectacular and varies from yellow and brownish-yellow to grey, greenish grey. The soft stone is a highly workable material for a sculptor's chisel. It was one of the most popular ornamental rocks used architecture of the Modern style in St Petersburg, Helsinki, Turku, Tampere and other North European cities lately in the XIX-th centuries. Examples are given and discussed. References: Bulakh, A.G., Abakumova, N.B., and Romanovsky, J.V. St Petersburg: a History in Stone. 2010. Print House of St Petersburg State University. 173 p. (In English).

  5. Respuesta del girasol a diferentes profundidades de incorporación del fertilizante Response of sunflower to deep fertilization

    Directory of Open Access Journals (Sweden)

    Peña C. Jorge

    1989-12-01

    Full Text Available El estudio se realizó con el objetivo de analizar la respuesta del girasol a la fertilización a diferentes profundidades. Los tratamientos fueron: incorporación del fertilizante a 10 cm con rastrillo pulidor, a 15 cm con rastra-arado, a 25 cm con arado de discos y a 30 cm con cincel-abonador; testigo absoluto sin fertilizar. Se presentaron incrementos en rendimiento a la incorporación del fertilizante a 30 cm, mostrando diferencias altamente significativas con la fertilización a 10 cm y el testigo, los incrementos en rendimiento fueron de 64.9% y 109.7% en promedio para cada uno de los semestres. Igualmente, se observaron aumentos en el diámetro del capítulo, en el peso de 1.000 semillas, en la altura de planta y disminución en el porcentaje de semillas vanas en el capitulo. Los porcentajes de cáscara, almendra, aceite y proteína no respondieron a la fertilización profunda. Desde el punto de vista económico, la mejor alternativa correspondió a la fertilización a 30 cm con cincel-abonador; la incorporación a 15 cm, con la rastra-arado, se presentó como según da opción con una tasa de retorno marginal aceptable, la cual para la región se estimó en 100 % como valor mínimo.The objective of the study was to analize the response in yield and other agronomic characteristics of sunflower based on different depths of fertilizer application. The treatments were application of fertilizer 10 cm depth tandem disk harrow, 15 cm depth with disk harrow, 25 cm depth with disk plow and 30 cm depth with chisel; an absolut control was also included. The incorporation with chisel was significantly higher than disk harrow and the control, but not with tandem disk harrow and disk plow. Increments of the chisel treatment with respect to disk harrow for the two consecutive semester were thus: for yield 64.9% and 109.7%; for capitulum diameter 20.1% and 29.9%: for weight of 1.000 seeds 34.7% and 37.1 % for plant height 15.6 % and 27.7 %, and a

  6. Trial Excavation at the Xujiafen Site in Xiaogan City,Hubei%湖北孝感市徐家坟遗址试掘

    Institute of Scientific and Technical Information of China (English)

    孝感市博物馆

    2001-01-01

    This site lies to the west of Xujiawan, Guiqiao village, Xiaogan city, Hubei province,and occupies a total area of 30,000 sq m. The remains belong to the Neolithic and early Shang cultures.The former category includes an ash-pit and artifacts of the pottery ding tripod, vat-shaped object, jar,urn, plate, bowl, dou stemmed vessel, cup, vessel cover and spindle whorl, and the stone axe, adze,chisel and arrowhead. The latter comprises the pottery jar, large-mouthed zun vase, urn, plate, dou and vat-shaped object. According to the characteristic features of the objects, the Neolithic group of remains should be assigned to the Shijiahe culture, while the early Shang group must have directly developed from cultural complexes in the Central Plains as some of its objects are similar to those from Hubei Huangpi Panlongcheng and some resemble those from Erlitou and upper Erligang.

  7. A balsa violin

    Science.gov (United States)

    Waltham, Chris

    2009-01-01

    Almost half a century ago John Schelleng determined the scaling rules that show how violins can be made from nontraditional materials. These principles suggest that balsa wood may be a possible, if unlikely, construction material. To test this idea, a balsa violin was constructed and found to be playable. Its vibrational behavior is shown to be in agreement with Schelleng's scaling rules. The instrument was not difficult to build, and its construction can be repeated by anyone of moderate skill with a chisel and sandpaper and access to an audio frequency analysis program. The reward is a tactile appreciation for the vibrational behavior of materials and the physics of musical instruments that is difficult to gain otherwise.

  8. Evaluation of the agricultural tractor using biofuel and diesel oil; Avaliacao de um trator agricola utilizando biocombustivel e oleo diesel

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Reny Adilmar Prestes; Pinheiro Neto, Raimundo; Meyer, Wagner; Mendonca, Elton Costa de; Roberti, Marcelo [Universidade Estadual de Maringa (UEM), PR (Brazil)], Emails: raplopes@uem.br, rpneto@uem.br

    2009-07-01

    Test with alternative fuels is essential to evaluate the performance of machines and engines. In this paper, the performance of a tractor in chiseling operation was evaluated using oil diesel and biofuel (oil diesel + soybean vegetable oil mixture). Speed of displacement, slip wheels, force traction bar and fuel consumption was evaluated in areas under tillage and no-tillage. The speed of displacement of the set presented similar behavior in tillage and no-tillage. Bigger values mean force in the bar of traction, slip and fuel consumptions had been observed for no-tillage with the tractor operating with diesel. Bigger values mean consumption the biofuel had been observed in areas under tillage. The coverings of the soil had influenced in the values of force bar traction, slip wheels, speed of displacement and fuel consumption. In the studied conditions, the tests demonstrate that the mixture oil diesel + soybean vegetable oil had not influenced in the performance of the tractor. (author)

  9. THE INFLUENCE OF MINIMUM TILLAGE SYSTEMS UPON THE SOIL PROPERTIES, YIELD AND ENERGY EFFICIENCY IN SOME ARABLE CROPS

    Directory of Open Access Journals (Sweden)

    Teodor RUSU

    2006-05-01

    Full Text Available The paper presents the influence of the conventional ploughing tillage technology in comparison with the minimum tillage, upon the soil properties, weed control, yield and energy efficiency in the case of maize (Zea mays L., soyabean (Glycine hispida L. and winter wheat (Triticum aestivum L. in a three years crop rotation. For all cultures within the crop rotation, the weed encroachment is maximum for the disc harrow and rotary harrow soil tillage, followed by the chisel and paraplow. The weed encroachment is minimum for the conventional ploughing tillage technology. The results of investigations showed that the yield is a conclusion soil tillage systems influence on soil properties, plant density assurance and on weed control.

  10. Managing an oil spill response

    International Nuclear Information System (INIS)

    In the oil spill response business everything starts with a plan. When planning is set at only middle and top management levels before being chiseled into corporate marble, the result is all too often a plan for failure. For any chance at success, the plan must make sense to, and solve the problems of, the people at the ''business'' end of the business. In the case of Marine Spill Response Corporation (MSRC), that means highly trained responders are put at sea or along coastlines to remove oil from the water, or to deflect oil away from environmentally sensitive areas. They are fortunate in MSRC, and especially in the Gulf Coast Region, to have on their staff, some of the most knowledgeable and experienced oil spill responders in the world. The company relies on them to help build their plans, and to poke holes wherever their plans are inconsistent with getting the job done right

  11. Sculpture and Life. The Relation Between Form of Sculpture and Musical Character in the Sound Stone by Pinuccio Sciola

    Directory of Open Access Journals (Sweden)

    Rita Ladogana

    2015-07-01

    Full Text Available The paper describes the most significant results that the Sardinian sculptor Pinuccio Sciola has reached in a lot of years with diligence and artistic research.From the big monoliths to the seeds of peace, until the surprising discovery of lithophones, the path reveals complex results that contemplate, with particular insistence in production of latter years, a close connection between sculpture, music and architecture. From when Sciola discovers that the large blocks of basalt and of limestone, which he always treated with the chisel or the emery disc, supervise soul music, the creative act focuses only in a researches about a perfect summary of sculptural object with a clear aesthetic value and acoustic sound-sculpting potential. The voice of matter emanates extraordinary sounds conditioned, beyond that the action of the artist, by the interaction with elements of nature, with atmospheric elements, with all reality that surrounds them.

  12. The Impact of Various Types of Tillage on the Soil Water Availability

    Directory of Open Access Journals (Sweden)

    BESNIK GJONGECAJ

    2014-07-01

    Full Text Available The present study is focused on the role that various ways of soil tillage may have on the increase of soil water availability to the plant roots. The research was carried out in Tirana, Albania, and the experiment was established in a vineyard field. The soil was cultivated in three different ways (three treatments: conventional (plowing plus surface cultivation, conservative (subsoiling plus surface cultivation, conservative (chisel plowing plus surface cultivation. In order to quantify the available soil water to plants, the pF-soil moisture curves were determined. The determined pF-soil moisture curves belong to two layers: 0-25 cm and 25-50 cm, taken into consideration for each treatment. The soil water content between the field capacity (FWC and the permanent wilting point (PWP was considered as potentially available to plant roots. The results showed clearly that the way the tillage was applied has a significant effect on soil water capacity potentially available to plant roots. Loosening the soil by breaking up the impermeable layers, the conservative tillage makes possible the increase of the amount of water held by soil particles in the range between FWC and PWP, in comparison with the conventional tillage. This increase of available soil water capacity is due to the soil loosening in deeper layers of soil profile as well, which leads to the situation where the plant roots can penetrate deeper and occupy more space, consequently, drawing more water to meet their needs. Within the conservative tillage versions, sub soiling seems to be more effective in the increase of available soil water capacity comparing with the chisel plowing. The study contributes, as well, to the determination of the pF-soil moisture curves in a way that is theoretically well based. The founded curves fit with the exponential form of functions and the coefficients of determinations, for each case under study, are significant in high probability levels.

  13. Comparison of the Effects of No Tillage, Minimum Tillage and Conventional Tillage on Dry Land Wheat Yield in Pebbly Field in Tropical Region

    Directory of Open Access Journals (Sweden)

    N Loveimi

    2016-04-01

    Full Text Available The current study was conducted to compare different tillage methods on wheat yield in pebbly dry land areas done within three years (2006-2008 in north Khouzestan (Baghmalek city in randomized block design with five treatments and four replications. The experimental treatments were:(1chisel plow +seed-drill, (2Semi plow(mold board plow with remove mold board+seed-drill, (3no-till-drill, (4sweep plow +seed-drill and (5conventional method(mold board plow+ broadcasting seed and fertilizer+ sweep plow. These treatments included minimum tillage (treatments 1, 2 and 4, no tillage (treatment 3 and conventional tillage (treatment 5. Complex variance analyses of three years data showed that there was no significant difference between tillage methods and interaction of tillage methods with year in soil moisture content in different plant growth stages (stem, flowering, and filling seeds stages but years were different in this factor. Variance analyses of data showed that there was no significant difference between different tillage methods in percent of organic materials in different soil depths in the end of the project. However, no difference in tillage methods in the amount of organic material has been analyzed based on the pebbly conditions. The complex variance analyses of data also showed that tillage methods had significant effect on grain yield and other agronomical factors, except plant height and harvest index. According to the results any devices cause to back more gravel and cobblestone into sub soil layer provide more grain yield. Therefore, mold board plow resulted in maximum yield in three experimental years which were different in amount and distribution of rainfall, and also in third year the amount of rainfall was considerably low. The grain yield averages of three years were 1333, 1558, 1190, 1080 and 1787 Kg.ha-1 for chisel plow, semi plow, no-till-drill, sweep plow and mold board plow respectively.

  14. Control of Tylenchulus semipenetrans on Citrus With Aldicarb, Oxamyl, and DBCP.

    Science.gov (United States)

    Timmer, L W; French, J V

    1979-10-01

    Soil application of DBCP (l,2-dibromo-3-chloropropane) and foliar applications of oxamyl (methyl N',N'-dimethyl-N-[(methylcarbamoyl)oxy]-l-thiooxamimidate) were compared for control of Tylenchulus semipenetrans in a grapefruit (Citrus paradisi) orchard, DBCP reduced nematode populations and increased fruit growth rate, fruit size at harvest, and yield compared to the untreated controls in the 2 years following treatments. Foliar applications of oxamyl reduced nematode populations and increased fruit growth rate slightly the first year, but not in the second. Foliar applications of oxamyl did not improve control attained by DBCP alone. Soil application of aldicarb [2-methyl-2-(methylthio)propionaldehyde-O-(methylcarbamoyl)oxime] or DBCP to an orange (C. sinensis) orchard reduced T. semipenetrans populations in the 3 years tested and increased yield in 1 of 3 years. Aldicarb treatment reduced fruit damage caused by the citrus rust mite, Phyllocoptruta oleivora. Aldicarb, applied at 5.7 or 11.4 kg/ha, by disk incorporation or chisel injection, was equally effective in controlling nematodes, improving yields, fruit size, and external quality. In a grapefruit orchard, chisel-applied aldicarb reduced nematode populations and rust mite damage and increased yields in both years and increased fruit size in one year. The 11.4-kg/ha rate was slightly more effective than the 5.7-kg/ha rate. Aldicarb appears to be an adequate substitute for DBCP for nematode control in Texas citrus orchards and well-suited to an overall pest management system for Texas citrus.

  15. Control of Tylenchulus semipenetrans on Citrus With Aldicarb, Oxamyl, and DBCP.

    Science.gov (United States)

    Timmer, L W; French, J V

    1979-10-01

    Soil application of DBCP (l,2-dibromo-3-chloropropane) and foliar applications of oxamyl (methyl N',N'-dimethyl-N-[(methylcarbamoyl)oxy]-l-thiooxamimidate) were compared for control of Tylenchulus semipenetrans in a grapefruit (Citrus paradisi) orchard, DBCP reduced nematode populations and increased fruit growth rate, fruit size at harvest, and yield compared to the untreated controls in the 2 years following treatments. Foliar applications of oxamyl reduced nematode populations and increased fruit growth rate slightly the first year, but not in the second. Foliar applications of oxamyl did not improve control attained by DBCP alone. Soil application of aldicarb [2-methyl-2-(methylthio)propionaldehyde-O-(methylcarbamoyl)oxime] or DBCP to an orange (C. sinensis) orchard reduced T. semipenetrans populations in the 3 years tested and increased yield in 1 of 3 years. Aldicarb treatment reduced fruit damage caused by the citrus rust mite, Phyllocoptruta oleivora. Aldicarb, applied at 5.7 or 11.4 kg/ha, by disk incorporation or chisel injection, was equally effective in controlling nematodes, improving yields, fruit size, and external quality. In a grapefruit orchard, chisel-applied aldicarb reduced nematode populations and rust mite damage and increased yields in both years and increased fruit size in one year. The 11.4-kg/ha rate was slightly more effective than the 5.7-kg/ha rate. Aldicarb appears to be an adequate substitute for DBCP for nematode control in Texas citrus orchards and well-suited to an overall pest management system for Texas citrus. PMID:19300660

  16. EFFECTS OF DIFFERENT SOIL TILLAGE SYSTEMS ON YIELD OF MAIZE, WINTER WHEAT AND SOYBEAN ON ALBIC LUVISOL IN NORTH-WEST SLAVONIA

    Directory of Open Access Journals (Sweden)

    Silvio KOŠUTIĆ

    2006-05-01

    Full Text Available The paper presents comparison of three soil tillage systems in maize, winter wheat and soybean growing on anthropogenic Albic Luvisol in north-west Slavonia, Croatia, during 1996-1999. Tillage systems and implements were: 1. conventional system (CT-plough, disc-harrow and combined implement, 2. conservation system (RT-chisel plough and multitiller, 3. no-till system (NT. The aim of testing was comparison of different tillage systems energy requirement and its influence on yield. Results indicate that conventional tillage (CT system was the greatest energy consumer with 1813.10 MJ ha-1. Comparing to conventional tillage (CT system, conservation (RT system with chisel plough and multitiller spent 1133.14 MJ ha-1or 37.5 % less, while no-till (NT system required even 85.1 % less energy or 270.13 MJ ha-1. In the first season the greatest yield of maize, 7.78 Mg ha-1, achieved conventional tillage (CT system while next to it was conservation (RT system with 7.77 Mg ha-1. No-till (NT system achieved 7.56 Mg ha-1. Second season the greatest yield of winter wheat, 5.89 Mg ha-1, achieved conservation tillage (RT system. Next to it was conventional (CT system with 5.75 Mg ha-1, while no-till (NT achieved 5.73 Mg ha-1. Third season the greatest yield of soybean, 2.71 t ha-1, achieved conservation tillage (RT system again, while next to it was conventional (CT system with 2.64 Mg ha-1. No-till (NT achieved 2.61 Mg ha-1.

  17. An economic analysis of clubmoss control with mechanical treatments in Saskatchewan rangeland, Canada%机械措施控制加拿大萨斯克彻温草场丛生卷柏生长的经济分析

    Institute of Scientific and Technical Information of China (English)

    彭鸿嘉; Bob Redmann; 傅伯杰; 陈利顶

    2004-01-01

    Clubmoss (Selaginella densa Rybd.) is a low. dense-matted, slow-growing perennial plant, which occupies large areas of the Northern Great Plains and is common on Saskatchewan rangelands. It rarely exceeds 2. 5 cm in height and has an extensive mat of very fine roots penetrating to a depth of about 8 cm. The mat intercepts precipitation and holds it on the surface of the ground. Much of this moisture dose not penetrate this layer of mat and is unavailable to more desirable vegetation. The most common habitats for clubmoss growing are level areas and moderate slopes in plain topography. The plant prefers well developed soil of medium textured and nearly neutral reaction. Knowledge of the ecological role of clubmoss is limited. However, it dominates some native grassland stands, but has no forage value and increases with overgrazing and mismanagement of prairie pasture. The objective of this study was to complete an economic analysis of pitting and chisel plowing mechanical treatments that are commonly used to reduce clubmoss on rangelands in the Northern Great Plains. Cost and benefit analysis of pitting and chisel plowing were determined for the sandy on loamy range sites in the Dry and Moist Brown Soil Zones, and the Dark Brown Soil Zone in Saskatchewan. The levels of costs and benefits per hectare from mechanical range renovation depend upon the additional animal units (AU) raised and return to grazing per AU and the carrying capacity. Additional AU could reached on areas receiving each of the two treatments on loamy and sandy range sites in the three selected areas in Saskatchewan. Economic feasibility of treatment varies and a number of factors affect the final results, but weather is more important in determining forage productivity than mechanical disturbance. This study shows that net present values for chisel plowing were negative, indicating this treatment is not economically feasible on any range site at either 8% or 10% interest rate. Results for pitting

  18. Qualidade física do solo na produtividade da cultura do feijoeiro num Argissolo Soil physical quality on black beans yield in an Alfisol

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    Gilberto Loguércio Collares

    2006-11-01

    Full Text Available O objetivo deste trabalho foi determinar as propriedades físicas e o intervalo hídrico ótimo (IHO de um Argissolo, sob diferentes estados de compactação, cultivado com feijoeiro. Foram utilizados três experimentos, cujos tratamentos constituíram-se de: plantio direto (PD; plantio direto compactado pelo tráfego de quatro passadas de máquina (PDc; e escarificação em área anteriormente sob plantio direto (Esc. Avaliaram-se a densidade, a porosidade, a umidade volumétrica e a resistência à penetração do solo. Nas plantas, avaliaram-se a distribuição do sistema radicular e a produtividade. A densidade crítica obtida pelo IHO foi de 1,75 Mg m-3. No PDc a densidade do solo foi superior à crítica na maioria das camadas, enquanto o PD e Esc apresentaram densidade acima da crítica em poucas camadas. A umidade do solo ficou fora dos limites do IHO na maior parte do ciclo da cultura. A resistência à penetração ficou acima da crítica no PDc em todas as avaliações. O sistema radicular concentrou-se superficialmente no PDc com melhor distribuição e desenvolvimento no PD e Esc. Nos três experimentos, a produtividade do Esc foi de 2 a 12% menor, e a do PDc foi de 30 a 62% menor do que no PD. A escarificação não foi necessária para as condições físicas do PD.In this work, soil properties and least limiting water range (LLWR were determined for an Alfisol under three states of compaction with black beans crop. Three experiments were used, comprising the following treatments: 12 years of no-tillage - NT; 12 years, of no-tillage compacted by four passes of a bucket loader - NTc; and chiseling of soil previously under no-tillage for 12 years - Ch. Throughout the plant cycle, bulk density, total porosity, volumetric water content, air filled porosity and soil resistance to penetration were evaluated. Plant root distribution and yield were also evaluated. The critical bulk density obtained by LLWR was 1.75 Mg m-3. In the NTc the

  19. Water erosion during a 17-year period under two crop rotations in four soil management systems on a Southbrazilian Inceptisol

    Science.gov (United States)

    Bertol, Ildegardis; Vidal Vázquez, Eva; Paz Ferreiro, Jorge

    2010-05-01

    Soil erosion still remains a persistent issue in the world, and this in spite of the efforts to ameliorate soil management systems taken into account the point of view of environmental protection against soil losses. In South Brazil water erosion is mainly associated to rainfall events with a great volume and high intensity, which are more or less evenly distributed all over the year. Nowadays, direct drilling is the most widely soil management system used for the main crops of the region. However, some crops still are grown on conventionally tilled soils, which means mainly ploughing and harrowing and less frequently chisel ploughing. In Lages-Santa Catarina State, Brazil, a plot experiment under natural rain was started in 1992 on an Inceptisol with the aim of quantifying soil and water losses. Treatments included bare and vegetated plots. The crop succession was: oats (Avena strigosa), soybean (Glycine max), vetch (Vicia sativa), maize (Zea mays), fodder radish (Raphanus sativus) and beans (Phaseolus vulgaris). Soil tillage systems investigated in this study were: i) conventional tillage (CT), ii) reduced tillage (MT), iii) no tillage (NT) under crop rotation and iv) conventional tillage on bare soil (BS). Treatments CT and BS involved ploughing plus twice harrowing, whereas MT involved chisel ploughing plus harrowing. Rainfall erosivity from January 1 1992 to December 31 2009 was calculated. Soil losses from the BS treatment along the 17 year study period were higher than 1200 Mg ha-1. Crop cover significantly reduced erosion, so that under some crops soil losses in the CT treatment were 80% lower than in the BS treatment. In turn soil losses in the MT treatment, where tillage was performed by chiselling and harrowing, were on average about 50% lower than in the CT treatment. No tillage was the most efficient soil management system in reducing soil erosion, so that soil losses in the NT treatment were about 98% lower than in the BS treatment. The three

  20. Seasonal dynamics of CO2 efflux in soils amended with composted and thermally-dried sludge as affected by soil tillage systems in a semi-arid agroecosystem

    Science.gov (United States)

    García-Gil, Juan Carlos; Soler-Rovira, Pedro; López-de-Sa, Esther G.; Polo, Alfredo

    2014-05-01

    In semi-arid agricultural soils, seasonal dynamic of soil CO2 efflux (SCE) is highly variable. Based on soil respiration measurements the effects of different management systems (moldboard plowing, chisel and no-tillage) and the application of composted sludge (CS) and thermally-dried sewage sludge (TSS) was investigated in a long-term field experiment (28 years) conducted on a sandy-loam soil at the experimental station 'La Higueruela' (40o 03'N, 4o 24'W). Both organic amendments were applied at a rate of 30 Mg ha-1 prior to tillage practices. Unamended soils were used as control for each tillage system. SCE was moderate in late spring (2.2-11.8 μmol CO2 m-2 s-1) when amendments were applied and tillage was performed, markedly decreased in summer (0.4-3.2 μmol CO2 m-2 s-1), following a moderate increase in autumn (3.4-14.1 μmol CO2 m-2 s-1), rising sharply in October (5.6-39.8 μmol CO2 m-2 s-1 ). In winter, SCE was low (0.6-6.5 μmol CO2 m-2 s-1). In general, SCE was greater in chisel and moldboard tilled soils, and in CS and particularly TSS-amended soils, due to the addition of labile C with these amendments, meanwhile no-tillage soils exhibited smaller increases in C efflux throughout the seasons. Soil temperature controlled the seasonal variations of SCE. In summer, when drought occurs, a general decrease of SCE was observed due to a deficit in soil water content. After drought period SCE jumped to high values in response to rain events ('Birch effect') that changed soil moisture conditions. Soil drying in summer and rewetting in autumn may promotes some changes on the structure of soil microbial community, affecting associated metabolic processes, and enhancing a rapid mineralization of water-soluble organic C compounds and/or dead microbial biomass that acts as an energy source for soil microorganisms. To assess the effects of tillage and amendments on SCE, Q10 values were calculated. Data were grouped into three groups according to soil moisture (0

  1. Soil Carbon Changes in Transitional Grain Crop Production Systems in South Dakota

    Science.gov (United States)

    Woodard, H. J.

    2004-12-01

    Corn-C (Zea Mays L.), soybean-S (Glycine max L.) and spring wheat-W (Triticum aestivum L.) crops were seeded as a component of either a C-S, S-W, or C-S-W crop rotation on silt-loam textured soils ranging from 3.0-5.0% organic matter. Conservation tillage(chisel plow-field cultivator) was applied to half of the plots. The other plots were direct seeded as a no-till (zero-tillage) treatment. Grain yield and surface crop residues were weighed from each treatment plot. Crop residue (stover and straw) was removed from half of the plots. After four years, soil samples were removed at various increments of depth and soil organic carbon (C) and nitrogen (N) was measured. The ranking of crop residue weights occurred by the order corn>>soybean>wheat. Surface residue accumulation was also greatest with residue treatments that were returned to the plots, those rotations in which maize was a component, and those without tillage. Mean soil organic carbon levels in the 0-7.5cm depth decreased from 3.41% to 3.19% (- 0.22%) with conventional tillage (chisel plow/field cultivator) as compared to a decrease from 3.19% to 3.05% (-0.14%) in plots without tillage over a four year period. Organic carbon in the 0-7.5cm depth decreased from 3.21% to 3.01% (- 0.20%) after residue removed as compared to a decrease from 3.39% to 3.23% (-0.17%) in plots without tillage applied after four years. The soil C:N ratio (0-7.5cm) decreased from 10.63 to 10.37 (-0.26 (unitless)) in the tilled plots over a four-year period. Soil C:N ratio at the 0-7.5cm depth decreased from 10.72 to 10.04 (-0.68) in the no-till plots over a four year period. Differences in the soil C:N ratio comparing residue removed and residue returned were similar (-0.51 vs. -0.43 respectively). These soils are highly buffered for organic carbon changes. Many cropping cycles are required to determine how soil carbon storage is significantly impacted by production systems.

  2. Strength Properties and Organic Carbon of Soils in the North Apalachian Region

    Energy Technology Data Exchange (ETDEWEB)

    Blanco-Canqui, H; Lal, Rattan; Owen, L B.; Post, W M.; Izaurralde, R Cesar C.

    2005-04-01

    Soil strength influenced by management and soil properties controls plant growth, root development, and soil-moisture relations. The impact of textural and structural parameters on soil strength is moderated by soil organic C (SOC) concentration. Therefore, the objectives of this study were to assess differences in soil strength and SOC concentration in watersheds under long-term (>15 yr) management practices in the North Appalachian region on a predominantly Typic Hapludults on undulating slopes (>6% slope). Seven watersheds without field replication under moldboard plow (MP), chisel plow, disk with beef cattle manure (DiskM), no-till with beef cattle manure (NTm), no-till with no beef cattle manure (NTnm), pasture, and forest were studied. Cone index (CI), shear strength, bulk density (b), volumetric moisture content (v), and SOC concentration were determined at the summit, backslope, and footslope landscape positions at the 0- to 10-, 10- to 20-, and 20- to 30-cm depths. The SOC concentration was slightly higher at the footslope than at the summit position in the cultivated watersheds. The b was lower at the footslope than at the summit in NTm (1.22 vs. 1.42 Mg m{sup -3}) and chisel (1.34 vs. 1.47 Mg m{sup -3}) treatments. Forest had the lowest CI (0.19 MPa), shear strength (6.11 kPa), and b (0.93 Mg m{sup -3}) and the highest SOC concentration (62.7 g kg{sup -1}), whereas MP had the highest CI (0.67 MPa), shear strength (25.5 kPa), b (1.44 Mg m{sup -3}), and the lowest SOC concentration (13.6 g kg{sup -1}) in the 0- to 10-cm depth (P < 0.01). The SOC concentration in NTm was 1.7 times higher than that in NTnm, and both no-till treatments had lower b (<1.21 Mg m{sup -3}) than MP (1.44 Mg m{sup -3}) at 0- to 10-cm depth (P < 0.01). Manuring decreased both CI and shear strength, but increased SOC concentration. The b, v, and SOC concentration were potential predictors of CI; whereas b and SOC concentration were of shear strength (r2 > 0.42; P < 0.01). Results show

  3. Seeding quality and soybean yields from using different furrowers and operation speedsQualidade de semeadura e produtividade da soja sob diferentes sulcadores e velocidades de operação

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    Alcir José Modolo

    2012-12-01

    Full Text Available The sowing process for annual no-till crops affects the physical soil conditions around the seeds by exposing them to adverse conditions that may limit initial plant development and reduce potential yield. The use of seed drills that are not compatible with field conditions and the use of inappropriate seed drill speeds affect sowing performance. Therefore, this study aims to evaluate the effect of different seed drill types and operating speeds on soybean quality parameters and yield components. Two furrow opener (double disc and chisel and four operating speed (0.86; 1.22; 1.47 and 1.94 m s-1 treatments were used. The following variables were evaluated: mean number of days until emergence, plant distribution uniformity, sowing depth, area of the soil disturbed, crop stand and grain yield. Overall, the chisel furrow opener provided a greater sowing depth and increased the disturbed soil area more than the double disc furrow opener. Increased operating speeds reduced crop stands and yields and increased the disturbed soil area. Em culturas anuais submetidas ao sistema plantio direto o processo de semeadura afeta o condicionamento físico do solo ao redor das sementes expondo as mesmas a condições adversas, podendo limitar o desenvolvimento inicial das plantas e minimizar o potencial produtivo. O uso de sulcadores não condizentes com a situação de campo e de velocidades inadequadas são fatores que afetam o bom desempenho da semeadura. Nesse contexto, este trabalho teve por objetivo, avaliar o efeito de diferentes sulcadores e velocidades de operação sobre parâmetros de qualidade de semeadura e componentes de produtividade da cultura da soja. Os tratamentos foram compostos pela combinação entre dois sulcadores (disco e haste e quatro velocidades de operação (0,86; 1,22; 1,47 e 1,94 m s-1. Foram avaliados: o número médio de dias para a emergência, a uniformidade de distribuição de plantas, a profundidade de semeadura, a área de

  4. Carbon supply and storage in tilled and nontilled soils as influenced by cover crops and nitrogen fertilization.

    Science.gov (United States)

    Sainju, Upendra M; Singh, Bharat P; Whitehead, Wayne F; Wang, Shirley

    2006-01-01

    Soil carbon (C) sequestration in tilled and nontilled areas can be influenced by crop management practices due to differences in plant C inputs and their rate of mineralization. We examined the influence of four cover crops {legume [hairy vetch (Vicia villosa Roth)], nonlegume [rye (Secale cereale L.)], biculture of legume and nonlegume (vetch and rye), and no cover crops (or winter weeds)} and three nitrogen (N) fertilization rates (0, 60 to 65, and 120 to 130 kg N ha(-1)) on C inputs from cover crops, cotton (Gossypium hirsutum L.), and sorghum [Sorghum bicolor (L.) Moench)], and soil organic carbon (SOC) at the 0- to 120-cm depth in tilled and nontilled areas. A field experiment was conducted on Dothan sandy loam (fine-loamy, siliceous, thermic Plinthic Paleudults) from 1999 to 2002 in central Georgia. Total C inputs to the soil from cover crops, cotton, and sorghum from 2000 to 2002 ranged from 6.8 to 22.8 Mg ha(-1). The SOC at 0 to 10 cm fluctuated with C input from October 1999 to November 2002 and was greater from cover crops than from weeds in no-tilled plots. In contrast, SOC values at 10 to 30 cm in no-tilled and at 0 to 60 cm in chisel-tilled plots were greater for biculture than for weeds. As a result, C at 0 to 30 cm was sequestered at rates of 267, 33, -133, and -967 kg C ha(-1) yr(-1) for biculture, rye, vetch, and weeds, respectively, in the no-tilled plot. In strip-tilled and chisel-tilled plots, SOC at 0 to 30 cm decreased at rates of 233 to 1233 kg C ha(-1) yr(-1). The SOC at 0 to 30 cm increased more in cover crops with 120 to 130 kg N ha(-1) yr(-1) than in weeds with 0 kg N ha(-1) yr(-1), regardless of tillage. In the subtropical humid region of the southeastern United States, cover crops and N fertilization can increase the amount of C input and storage in tilled and nontilled soils, and hairy vetch and rye biculture was more effective in sequestering C than monocultures or no cover crop.

  5. Influence of Reduced Tillage and Green Manures on Weeds in Organic Farming

    Directory of Open Access Journals (Sweden)

    Grosse, Meike

    2014-02-01

    Full Text Available Reduced tillage and green manures may be capable to further improve organic crop production systems, if they are adapted to the specific needs of organic farming. One goal of the European research project TILMAN ORG (www.tilman-org.net is to develop a more efficient weed management with at the same time increased biodiversity through improved use of green manures in different systems of reduced tillage. The results of a repeated one year trial on “Domaene Frankenhausen”, the research farm of University of Kassel, regarding the effect of both leguminous and non-leguminous green manures on weeds in four different tillage systems is the main topic of this paper. After the green manure species Sinapis alba, Trifolium resupinatum and Vicia sativa and a bare fallow as a control the main crop oat was sown in four different tillage systems: plough, chisel (2012 respectively disc harrow (2013, mulching + drilling and direct drilling. 2012 weed cover was generally low in the plough system compared to the other tillage systems. In the mulching + drilling- and direct drilling- systems the plots after the green manure species S. alba and T. resupinatum and the bare fallow had to be given up because weed pressure was too high. Compared to that V. sativa was able to suppress weeds considerably better and resulted in similar yields to the plough and chisel treatments 2012 on a level from 55.3 dt ha-1 to 59.1 dt ha-1. 201all mulching + drilling- and direct drillingplots had to be given up because of too high weed pressure. The weed pressure in the disc harrow – system differed not significantly from the plough system, but only green manure species Vicia sativa resulted in similar oat yields compared to the plough treatments (V. sativa x disc harrow 56.2 dt ha-1, V. sativa x plough 53.9 dt ha-1. In the plough – treatments there was an overall low weed pressure. Concerning yield there were no significant differences regarding green manure treatment.

  6. A preliminary study on 3D reconstruction and extracting mandibular first molar by dint of high-speed air turbine handpiece based on rapid prototyping%数控拔牙技术的实验研究

    Institute of Scientific and Technical Information of China (English)

    刘小明; 李健俫; 王建民; 张志光; 陈隆福; 陈贵丰; 黄湘穗

    2012-01-01

    目的 探讨牙颌数字化三维重建技术与快速成型技术、数控技术相结合,实现微创和自动化拔牙的可行性.方法 锥形束CT(cone beam computed tomography,CBCT)扫描下颌牙颌标本,获得数据.采用Mimics软件重建牙颌三维实体模型,Magics软件进行数据修补.选取左侧下颌第一磨牙三维立体数据,快速成型软件切片、UG软件数据转换,导入自行研制的数控拔牙机,严格坐标定位后磨除左侧下颌第一磨牙.结果 建立了良好的三维牙颌模型,用数控拔牙机成功磨除左侧下颌第一磨牙.结论 牙颌数字化三维重建技术与快速成型技术、数控技术相结合,应用于数控拔牙机拔除标本牙是可行的.%Objective A new technique combined with digital dental teeth, 3D reconstruction from cone beam computed tomography ( CBCT) data and rapid prototyping is presented, in order to solve the difficulties of tooth extracting by traditional chisel. Methods Software Mimics and Magics were used to reconstruct three dimensional model from CT image scanned by DCTPRo CBCT with 0.2 mm slice thickness. The achievement can be applied to accomplish tooth extracting by high-speed air turbine handpiece based on rapid prototyping. Results Mandibular first molar was extracted by dint of high-speed air turbine handpiece based on rapid prototyping. Conclusion The new technique combined with digital dental teeth and rapid prototyping can be used to solve the difficulties of the tooth extracting by traditional chisel.

  7. Desenvolvimento e testes de uma semeadora-adubadora modular para pequenas propriedades rurais Development and test of a modular seeder - fertilizer for small countryside properties

    Directory of Open Access Journals (Sweden)

    Lucas Arend

    2005-12-01

    Full Text Available O trabalho apresenta o desenvolvimento e testes de campo de equipamento agrícola modular. Para o desenvolvimento do equipamento, foi utilizada metodologia de projeto para sistemas modulares. O objetivo principal foi desenvolver um sistema modular que contribuísse para melhorar o atual quadro de mecanização agrícola da pequena propriedade rural, enfocando alguns dos equipamentos destinados às atividades conservacionistas de cultivo. Por ser modular, o equipamento atende às funções de semear-adubar, escarificar e sulcar o solo. Para a função semear-adubar, podem ser usados cinzéis e disco duplo para a semeadura; já para as funções de escarificação e sulcagem, podem ser usadas ferramentas específicas, facilmente intercambiadas em um chassi tubular principal. Os resultados para solo argiloso (Typic Oxisols, com umidade em torno de 20,5% e massa seca de 11,5 t ha-1 para a variante semeadora-adubadora com duplo cinzel, foram satisfatórios com relação aos parâmetros de patinagem das rodas motoras, regularidade de distribuição em profundidade, cobertura das sementes, distribuição longitudinal das sementes e emergência de plantas.This work presents the development and field tests of a modular agricultural implement. A Modular Design Product methodology was used for the implement development, and the main objective was the development of a modular system to improve the actual situation of mechanization on small countryside properties. The development focus was kept on some implements for conservative cultivation. For its modularity, the implement developed attained the functions of seeding - fertilizing, scarification and furrowing the soil. For the function of seeding-fertilizing can be used either narrow chisels or double disc, for the furrowing function a specific tool can be used. The main tubular chassis allowed an easily interchangeability between both functions (seed-season and furrow-season. The results for Typical

  8. Dryland soil water storage susceptibility to different soil tillage practices under Vetch- Wheat crop rotation

    Directory of Open Access Journals (Sweden)

    Jallil Asghari Meydani

    2014-12-01

    Full Text Available Crop rotation and soil tillage are two practices which would result in better use of water resources. So in order to investigate the effects of different crop rotation and soil tillage practices on soil water storage, a multi-annual experiment employing two crop rotations and six tillage practices was carried out in dry-land condition of Maragheh, northwest of Iran during year 2007 till 2011. Results showed that autumn cultivation of the common vetch (CR1 compared to spring cultivation of the common vetch (CR2 left more water in the soil for the following wheat cropping in the next years and subsequently increased biological and grain yield of wheat. It was also notified that the increase of water storage in second sampling depth (15-30 cm was significantly more than two other depths (0-15 and 30-45 cm. Results also depicted that the tillage practice applying "chisel plough + cyclo-tiller + seed drill (TP1" compared to other practices and especially the routine tillage of the region moldboard plow + disk harrow + manual seed broadcasting, TP5 significantly increased soil water storage. The mentioned tillage practice (TP1 markedly decreased the bulk density of soil and increased biological and grain yield of wheat, as well. Therefore, applying TP1 tillage practice beside autumn cultivation of common vetch in rotation with wheat would be a good strategy to increase soil water storage and crop yield in dry-land conditions.

  9. Weed infestation in canopy of spring barley in condition of different tillage systems and fertilization and plant protection levels

    Directory of Open Access Journals (Sweden)

    Piotr Kraska

    2012-12-01

    Full Text Available The purpose of this work was to determine the influence of conventional tillage (fall ploughing at 25 cm and minimum tillage systems (chisel ploughing at 30 cm and two differentiated fertilization and plant protection levels on number, species composition and air dry weed mass in spring barley cv. Rataj. This spring barley was cultivated in crop rotation potato - spring barley - winter rye. The analysis of field infestation was made prior to spring barley harvest with quantitative- weighting method. There was estimated number of weeds, weed species composition and air dry weight of weeds in two randomly chosen areas of each plot of 0.5 m2. The density of weeds and weed air dry weight was statistically analysed by means of variance analysis, and the mean values were estimated with Tukey's confidence intervals (p=0.05. Intensive level of fertilization and chemical crop protection decreased number of monocotyledonous weeds and total weeds in canopy of spring barley. Conventional system of soil cultivation decreased in a canopy of spring barley the following species of weeds: Geranium pusillum, Galinsoga parviflora, Stellaria media, Apera spica-venti, Poa annua and Echinochloa crusgalli. Conventional tillage increases number of Chamomilla suaveolens and Fallopia convolvulus in a canopy of spring barley. Intensive fertilization and plant protection levels decreased weed infestation first of all through Echinochloa crusgalli, Apera spica-venti, Fallopia convolvulus, Galinsoga parviflora, Geranium pusillum, Chenopodium album and Setaria pumila.

  10. Culture-independent methods to study subaerial biofilm growing on biodeteriorated surfaces of stone cultural heritage and frescoes.

    Science.gov (United States)

    Cappitelli, Francesca; Villa, Federica; Polo, Andrea

    2014-01-01

    Actinobacteria, cyanobacteria, algae, and fungi form subaerial biofilm (SAB) that can lead to material deterioration on artistic stone and frescoes. In studying SAB on cultural heritage surfaces, a general approach is to combine microscopy observations and molecular analyses. Sampling of biofilm is performed using specific adhesive tape and sampling of SAB and the substrate with sterile scalpels and chisels. Biofilm observations are carried out using optical and scanning electron microscopy. Specific taxa and EPS in biofilm can be readily visualized by fluorochrome staining and subsequent observation using fluorescence or confocal laser scanning microscopy. The observation of cross sections containing both SAB and the substrate shows if biofilm has developed not only on the surface but also underneath. Following nucleic acid extraction, 16S rRNA gene sequencing is used to identify bacterial taxa, while 18S rRNA gene and internal transcribed spacer (ITS) sequence analysis is used to study eukaryotic groups. In this chapter, we illustrate the protocols related to fluorescence in situ hybridization (FISH), scanning electron microscopy (SEM), and denaturing gradient gel electrophoresis (DGGE).

  11. Energy Demand And Corn Yield With Fertilizer Application Before Sowing In Two Soil Tillage Systems; Demanda energetica e produtividade da cultura do milho com adubacao de pre-semeadura em dois sistemas de manejo do solo

    Energy Technology Data Exchange (ETDEWEB)

    Bertolini, Erick Vinicius [Universidade Estadual Paulista (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Pos-Graduacao em Agronomia], E-mail: erickbertolini@yahoo.com.br; Gamero, Carlos Antonio [Universidade Estadual Paulista (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Dept. de Engenharia Rural], E-mail: gamero@fca.unesp.br

    2010-07-01

    This study was conducted to evaluate the corn yield with fertilizer application before sowing and provide of the energy demand results involved in the fertilizer application before sowing and sowing in two soil tillage systems. The experiment was carried out at Faculdade de Ciencias Agronomicas (FCA), Universidade Estadual Paulista (UNESP), Botucatu-SP campus, from November 2006 to April 2007, in a Dystric Nitosol. The experimental design was in randomized blocks with split-plots and four repetitions. The main plots consisted in two soil tillage systems (no-tillage and reduced tillage with chisel plow) and the split-plots of fertilizer application methods (surface fertilizer application before corn sowing and fertilizer application conventional). Obtained results were analyzed by Tukey test at 5% of probability for comparing averages. Statistical analysis showed that fertilizer application before corn sowing the soil tillage systems did not influence the traction force, bar power demanded, effective field capacity, demanded time, energy specific consumption and hourly fuel consumption; the reduced tillage showed higher area fuel consumption. For corn sowing it was observed that no-tillage system showed lower traction force, bar power demanded, energy specific consumption, hourly and area consumption of fuel. Fertilizer application before corn sowing did not affect corn yield in relation to the fertilizer application conventional. (author)

  12. Identification of Gene Modules Associated with Low Temperatures Response in Bambara Groundnut by Network-Based Analysis.

    Science.gov (United States)

    Bonthala, Venkata Suresh; Mayes, Katie; Moreton, Joanna; Blythe, Martin; Wright, Victoria; May, Sean Tobias; Massawe, Festo; Mayes, Sean; Twycross, Jamie

    2016-01-01

    Bambara groundnut (Vigna subterranea (L.) Verdc.) is an African legume and is a promising underutilized crop with good seed nutritional values. Low temperature stress in a number of African countries at night, such as Botswana, can effect the growth and development of bambara groundnut, leading to losses in potential crop yield. Therefore, in this study we developed a computational pipeline to identify and analyze the genes and gene modules associated with low temperature stress responses in bambara groundnut using the cross-species microarray technique (as bambara groundnut has no microarray chip) coupled with network-based analysis. Analyses of the bambara groundnut transcriptome using cross-species gene expression data resulted in the identification of 375 and 659 differentially expressed genes (pHeuristic Cluster Chiseling Algorithm resulted in 6 and 7 gene modules in sub-optimal and very sub-optimal temperature stresses being identified, respectively. Modules of sub-optimal temperature stress are principally enriched with carbohydrate and lipid metabolic processes, while most of the modules of very sub-optimal temperature stress are significantly enriched with responses to stimuli and various metabolic processes. Several transcription factors (from MYB, NAC, WRKY, WHIRLY & GATA classes) that may regulate the downstream genes involved in response to stimulus in order for the plant to withstand very sub-optimal temperature stress were highlighted. The identified gene modules could be useful in breeding for low-temperature stress tolerant bambara groundnut varieties. PMID:26859686

  13. 成都市郫县三观村遗址发掘简报

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Sanguan Village Site is an archaeological site with the double strata of Baodun Culture and Shi'erqiao Culture as the main remains. The remains of Baodun Culture were ash pits, ash ditches, burials, house foundations, pebble mounds, etc., and the artifacts were pottery jars with flower-petal-shaped rim, high-necked jars, zun-vessels and stone adzes, chisels and spearheads, etc. the date of which was Phase I of Baodun Culture. The remains of Shi'erqiao Culture were ash pits, ash ditches, kilns, hearths, burials, etc. and the artifacts were pottery jars with small flat bottom, jars with restricted mouth, short-necked jars, gui-vessels,jugs and cups with pointed bottom, the date of which was the later stage of Phase I of Shi' erqiao Culture. The discovery and excavation of this site provided new data for the in-depth researches on Baodun and Shi'erqiao Cultures, especially the house foundations and burials were rare materials for the researches on the lifestyles and funeral customs of the residents on Chengdu Plain in the pre-Qin period.%三观村遗址位于成都市郫县红光镇三观村六组,西北距郫县城区约5.8公里,东南距金沙遗址约13.6公里。

  14. The Ash Pit H9 at Miaodigou Site in Sanmenxia City,Henan%河南三门峡市庙底沟遗址仰韶文化H9发掘简报

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In May 2002,Henan Provincial Institute of Cultural Relics and Archaeology conducted rescue excavation to Miaodigou Site,one of the important discoveries of which was an ash pit numbered H9.It had regular structure and yielded rich artifacts,most of which were potteries,plus stone implements and animal bones,etc.Over 100 complete or restorable pottery wares were found,including painted basins,bowls,jars,pots,fine clay basins,pointed-bottomed bottles,flat-bottomed bottles,zeng-steamers,vats,sandy jars,vessel lids,cups,fu-cauldrons,stoves,ding-tripods,jugs and so on,as well as ornaments like pottery rings.The stone implements were axes,shovels,spindle whorls,chisels,hammers and grinders,etc.The discoveries in H9 are significantly meaningful for the researches on Miaodigou Type Culture and scientifically valuable for the exploration to the natures of this type of remains.%庙底沟遗址位于河南省三门峡市西南部的湖滨区韩庄村,2001年被公布为全国重点文物保护单位。遗址位于流人黄河的青龙涧河和苍龙涧河之间的黄土塬上,处于青龙涧河下游左岸二级阶地的前缘(图一)。

  15. Comparative assessment of water infiltration of soils under different tillage systems in eastern Botswana

    Science.gov (United States)

    Moroke, T. S.; Dikinya, O.; Patrick, C.

    Water infiltration is an important component of water balance for improving crop production potential in dryland soil tillage systems in Botswana, particularly in the eastern region. Hardsetting soils common in arable lands of Botswana, often require some kind of tillage such as mouldboard ploughing, chiselling and ripping to improve waterharvesting and crop growth conditions. The objective of this study was to compare ponded cumulative infiltration, steady state infiltration rate and sorptivity of soils cultivated using deep ripping, single and double mouldboard ploughing. This study was conducted on Chromic Luvisols (sandy loam), Haplic Luvisols (sandy clay loam), Ferric Luvisols (clay loam), and Ferric Arenosols (sand). Infiltration was measured using double ring infiltrometer method for 4 h. Although infiltration was smaller on traffic line of deep ripping system at all sites, it was only significantly ( P 0.05) different under deep ripped. Cumulative and steady state infiltration rate was greater under sandy than loamy soils, smaller under double ploughing compared with single ploughed and deep ripped soils. Sorptivity was not significantly ( P > 0.05) different among tillage systems but was greater under sandy than sandy loam soils. Information on tillage and infiltration can improve implementation of waterharvesting technologies and crop production in Botswana.

  16. Transnational pharmaceutical corporations and neo-liberal business ethics in India.

    Science.gov (United States)

    D'Mello, Bernard

    2002-03-01

    The author critiques the expedient application of market valuation principles by the transnational corporations and other large firms in the Indian pharmaceutical industry on a number of issues like patents, pricing, irrational drugs, clinical trials, etc. He contends that ethics in business is chiseled and etched within the confines of particular social structures of accumulation. An ascendant neo-liberal social structure of accumulation has basically shaped these firms' sharp opposition to the Indian Patents Act, 1970, government administered pricing, etc. The author contents that the practice of neo-liberal economics is strongly associated with a "one-dimensional" ethics that privileges market valuation principles over all others. This seems to inevitably generate a social counter-movement that struggles for social protections. He critiques neo-liberal business practices from a perspective that derives from the work of the economic anthropologist Karl Polanyi. Before the present phase of liberalization in India, markets were "managed", but without a "welfare state" in place. Moving toward deregulation of the markets without a welfare state in place is unethical. Keeping the debilities of the institutional framework of public policy in mind, the author adopts a Polanyian perspective that places its trust and hope in the growing social legitimacy of the counter-movement in opposition to both neo-liberal business practices and the degenerate behavior of state agencies.

  17. NANOROBOTICS IN ADVANCES IN PHARMACEUTICAL SCIENCES

    Directory of Open Access Journals (Sweden)

    DEEPA R. PARMAR

    2010-06-01

    Full Text Available Nanorobotics is the technology of creating machines or robots at or close to the scale of a nanometre (10-9 metres, machines constructed at the molecular level (nanomachines may be used to cure the human body of its various ills. This application of nanotechnology to the field of medicine is commonly called as nanomedicine.Nanotechnology promises futuristic applications such as microscopic robots that assemble other machines or travel inside the body to deliver drugs or do microsurgery. Taking inspiration from the biological motors of living cells, chemists are learning how to utilize protein dynamics to power microsize and nanosize machines with catalytic reactions. Nanorobot?s toolkit contains features like medicine cavity containing medicine, probes, knives and chisels to remove blockages and plaque, microwave emitters and ultrasonic signal generators to destroy cancerous cells, two electrodes generating an electric current, heating the cell up until it dies, powerful lasers could burn away harmful material like arterial plaque.To cure skin diseases, a cream containing nanorobots may be used which remove the right amount of dead skin, remove excess oils, add missing oils, apply the right amounts of natural moisturising compounds, and even achieve the elusive goal of ’deep pore cleaning’.other fields of applications are to clean the wounds,to break the kidney stones, to treat gout, for parasite removal, for cancer treatment, treatment of arteriosclerosis.

  18. Corn stover harvest increases herbicide movement to subsurface drains: RZWQM simulations

    Science.gov (United States)

    Shipitalo, Martin J.; Malone, Robert W.; Ma, Liwang; Nolan, Bernard T.; Kanwar, Rameshwar S.; Shaner, Dale L.; Pederson, Carl H.

    2016-01-01

    BACKGROUND Crop residue removal for bioenergy production can alter soil hydrologic properties and the movement of agrochemicals to subsurface drains. The Root Zone Water Quality Model (RZWQM), previously calibrated using measured flow and atrazine concentrations in drainage from a 0.4 ha chisel-tilled plot, was used to investigate effects of 50 and 100% corn (Zea mays L.) stover harvest and the accompanying reductions in soil crust hydraulic conductivity and total macroporosity on transport of atrazine, metolachlor, and metolachlor oxanilic acid (OXA). RESULTS The model accurately simulated field-measured metolachlor transport in drainage. A 3-yr simulation indicated that 50% residue removal decreased subsurface drainage by 31% and increased atrazine and metolachlor transport in drainage 4 to 5-fold when surface crust conductivity and macroporosity were reduced by 25%. Based on its measured sorption coefficient, ~ 2-fold reductions in OXA losses were simulated with residue removal. CONCLUSION RZWQM indicated that if corn stover harvest reduces crust conductivity and soil macroporosity, losses of atrazine and metolachlor in subsurface drainage will increase due to reduced sorption related to more water moving through fewer macropores. Losses of the metolachlor degradation product OXA will decrease due to the more rapid movement of the parent compound into the soil.

  19. X-Ray Fluorescence and Laser-Induced Breakdown Spectroscopy analysis of Roman silver denarii

    Energy Technology Data Exchange (ETDEWEB)

    Pardini, L. [Istituto di Chimica dei Composti Organometallici del CNR, Research Area of Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy); El Hassan, A. [National Institute for Laser- Enhanced Sciences (NILES), Cairo University Giza (Egypt); Ferretti, M. [Istituto per le Tecnologie Applicate ai Beni Culturali, Area della Ricerca del CNR di Montelibretti Roma (Italy); Foresta, A.; Legnaioli, S.; Lorenzetti, G. [Istituto di Chimica dei Composti Organometallici del CNR, Research Area of Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy); Nebbia, E. [Universita degli Studi di Torino (Italy); Catalli, F. [Monetiere di Firenze, Museo Archeologico Nazionale Firenze (Italy); Harith, M.A. [National Institute for Laser- Enhanced Sciences (NILES), Cairo University Giza (Egypt); Diaz Pace, D. [Institute of Physics ' Arroyo Seco' , Faculty of Science, Tandil (Argentina); Anabitarte Garcia, F. [Photonics Engineering Group, University of Cantabria, Santander (Spain); Scuotto, M. [Dipartimento di Scienze Archeologiche, Via Galvani 1, 56126 Pisa (Italy); Palleschi, V., E-mail: vincenzo.palleschi@cnr.it [Istituto di Chimica dei Composti Organometallici del CNR, Research Area of Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy); Dipartimento di Scienze Archeologiche, Via Galvani 1, 56126 Pisa (Italy)

    2012-08-15

    In this paper we present the results of a study performed on a large collection of silver Roman republican denarii, encompassing about two centuries of history. The joint use of Laser-Induced Breakdown Spectroscopy (LIBS) and X-Ray Fluorescence (XRF) spectroscopy allowed for an accurate determination of the coins' elemental composition; the measurements, performed mostly in situ at the 'Monetiere' in Florence, revealed a striking connection between the 'quality' of the silver alloy and some crucial contemporary events. This finding was used to classify a group of denarii whose dating was otherwise impossible. The comparison with other contemporary denarii disproves a recent theory on the origin of the so called 'serrated' denarii (denarii showing notched chisel marks on the edge of the coin). - Highlights: Black-Right-Pointing-Pointer We studied a large collection of Roman republican silver denarii. Black-Right-Pointing-Pointer XRF and LIBS allowed to determine the precious metal content of the coins. Black-Right-Pointing-Pointer A correlation of the 'quality' of the alloy with some contemporary events was found. Black-Right-Pointing-Pointer The study allowed to controvert a recent theory on the so called 'serrated' denarii.

  20. In-situ XRF and LIBS analysis of roman silver denarii

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, A. El; Harith, M.A. [National Institute for Laser- Enhanced Science (NILES), Cairo University, Giza (Egypt); Ferretti, M. [Istituto per le Tecnologie Applicate ai Beni Culturali, Area della Ricerca del CNR di Montelibretti, Roma (Italy); Foresta, A.; Legnaioli, S.; Lorenzetti, G.; Palleschi, V.; Pardini, L., E-mail: incenzo.palleschi@cnr.it [Istituto di Chimica dei Composti Organometallici del CNR. Area della Ricerca del CNR di Pisa (Italy); Nebbia, E. [Universita degli Studi di Torino (Italy); Catalli, F. [Monetiere di Firenze, Museo Archeologico Nazionale, Firenze (Italy)

    2011-07-01

    Full text: In this paper we present the result of a study performed on a large collection of silver roman republican denarii, encompassing about two centuries of history. The joint use of Laser-Induced Breakdown Spectroscopy (LIBS) and X-Ray Fluorescence (XRF) spectroscopy allowed for an accurate determination of the coins' elemental composition; the measurements, performed mostly in situ at the 'Monetiere' in Florence, revealed a striking correlation of the 'quality' of the silver alloy with some crucial contemporary events. This finding was used for classifying a group of denarii whose dating was otherwise impossible. The results reported demonstrate the possibility of analyzing in short time and in situ a statistically significant number of coins. Useful information can be obtained about the coin composition, both for main components and traces that could be used for classifying the coins in groups, according to different levels of concentrations of the detected elements. The comparison with other contemporary denarii allowed also to controvert a recent theory on the origin of the so called 'serrated' denarii (denarii showing notched chisel marks on the edge of the coin). (author)

  1. Qualidade física de um latossolo vermelho sob plantio direto submetido à descompactação mecânica e biológica Physical quality of untilled oxisol subjected to mechanical and biological decompaction

    Directory of Open Access Journals (Sweden)

    Sérgio Damaso da Silveira Junior

    2012-12-01

    Full Text Available A escarificação e o uso de plantas de cobertura de inverno têm sido adotados para promover a melhoria dos atributos físicos do solo relacionados à aeração. O objetivo deste trabalho foi verificar o efeito das plantas de cobertura de inverno e escarificação nas propriedades físicas de um Latossolo Vermelho distrófico, textura argilosa, após 16 anos em sistema plantio direto. Os tratamentos foram realizados em maio de 2009 e consistiram de: plantio direto (PD, plantio direto com escarificação mecânica a 0,25 m (PD-E e plantio direto com descompactação biológica por meio da cultura do nabo forrageiro (PD-B. O delineamento experimental foi em blocos ao acaso com quatro repetições, totalizando 12 unidades experimentais. Dezoito meses após a aplicação dos tratamentos, foram coletadas amostras indeformadas de solo em cada unidade experimental, em cinco camadas: 0,0-0,1; 0,1-0,2; 0,2-0,3; 0,3-0,4; e 0,4-0,5 m. Foram avaliados os atributos físicos do solo: porosidade, densidade do solo (Ds, permeabilidade ao ar (Ka e índices de continuidade de poros. A Ka foi medida por meio de um permeâmetro de carga constante de ar em nove potenciais mátricos (ψm: -0,5; -1; -2; -3; -5; -7; -10; -50; e -100 kPa. Os resultados indicam que os atributos físicos do solo avaliados não foram alterados pelo uso de plantas de cobertura e escarificação. Por outro lado, houve diferenças entre camadas de solo, principalmente entre 0,0-0,1 e 0,1-0,2 m. Na camada de 0,1-0,2 m, a Ds foi maior e a porosidade total e Ka (ψm = -5 kPa foram menores do que na camada de 0,0-0,1 m. No PD-E, verificou-se que a macroporosidade foi maior na camada de 0,0-0,1 m em comparação com os outros tratamentos. Os resultados sugerem que o solo estudado submetido aos tratamentos de descompactação, após 18 meses, retornou a valores semelhantes aos da testemunha.Chiseling and winter cover crops have been adopted to improve the soil physical properties related to

  2. Laser Scanning of a Monolithic Column during Processing in Middle Egypt

    Science.gov (United States)

    Ajioka, O.; Hori, Y.

    2011-09-01

    From ancient quarries around Akoris in Middle Egypt, which belong to the Ptolemaic and Roman periods, the stone blocks could be carried to the working area located in the outside of the city. Those blocks included a giant monolithic column measured approximately 14m in length, which had been cracked for reasons unknown and must have contributed to disuse of monolith. The first deal is a comparison of plans drawn by the point clouds by laser scanning with those coming from plane-tabling, which had been one of popular methods for measuring in the last century. This part shows how the laser scanning technology is useful in far better measuring and documentation of the site. The second discuss is about a detailed assessment of the procedure of processing through the observation of chisel marks and the detail analysis about the 3 dimensional data. In the result, we are succeed to show the restoration of the procedure of the proceedings using guidelines and a wooden curve since we concentrate attention on the point of abstracting the centre line and shaving the surface into the round shape.

  3. Design and scale-up of a semi-industrial downer-reactor for the rounding of irregular polymer particles

    Science.gov (United States)

    Sachs, Marius; Schmidt, Jochen; Peukert, Wolfgang; Wirth, Karl-Ernst

    2016-03-01

    The recent development of rapid prototyping technologies towards additive manufacturing reveals some major drawbacks of processes such as laser beam melting (LBM). This contribution focuses on the lack of suitable polymer material with a fine particle size and good flowability. Polymer particles obtained by a wet grinding process 1 are treated in a heated downer reactor. This treatment changes the particles' morphology from a chiselled state towards a spherical form by surface tension forces in a molten state 2 and leads to an improved flowability. To reach the required amount of rounded polymer powder, a downer reactor in semi-industrial scale has been established and will be characterized in this article. For the purpose of particle rounding it is necessary to avoid contact of molten particles with each other and with the hot reactor walls. Furthermore, the heat distribution has been investigated as one of the key parameters of the process. Finally, a proof of concept by rounding wet grinded PBT material was successfully conducted. The product was examined to obtain data about a change in particle size and flowability.

  4. Soil and crop residue CO2-C emission under tillage systems in sugarcane-producing areas of southern Brazil

    Directory of Open Access Journals (Sweden)

    Luís Gustavo Teixeira

    2013-10-01

    Full Text Available Appropriate management of agricultural crop residues could result in increases on soil organic carbon (SOC and help to mitigate gas effect. To distinguish the contributions of SOC and sugarcane (Saccharum spp. residues to the short-term CO2-C loss, we studied the influence of several tillage systems: heavy offset disk harrow (HO, chisel plow (CP, rotary tiller (RT, and sugarcane mill tiller (SM in 2008, and CP, RT, SM, moldboard (MP, and subsoiler (SUB in 2009, with and without sugarcane residues relative to no-till (NT in the sugarcane producing region of Brazil. Soil CO2-C emissions were measured daily for two weeks after tillage using portable soil respiration systems. Daily CO2-C emissions declined after tillage regardless of tillage system. In 2008, total CO2-C from SOC and/or residue decomposition was greater for RT and lowest for CP. In 2009, emission was greatest for MP and CP with residues, and smallest for NT. SOC and residue contributed 47 % and 41 %, respectively, to total CO2-C emissions. Regarding the estimated emissions from sugarcane residue and SOC decomposition within the measurement period, CO2-C factor was similar to sugarcane residue and soil organic carbon decomposition, depending on the tillage system applied. Our approach may define new emission factors that are associated to tillage operations on bare or sugarcane-residue-covered soils to estimate the total carbon loss.

  5. X-ray computed microtomography analysis of the influence of different agricultural treatments on the topsoil porosity of a Grey Brown Luvisol from Ontario

    Science.gov (United States)

    Taina, I. A.; Heck, R. J.; Scaiff, N. T.

    2009-05-01

    One of the most important applications of X-ray computed tomography (CT) for the study of soil is the characterization of the shape and spatial distribution of pores. Analysis of 3D X-ray CT image data, related to different pore categories, can provide insight to soil structural changes, which have implications in water infiltration and soil aeration, resulting from agricultural practices. The aim of this study was to evaluate changes in the spatial characteristics of voids, due to tillage practices, in the Ap horizon of an Orthic Grey- Brown Luvisol (located at the Elora Research Station of the University of Guelph). Undisturbed oriented soil samples were collected from ten plots representing different tillage treatments: spring moldboard plow, spring moldboard plow, cultivate and pack, fall moldboard plow, cultivate and pack, spring tandem disc, no cultivator, fall offset disc, fall offset disc, cultivate and pack, fall chisel plow, cultivate and pack, zero zone till (soys twin rows), zero tillage (long term), and zero tillage (corn residue removed in row, soys twin rows). Since the utilization of standardized classes, in the quantification of similar features, proved to be necessary in order to obtain comparable results, categories of pores, separated according to their size, circularity and orientation were considered in the interpretation of data. Total volume of pores and volume percentage of each class were calculated, revealing substantial differences among the analyzed soil samples.

  6. Rebeca Matte. El cuerpo de la histeria

    Directory of Open Access Journals (Sweden)

    Gloria Cortés Aliaga

    2015-12-01

    Full Text Available In 1876-77 Bourneville and Regnard published in France the album Iconographie Photographique de la Salpêtrière with studies of the psychiatrist Jean-Martin Charcot (1825-1893. The album gave account of the phases of hysteria in the most important psychiatric hospice of Paris and its images reproduced a series of postures that became an iconographical and theatrical source for a series of problematic female. Twenty-three years later, the chilean sculptress Rebeca Matte sent to the official Salon the work Horace (1899, characterized by physical and psychological rigidity that are associated with the hysterical-epileptic attacks seizures and to certain states of dementia framed in experiences of delirium, paralysis and abandonment of reason. From Horace Rebeca brings out its chisel a variety of figures and neighboring neurotic, phallic and histrionic that allow wonder on the reception of psychoanalysis and the study of hysteria in the female space. Could they be instruments of sublimation that allow experiencing the most widespread disorders of the female "madness”? Or rather tools of reporting on what psychoanalysis defined as a delimitation of "being a woman"?

  7. Effects of Tillage Management Systems on Residue Cover and Decomposition

    Institute of Scientific and Technical Information of China (English)

    ZHANGZHIGUO; XUQI; 等

    1998-01-01

    The effects of tillage methods on percent surface residue cover remaining and decomposition rates of crop residues were evaluated in this study.The line transect method was used to measure residue cover percentage on continuumous corn(Zea mays L.) plots under no tillage (NT),Conventional tillage(CT),chisel plow(CH),and disk tillage (DT).Samples of rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) were used for residue decompostion study,Results showed that the percentage of residue cover remaining was significantly higher for NT than for CH and DT and that for CT was the lowest(<10%),For the same tillage system ,the percent residue cover remaining was significantly higher in the higher fertilizer N rate treatments relative to the lower fertilizer N treatments.weight losses of rye and vetch residues followed a similar pattern under CT and DT ,and they were significantly faster in CT and DT than in NT system ,Alo ,the amounts of residue N remaining during the first 16 weeks were alway higher under NT than under CT and DT.

  8. Soil preparation and forage sowing time for crop-livestock integration in corn culture

    Directory of Open Access Journals (Sweden)

    Luiz Fernando de Andrade Fritsch

    2012-01-01

    Full Text Available This work was carried out during the 2008/2009 crop season, in an Oxisol. It was used a split-plot arrangement design, with each plot corresponding to a different soil preparation system and each split-plot corresponding to a different sowing time of the forage Brachiaria brizantha Stapf. The soil preparation systems were: heavy harrowing (HH, disk plough (DP, chisel plough (CP and no-till (NT, and the forage sowing times were: 0, 8, 16 and 25 days after sowing (DAS of corn, arranged in 16 treatments with 3 replicates. The productive and vegetative characteristics of the corn were evaluated. Soil preparations have influenced plant height and the first ear height, with the highest value found for the heavy harrow treatment. Forage sowing time had no influence on vegetative characteristics of the corn and productive characteristics were not influenced by the soil preparations. The forage sowing time had influence on corn productivity, causing decrease in competition with corn forage from 5 DAS. The productivity was highly correlated with the number of grains per ear.

  9. Mitochondrial DNA and Y-chromosomal stratification in Iran: relationship between Iran and the Arabian Peninsula.

    Science.gov (United States)

    Terreros, Maria C; Rowold, Diane J; Mirabal, Sheyla; Herrera, Rene J

    2011-03-01

    Modern day Iran is strategically located in the tri-continental corridor uniting Africa, Europe and Asia. Several ethnic groups belonging to distinct religions, speaking different languages and claiming divergent ancestries inhabit the region, generating a potentially diverse genetic reservoir. In addition, past pre-historical and historical events such as the out-of-Africa migrations, the Neolithic expansion from the Fertile Crescent, the Indo-Aryan treks from the Central Asian steppes, the westward Mongol expansions and the Muslim invasions may have chiseled their genetic fingerprints within the genealogical substrata of the Persians. On the other hand, the Iranian perimeter is bounded by the Zagros and Albrez mountain ranges, and the Dasht-e Kavir and Dash-e Lut deserts, which may have restricted gene flow from neighboring regions. By utilizing high-resolution mitochondrial DNA (mtDNA) markers and reanalyzing our previously published Y-chromosomal data, we have found a previously unexplored, genetic connection between Iranian populations and the Arabian Peninsula, likely the result of both ancient and recent gene flow. Furthermore, the regional distribution of mtDNA haplogroups J, I, U2 and U7 also provides evidence of barriers to gene flow posed by the two major Iranian deserts and the Zagros mountain range. PMID:21326310

  10. Soil physical quality changes under different management systems after 10 years in Argentinian Humid Pampa

    Science.gov (United States)

    Costa, J. L.; Aparicio, V. C.; Cerda, A.

    2014-08-01

    The Argentinian Humid Pampa extends over about 60 million ha, 90% of which are agricultural lands. The southeast of the Buenos Aires Province is part of the Humid Pampa (1 206 162 ha). The main crops are wheat, sunflower, corn and soybean. The management systems used in the area are: moldboard plow (MP), chisel plow (CP) and no-till (NT). Excessive soil cultivation under MP causes decreases in the soil organic carbon content (SOC). Adopting NT may reduce the effects of intensive agriculture, through the maintenance and accumulation of SOC. However, the soil compaction under NT causes degradation of the soil structure, reduces the soil water availability and reduces the soil hydraulic conductivity. We evaluated the evolution of the soil physical parameters in three management systems. After 10 years of experiments in four farmers' fields, we found that: soil bulk density was significantly higher under NT. The change in mean weight diameter (CMWD) of aggregates increased as the management system became more intensive. We did not find significant differences in time and management systems in hydraulic conductivity at tension (h)0 cm and h=20 cm. The reduction in total porosity under NT is mainly a product of a reduction in the percentage of mesopores in the soil. Time had no statistically significant effect on the SOC content. The management system did not affect the yields of crop. In this work, the results indicate a modification of some soil physical parameters (porosity, near-saturated hydraulic conductivity, soil structure) due to uninterrupted agricultural production.

  11. Community composition and population genetics of insect pathogenic fungi in the genus Metarhizium from soils of a long-term agricultural research system.

    Science.gov (United States)

    Kepler, Ryan M; Ugine, Todd A; Maul, Jude E; Cavigelli, Michel A; Rehner, Stephen A

    2015-08-01

    Fungi in the genus Metarhizium are insect pathogens able to function in other niches, including soil and plant rhizosphere habitats. In agroecosystems, cropping and tillage practices influence soil fungal communities with unknown effects on the distribution of Metarhizium, whose presence can reduce populations of crop pests. We report results from a selective media survey of Metarhizium in soils sampled from a long-term experimental farming project in the mid-Atlantic region. Field plots under soybean cultivation produced higher numbers of Metarhizium colony-forming units (cfu) than corn or alfalfa. Plots managed organically and via chisel-till harboured higher numbers of Metarhizium cfu than no-till plots. Sequence typing of Metarhizium isolates revealed four species, with M. robertsii and M. brunneum predominating. The M. brunneum population was essentially fixed for a single clone as determined by multilocus microsatellite genotyping. In contrast, M. robertsii was found to contain significant diversity, with the majority of isolates distributed between two principal clades. Evidence for recombination was observed only in the most abundant clade. These findings illuminate multiple levels of Metarhizium diversity that can be used to inform strategies by which soil Metarhizium populations may be manipulated to exert downward pressure on pest insects and promote plant health. PMID:25627647

  12. Predicting dredging-associated effects to coral reefs in Apra Harbor, Guam - Part 1: Sediment exposure modeling.

    Science.gov (United States)

    Gailani, Joseph Z; Lackey, Tahirih C; King, David B; Bryant, Duncan; Kim, Sung-Chan; Shafer, Deborah J

    2016-03-01

    Model studies were conducted to investigate the potential coral reef sediment exposure from dredging associated with proposed development of a deepwater wharf in Apra Harbor, Guam. The Particle Tracking Model (PTM) was applied to quantify the exposure of coral reefs to material suspended by the dredging operations at two alternative sites. Key PTM features include the flexible capability of continuous multiple releases of sediment parcels, control of parcel/substrate interaction, and the ability to efficiently track vast numbers of parcels. This flexibility has facilitated simulating the combined effects of sediment released from clamshell dredging and chiseling within Apra Harbor. Because the rate of material released into the water column by some of the processes is not well understood or known a priori, the modeling approach was to bracket parameters within reasonable ranges to produce a suite of potential results from multiple model runs. Sensitivity analysis to model parameters is used to select the appropriate parameter values for bracketing. Data analysis results include mapping the time series and the maximum values of sedimentation, suspended sediment concentration, and deposition rate. Data were used to quantify various exposure processes that affect coral species in Apra Harbor. The goal of this research is to develop a robust methodology for quantifying and bracketing exposure mechanisms to coral (or other receptors) from dredging operations. These exposure values were utilized in an ecological assessment to predict effects (coral reef impacts) from various dredging scenarios.

  13. Electrical Bioimpedance-Controlled Surgical Instrumentation.

    Science.gov (United States)

    Brendle, Christian; Rein, Benjamin; Niesche, Annegret; Korff, Alexander; Radermacher, Klaus; Misgeld, Berno; Leonhardt, Steffen

    2015-10-01

    A bioimpedance-controlled concept for bone cement milling during revision total hip replacement is presented. Normally, the surgeon manually removes bone cement using a hammer and chisel. However, this procedure is relatively rough and unintended harm may occur to tissue at any time. The proposed bioimpedance-controlled surgical instrumentation improves this process because, for example, most risks associated with bone cement removal are avoided. The electrical bioimpedance measurements enable online process-control by using the milling head as both a cutting tool and measurement electrode at the same time. Furthermore, a novel integrated surgical milling tool is introduced, which allows acquisition of electrical bioimpedance data for online control; these data are used as a process variable. Process identification is based on finite element method simulation and on experimental studies with a rapid control prototyping system. The control loop design includes the identified process model, the characterization of noise as being normally distributed and the filtering, which is necessary for sufficient accuracy ( ±0.5 mm). Also, in a comparative study, noise suppression is investigated in silico with a moving average filter and a Kalman filter. Finally, performance analysis shows that the bioimpedance-controlled surgical instrumentation may also performs effectively at a higher feed rate (e.g., 5 mm/s). PMID:25423656

  14. The use of grafting to improve salt tolerance of tomato in hydroponic conditions

    Directory of Open Access Journals (Sweden)

    P. Jafari

    2012-12-01

    Full Text Available Application of grafting technique could be an approach for increasing salinity resistance of tomato cultivars. To assess the impact of grafting on resistance of tomato to salinity, two varieties of conventional tomato called Hamra and Kevin were grafted on a salt-resistant base, called AR-9704, using chisel grafting method, and were grown in the greenhouse, using a hydroponic system, under three levels of salinity (EC of 2.3, 5.3 and 8.3 dS/m. The results showed that 8.3 dS/m treatment significantly reduced yield per plant. The main reason for this reduction was lower number and weight of the fruits. Interaction of salinity and cultivar was also statistically significant (P<0.01. The use of grafted cultivars of Hamra and Kevin increased yield per plant at different salinity levels. However, this increase was significant at 2.3 dS/m salinity level. At low salinity level (2.3 dS/m, the lycopene content in grafted Hamra and β-carotene content in both grafted Hamra and Kevin cultivars had significant advantage over other treatments. The amount of ascorbic acid and lycopene at moderate and high salinity levels (5.3 and 8.3 dS/m, respectively, and fruit’s soluble solids concentration at salinity level of 8.3 dS/m in grafted cultivars were significantly higher than non-grafted cultivars.

  15. The production of permanent plastic scales-I: photo-impregnation of complicated and precise scale pattern on 'PERSPEX'

    Directory of Open Access Journals (Sweden)

    P.K. Ray Chaudhuri

    1959-10-01

    Full Text Available This paper deals with the production of 'Perspex' protractors where the image pattern becomes integral with the base by a process based on photo-impregnation principle. This process involves building up of an impervious photographic stencil in a resistant material usually termed a 'Resist' (a coating that protects the area it covers from chemical action on the "perspex" surface followed by chemical attack on the exposed portions of the plastic through the unmasked areas of the stencil with a tinted solution of an adequate solvent preparation. The image is rendered visible by the combined softening, penetrating and staining effects initiated by the etching cum dyeing mordant on the base. In course of the treatment the dye gets entrapped and deeply embedded into the material of the base. The tender dyed characters are allowed to harden and set by the evaporation of the solvents. The composition and action of the dye incorporating medium is so governed that it does not chisel by forming image wise cavities due to removal of material from the "perspex" as is usually associated with all commercial photo-mechanical etching processes.

  16. Effects of Reduced Tillage on Crop Yield, Plant Available Nutrients and Soil Organic Matter in a 12-Year Long-Term Trial under Organic Management

    Directory of Open Access Journals (Sweden)

    Wilhelm Claupein

    2013-09-01

    Full Text Available A field experiment was performed in Southwest Germany to examine the effects of long-term reduced tillage (2000–2012. Tillage treatments were deep moldboard plow: DP, 25 cm; double-layer plow; DLP, 15 + 10 cm, shallow moldboard plow: SP, 15 cm and chisel plow: CP, 15 cm, each of them with or without preceding stubble tillage. The mean yields of a typical eight-year crop rotation were 22% lower with CP compared to DP, and 3% lower with SP and DLP. Stubble tillage increased yields by 11% across all treatments. Soil nutrients were high with all tillage strategies and amounted for 34–57 mg kg−1 P and 48–113 mg kg−1 K (0–60 cm soil depth. Humus budgets showed a high carbon input via crops but this was not reflected in the actual Corg content of the soil. Corg decreased as soil depth increased from 13.7 g kg−1 (0–20 cm to 4.3 g kg−1 (40–60 cm across all treatments. After 12 years of experiment, SP and CP resulted in significantly higher Corg content in 0–20 cm soil depth, compared to DP and DLP. Stubble tillage had no significant effect on Corg. Stubble tillage combined with reduced primary tillage can sustain yield levels without compromising beneficial effects from reduced tillage on Corg and available nutrient content.

  17. Effects of 24 Years of Conservation Tillage Systems on Soil Organic Carbon and Soil Productivity

    Directory of Open Access Journals (Sweden)

    Kenneth R. Olson

    2013-01-01

    Full Text Available The 24-year study was conducted in southern Illinois (USA on land similar to that being removed from Conservation Reserve Program (CRP to evaluate the effects of conservation tillage systems on: (1 amount and rates of soil organic carbon (SOC storage and retention, (2 the long-term corn and soybean yields, and (3 maintenance and restoration of soil productivity of previously eroded soils. The no-till (NT plots did store and retain 7.8 Mg C ha−1 more and chisel plow (CP −1.6 Mg C ha−1 less SOC in the soil than moldboard plow (MP during the 24 years. However, no SOC sequestration occurred in the sloping and eroding NT, CP, and MP plots since the SOC level of the plot area was greater at the start of the experiment than at the end. The NT plots actually lost a total of −1.2 Mg C ha−1, the CP lost −9.9 Mg C ha−1, and the MP lost −8.2 Mg C ha−1 during the 24-year study. The long-term productivity of NT compared favorably with that of MP and CP systems.

  18. Concrete decontamination and demolition methods

    International Nuclear Information System (INIS)

    The US Department of Energy (DOE), Division of Environmental Control Technology, requested Nuclear Energy Services to prepare a handbook for the decontamination and decommissioning (D and D) of DOE-owned and commercially-owned radioactive facilities. the objective of the handbook is to provide the nuclear industry with guidance on the state-of-the-art methods and equipment available for decommissioning and to provide the means to estimate decommissioning costs and environmental impact. The methods available for concrete decontamination and demolition are summarized to provide an overview of some of the state-of-the-art techniques to be discussed at this workshop. The pertinent information on each method will include the selection factors such as the rate of performance in terms of concrete removal per unit time (cubic yards per day), manpower required by craft, unit cost (dollars per cubic yard) and the advantages and disadvantages. The methods included in this overview are those that have been routinely used in nuclear and nonnuclear applications or demonstrated in field tests. These methods include controlled blasting, wrecking ball or slab, backhoe mounted ram, flame torch, thermic lance, rock splitter, demolition compound, sawing, core stitch drilling, explosive cutting, paving breaker and power chisel, drill and spall, scarifying, water cannon and grinding

  19. 黑龙江友谊县凤林古城址的发掘%Excavation on the Ancient Fenglin City-site in Youyi County, Heilongjiang

    Institute of Scientific and Technical Information of China (English)

    黑龙江省文物管理委员会

    2004-01-01

    In 2001, the Heilongjiang Provincial Commission for the Preservation of Ancient Monuments carried out survey and excavation on the Fenglin city-site. The unearthed remains can be divided into two phases. The early remains include house-foundations, as well as pottery jars, single-handle jars and balls and jade cicadas. The late vestiges are house-foundations, ash-pits and city-wall ruins. Among the objects from Phase Ⅱ, the pottery consists of jars, bowls, dou stemmed vessels, zeng steamers, cups, spindle whorls, net weights and sculptures. The stone implements embrace axes,knives, grindstones, querns and tubes; the bone artifacts belong to the types of arrowhead, hairpin, belt buckle, chisel-shaped object, oracle bone, etc. The bronzes fall into gilt buttons, ornamental tubes, finger rings, loops and belt buckles; and the ironware, into knives, needles, arrowheads, awls, fishhooks and plates of armor. In addition, there are a number of animal bones, which belong to the wild boar, ox,deer, cat, antelope, roe deer, musk deer, dog and fish. The excavation results reveal the distinctive structural forms of the city and its walls and houses, and suggest that the site represents a new cultural type.

  20. Chewing through the Miocene: an examination of the feeding musculature in the ground sloth Hapalops from South America (Mammalia: Pilosa [v1; ref status: indexed, http://f1000r.es/2pu

    Directory of Open Access Journals (Sweden)

    Virginia L. Naples

    2014-04-01

    Full Text Available Hapalops, a smaller-sized and early sloth of the Megatheroidea, appeared in the middle Miocene Santa Cruz formation of Argentina. This genus is part of the group from which later, larger megatheroids arose, i.e., Nothrotheriops and Megatherium. Many cranial characters support this idea; however Hapalops is not merely a smaller antecedent of the later forms. Specifically, Hapalops retains short anterior caniniform teeth, and a temporomandibular joint elevated above the cheek tooth row; a combination distinct among sloths. An elevated temporomandibular joint occurs in Bradypus, a tree sloth with anterior chisel-shaped teeth instead of caniniforms, and the tree sloth Choloepus, which is aligned with the megalonychids, has anterior caniniforms. Hapalops has an elongated zygomatic ascending process that is reminiscent of that in Bradypus; however, the Bradypus skull is extremely foreshortened while that of Hapalops is elongated, as in nothrotheres, but not deepened as in megatheres. Previous work identified many sloth cranial character complexes, and functional limitations on skull feature combinations. The unique Hapalops character patterns indicate a selective feeder with a mediolaterally oriented grinding stroke during mastication.

  1. DNA memories of early social life.

    Science.gov (United States)

    Hoffmann, A; Spengler, D

    2014-04-01

    The foundations of brain architecture are established early in life through a continuous series of dynamic interactions in which environmental conditions and personal experiences have a significant impact on how genetic predispositions are expressed. New scientific research shows that early social experiences can actually influence how genes are expressed. Thus, the old-school concepts that genes are "chiseled in stone" or that they alone determine development have been disproven. The discovery of the epigenome provides an explanation, at the molecular level, for why and how early positive and negative social experiences give rise to a biological memory that can have lifelong impacts. Signatures associated with the epigenome can be temporary or permanent, affect multiple organ systems, and increase the risk not only for poor physical and mental health outcomes but also for impairments in future learning capacity and behavior. Here, we focus on recent evidence for a role of epigenetic DNA modifications as a potential mechanism that explains how early social life experiences become embedded in the circuitry of the developing brain and are associated with lifelong consequences.

  2. Wear investigations of tools used in bone surgery

    Directory of Open Access Journals (Sweden)

    J. Marciniak

    2007-01-01

    Full Text Available Purpose: The main aim of the work was evaluation of wear rate of surgical drills used in orthopaedic procedureswith the use of plate bone stabilizers.Design/methodology/approach: The authors proposed a wear evaluation methodology of surgical drill edges.The drill wear was evaluated on the basis of measurement of point angle (2 κ and wear land (VBB i VBBmax.The measurements were recorded for preselected number of holes n drilled in a bovine femur. Furthermore,structure investigations and hardness tests of surgical drills were performed.Findings: The investigations revealed diverse wear of the surgical drills. The main mechanism was the wear ofthe chamfered corner and chisel edge of the drills.Research limitations/implications: The improvement of service life of surgical drills can be achieved by thecorrect selection of heat treatment parameters, ensuring the desired geometry of edge and deposition of layerwhich ensure the significant increase of cutting edge hardness.Originality/value: The proposed methodology applied for surgical drills is an effective way of service lifeestimation. The quality of surgical tools influences the safety and the effectiveness of surgical procedures withthe use of plate stabilizers.

  3. Clinical experience of novel interconnected porous hydroxyapatite ceramics for the revision of tumor prosthesis: a case report

    Directory of Open Access Journals (Sweden)

    Osaka Shunzo

    2009-10-01

    Full Text Available Abstract Background As for being cautious with tumor prostheses, revision of uncemented tumor prostheses in particular, it is necessary to remove cortical bone from the stem circumference with a chisel when the stem is extracted. This assures that bone in-growth will occur within the stem in itself. As a result, re-substitution of mass autogenous bone graft round a new stem is subsequently necessary. When rivision of uncemented tumor prosthesis of distal femur was performed, we evade fibula transplant by transplanting interconnected porous hydroxyapatite ceramic (IP-CA: Neobone with a self bone, and reports its experience with the case that acquired enough strength. Case report In this report, we present the case of a 27-year-old female with stem breakage of tumor prosthesis and do revision surgery for prosthetic failure. In the case of revision surgery, autologous bone and Neobone were mixed, and this was transplanted to stem circumference. The Radiological Evaluation System of the ISOLS showed excellent results for all items. She can walk without using a cane or orthosis, and the score of the MSTS is 80%. Conclusion When revision of uncemented tumor prostheses of the distal femur was performed, we avoided fibula graft by using Neobone with the patient's own bone tissue. Our experience with this case may indicate that adequate strength is achieved.

  4. Morphology and topographic anatomy of the spinal cord of the red-footed tortoise (Geochelone carbonaria Spix, 1824

    Directory of Open Access Journals (Sweden)

    Rafael C Carvalho

    2011-12-01

    Full Text Available The aim of this study was to describe the topography of the spinal cord of the red-footed tortoise to establish a morphological basis for applied research in anesthesiology and morphology. Six tortoises from the state of Maranhão (Brazil that had died of natural causes were used. The common carotid artery was used to perfuse the arterial system with saline solution (heated to 37ºC and to fix the material with a 20% formaldehyde solution. The specimens were then placed in a modified decalcifying solution for 72 hours to allow dorsal opening of the carapace with a chisel and an orthopedic hammer. Dissection of the dorsal musculature and sectioning of the vertebral arches were performed to access the spinal cord. The results revealed the spinal cord of G. carbonaria to be an elongated, whitish mass that reached the articulation between the penultimate and last caudal vertebrae. The cervical intumescence (Intumescentia cervicalis was located between vertebral segments C5 and T1, whereas the lumbosacral intumescence (Intumescentia lumbalis was located between T6 and Ca1.

  5. Designing an intelligent system to predict drill wear by using of motor current and fuzzy logic method - doi: 10.4025/actascitechnol.v35i4.15647

    Directory of Open Access Journals (Sweden)

    Aydin Salimi

    2013-10-01

    Full Text Available In automation flexible manufacturing systems, tool wear detection during the cutting process is one of the most important considerations. This study presents an intelligent system for online tool condition monitoring in drilling process. In this paper, analytical and empirical models have been used to predict the thrust and cutting forces on the lip and chisel edges of a new drill. Also an empirical model is used to estimate tool wear rate and force values on the edges of the worn drill .By using the block diagram of machine tool drives, the changes in the feed and spindle motor currents are simulated, as wear rate increases. To predict tool wear rate, fuzzy logic capabilities have been used to develop an intelligent system. The simulation results presented with MATLAB software show the effectiveness of proposed system for on-line drill wear monitoring. This is confirmed by comparing the measured and estimated values with each other in which the value of R2 was obtained 0.9367 in the regression graph.  

  6. Soil tillage, water erosion, and calcium, magnesium and organic carbon losses

    Directory of Open Access Journals (Sweden)

    Bertol Ildegardis

    2005-01-01

    Full Text Available Soil tillage influences water erosion, and consequently, losses of calcium, magnesium and organic carbon in surface runoff. Nutrients and organic carbon are transported by surface runoff in particulate form, adsorbed to soil colloids or soluble in water, depending on the soil tillage system. This study was carried out on an Inceptisol, representative of the Santa Catarina highlands, southern Brazil, between November 1999 and October 2001, under natural rainfall. The soil tillage treatments (no replications were: no-tillage (NT, minimum soil tillage with chiseling + disking (MT, and conventional soil tillage with plowing + two diskings (CT. The crop cycles sequence was soybean (Glycine max, oats (Avena sativa, beans (Phaseolus vulgaris and vetch (Vicia sativa. Conventional soil tillage treatment with plowing + two disking in the absence of crops (BS was also studied. Calcium and magnesium concentrations were determined in both water and sediments of the surface runoff, while organic carbon was measured only in sediments. Calcium and magnesium concentrations were greater in sediments than in surface runoff, while total losses of these elements were greater in surface runoff than in sediments. The greatest calcium and magnesium concentrations in surface runoff were obtained under CT, while in sediments the greatest concentration occurred under MT. Organic carbon concentration in sediments did not differ under the different soil tillage systems, and the greatest total loss was under CT system.

  7. Methods of septum surgery (septoplasty with cresto- and suturotomy

    Directory of Open Access Journals (Sweden)

    Gulimbay Babakhanov

    2012-12-01

    Full Text Available High frequency of a combination of such symptoms as a curvature of a nose septum (NSC dento-maxillary anomalies (DMA, high standing of the palatum, reduction of the horizontal and vertical sizes of a cavity of a nose are united and named as Khasanov rhinomaxillary (orthodontic rhinological symptom complex. The operative intervention - septum surgery with crestosuturotomy is prescribed to patients with Khasanov symptom complex. The musculomucosal graft is detached, a cartilage is separated from the bottom of a nasal cavity and moved in the opposite side. Thus the nasal crest of a palatal shoot of the top jaw becomes visible and it is removed with a grooved chisel (crestotomy. Suturotomy is made to sutura palatina mediana of the bony palate which is from 2- to 5-mm deep and up to 3-4-mm wide in the form of a trihedral trench. Our experience shows that, patients with Khasanov symptom complex after surgical correction of the nasal septum and osteotomy of the nasal crest of a palatal shoot of the top jaw, the orthodontic disclosing of a palatal stitch occurs several times faster, anomaly relapses of dento-maxillary systems decrease.

  8. A case of mushroom shape temporal bone osteoma.

    Science.gov (United States)

    Akamatsu, Tadashi; Tanaka, Rica; Fukui, Tsuyoshi; Miyasaka, Muneo; Yamada, Shinya

    2009-09-20

    A cranial vault Osteoma is relatively common benign tumor. Mushroom shaped skull osteoma is, however, extremely rare. Twenty seven years old female developed slow growing hard mass posterior to the ear. CT scan revealed a mushroom shaped osseous mass approximately 2.5 cm in diameter protruding from the temporal bone at the site of asterion. And the tumor was located over the right sigmoid sinus. The sigmoid sinus engraved approximately 4mm to the tumor and had a branching to one emissaries' vein. Operation was performed under general anesthesia. The tumor was excised first by cutting the base of the tumor, and then residual tumor was grinded using a round head cutting bar. A chisel dissection was not recommended because of underlining sinus. Histological findings were consistent with a benign osteoma. The postoperative course was uneventful. CT examination immediately done after operation revealed no evidence of intracranial hemorrhage, or injury of vessels. Osetoma was excised, and the surface of cranial bone at the operation site was smooth and cosmetically acceptable. At 6-months follow up, patient remains asymptomatic and recurrence free. CT examination with Multi Planer Reconstruction imaging or 3D reconstruction is highly recommended for the operational planning of cranial osteoma.

  9. Radioecological estimation of biotops in the territory of Imishli region of Azerbaijan Republic

    International Nuclear Information System (INIS)

    Full text : The ecosystem level of structurisation of a live matter is the basic subject of ecological, in particular radio ecological science. Quality of biotopes - a complex of the lifeless nature on which all inhabitants of the given ecosystem live, is a basic condition of its existence. In the given work it was investigated the maintenance of natural and artificial radionuclides in an arable layer of soils, on the basis of the received data estimated quality of the biotopes located in territory of Imishli administrative area of Azerbaijan. Imishli is one of the areas of Republic most subject to strong anthropogenous loading. Along with agricultural, in area territory works on oil recovery are conducted that also can lead to pollution of soils with natural radionuclides, containing as a part of chisel waters (2235U, 2238U, 2232Th, 2226Ra, 2228Ra) and with oil. On the basis of the spent radiospectrometer analyses of the soil samples which have been selected from enough of the soil cuts, the radioecological situation on all area has been estimated and corresponding cards were made

  10. Skeuomorphism, Boundary Objects and Socialization of the Chalcolithic Metallurgy in the Southern Levant

    Directory of Open Access Journals (Sweden)

    Milena Gošić

    2016-02-01

    Full Text Available Metalworking emerged in the southern Levant as a new ritual practice during the late phase of the Ghassulian culture, ca. 4300–3900 BC. Ghassulian metalworkers cast objects in both pure and alloyed copper. All the artifacts produced during this time span were ritual. The aim of the present paper is to discuss the socialization process of the Ghassulian metallurgy and its copper objects, by using the concepts of skeuomorphism and boundary objects. Ghassulian copper artifacts can be divided into two groups. The first group consists of artifacts, such as maceheads, chisels and axes, which were produced in stone before the Ghassulian metallurgy appeared. The second group consists of artifacts produced only in metal, including scepters, standards, “crowns” and horns, which were decorated by motifs found on various other early and late Ghassulian ritual artifacts. The artifacts of the first group are skeuomorphic objects, the morphology of which was widely recognized in early and late Ghassulian contexts. These were boundary objects, belonging both to the realm of the new social world of metallurgy and the preexisting world of Ghassulian ritual behavior. Their purpose was to introduce metallurgy to people, both in the Beer Sheva settlements and in other parts of the southern Levant, who did not practice it, as a technology firmly rooted in the Ghassulian tradition. The second group consists of more innovative objects that demonstrated the transformational potential of metallurgy and the superior control metalworkers had over the material world

  11. Uso de lodo de esgoto na produção de tapetes de grama esmeralda Use of sewage sludge in zoysiagrass production

    Directory of Open Access Journals (Sweden)

    Clarice Backes

    2009-07-01

    systems (with and without chisel use, to break a compacted surface layer. The sludge used came from "Estação de Tratamento de Esgoto de Jundiaí/SP". The doses of sludge applied correspond to the doses of 100, 200, 300 and 400kg ha-1 of nitrogen. 165 days after sewage sludge application, the dose of 31Mg ha-1 allowed the complete closing (100% of soil cover rate and greater resistance of the zoysiagrass sod. The same results were found when chemical fertilization was used. The control and the plots that received 10Mg ha-1 of sludge did not formed sod. The sewage sludge applied to surface promoted reduction of zoysiagrass sod mass. The use of surface chisel reduced the strength of zoysiagrass sod. The heavy metals values found in sewage sludge were below the limit set by the rules governing the sewage sludge use in agriculture.

  12. Describing soil surface microrelief by crossover length and fractal dimension

    Directory of Open Access Journals (Sweden)

    E. Vidal Vázquez

    2007-05-01

    Full Text Available Accurate description of soil surface topography is essential because different tillage tools produce different soil surface roughness conditions, which in turn affects many processes across the soil surface boundary. Advantages of fractal analysis in soil microrelief assessment have been recognised but the use of fractal indices in practice remains challenging. There is also little information on how soil surface roughness decays under natural rainfall conditions. The objectives of this work were to investigate the decay of initial surface roughness induced by natural rainfall under different soil tillage systems and to compare the performances of a classical statistical index and fractal microrelief indices. Field experiments were performed on an Oxisol at Campinas, São Paulo State (Brazil. Six tillage treatments, namely, disc harrow, disc plow, chisel plow, disc harrow + disc level, disc plow + disc level and chisel plow + disc level were tested. Measurements were made four times, firstly just after tillage and subsequently with increasing amounts of natural rainfall. Duplicated measurements were taken per treatment and date, yielding a total of 48 experimental surfaces. The sampling scheme was a square grid with 25×25 mm point spacing and the plot size was 1350×1350 mm, so that each data set consisted of 3025 individual elevation points. Statistical and fractal indices were calculated both for oriented and random roughness conditions, i.e. after height reading have been corrected for slope and for slope and tillage tool marks. The main drawback of the standard statistical index random roughness, RR, lies in its no spatial nature. The fractal approach requires two indices, fractal dimension, D, which describes how roughness changes with scale, and crossover length, l, specifying the variance of surface microrelief at a reference scale. Fractal parameters D and l, were estimated by two independent self-affine models

  13. Comparison of surface emissions and subsurface distribution of cis- and trans-1,3-dichloropropene and chloropicrin in sandy field beds covered with four different plastic films.

    Science.gov (United States)

    Ou, Li-Tse; Thomas, John E; Allen, L Hartwell; Vu, Joseph C; Dickson, Donald W

    2008-06-01

    The purpose of this study was to conduct a field study at a Florida field site on surface emissions and subsurface distribution of cis-and trans-1,3-dichloropropene (1,3-D) and chloropicrin (CP) in raised beds injected with Telone C35 with four replications. A total of 16 beds were applied with Telone C35 by chisel injection and covered with four different plastic films, 4 beds for each film. Each bed was installed with five 20-cm long soil pore air probes and a surface air collection pan at arbitrarily locations along the length of each bed for sampling soil pore air and surface air, respectively, for analysis of the three biologically active compounds, cis- and trans-1,3-D and CP. We found that average concentrations of the three compounds at 20-cm depth among the beds covered with four different plastic films generally were not statistically different. Among the four beds covered with the same plastic film, average concentrations of the three compounds were statistically different only in the four metallic PE covered beds at 5 and 24 hours after injection. Volatilization rates of the three compounds among the beds covered with four different plastic films, with the exception of CP at 48 hours after injection, were not statistically different. It appeared that initial upward diffusion and volatilization flux were influenced by solar radiation. Initial subsurface concentrations of the three compounds and volatilization flux, especially cis-1,3-D, were greater in the beds on the east side of the field than that in the beds on the west side of the field. Whether or not difference in initial subsurface concentrations of the compounds between east side beds and west side beds may influence fumigant efficacy remains to be determined.

  14. Determination of paleoseismic activity over a large time-scale: Fault scarp dating with 36Cl

    Science.gov (United States)

    Mozafari Amiri, Nasim; Tikhomirov, Dmitry; Sümer, Ökmen; Özkaymak, Çaǧlar; Uzel, Bora; Ivy-Ochs, Susan; Vockenhuber, Christof; Sözbilir, Hasan; Akçar, Naki

    2016-04-01

    Bedrock fault scarps are the most direct evidence of past earthquakes to reconstruct seismic activity in a large time-scale using cosmogenic 36Cl dating if built in carbonates. For this method, a surface along the fault scarp with a minimum amount of erosion is required to be chosen as an ideal target point. The section of the fault selected for sampling should cover at least two meters of the fault surface from the lower part of the scarp, where intersects with colluvium wedge. Ideally, sampling should be performed on a continuous strip along the direction of the fault slip direction. First, samples of 10 cm high and 15 cm wide are marked on the fault surface. Then, they are collected using cutters, hammer and chisel in a thickness of 3 cm. The main geometrical factors of scarp dip, scarp height, top surface dip and colluvium dip are also measured. Topographic shielding in the sampling spot is important to be estimated as well. Moreover, density of the fault scarp and colluvium are calculated. The physical and chemical preparations are carried in laboratory for AMS and chemical analysis of the samples. A Matlab® code is used for modelling of seismically active periods based on increasing production rate of 36Cl following each rupture, when a buried section of a fault is exposed. Therefore, by measuring the amount of cosmogenic 36Cl versus height, the timing of major ruptures and their offsets are determined. In our study, Manastır, Mugırtepe and Rahmiye faults in Gediz graben, Priene-Sazlı, Kalafat and Yavansu faults in Büyük Menderes graben and Ören fault in Gökava half-graben have been examined in the seismically active region of Western Turkey. Our results reconstruct at least five periods of high seismic activity during the Holocene time, three of which reveal seismic ruptures beyond the historical pre-existing data.

  15. Influence of prior thermal ageing on tensile deformation and fracture behaviour of forged thick section 9Cr-1Mo ferritic steel

    International Nuclear Information System (INIS)

    Tensile tests were performed on specimens in quenched and tempered (Q + T) and thermally aged (TA) conditions over a wide temperature range (300-873 K) to assess the influence of prior thermal ageing on tensile deformation and fracture behaviour of forged thick section 9Cr-1Mo ferritic steel. Prior thermal ageing at 793 and 873 K for durations ranging from 10 to 5000 h did not cause a significant change in room temperature tensile properties. However, a marginal decrease in yield strength and reduction in area were observed for specimens aged for longer durations at 793 and 873 K. Prior thermal ageing at 793 K for 5000 h and at 873 K for 1000 and 5000 h produced significant reduction in strength values at intermediate temperatures (523-723 K) compared to that observed at high temperatures. At intermediate temperatures, the alloy in all heat treatment conditions exhibited serrated flow, a manifestation of dynamic strain ageing (DSA). The significant loss of strength in thermally aged conditions at intermediate temperatures has been attributed to reduced propensity to DSA. The elongation to fracture values at temperatures in the range 300-873 K were affected little by prior thermal ageing, whereas the reduction in area exhibited a decrease in the value with increasing thermal ageing. The fracture mode remained transgranular ductile at all test conditions investigated in the present study. However, specimens aged for longer durations exhibited chisel fracture at room and intermediate temperatures due to split in the martensite lath boundaries. The influence of thermal ageing on room temperature tensile properties of the forging remained similar to that reported for thin section 9Cr-1Mo steel. (orig.)

  16. Effects of tillage methods, corn residue mulch and n fertilizer levels on the wheat crop productivity under the rain fed condition of loess plateau china

    International Nuclear Information System (INIS)

    A 2 years study was conducted to assess the effects of different tillage methods (Chisel plough tillage, Zero-tillage, Rotary tillage and Mould board plough tillage), two mulch levels (M0 i.e. No corn residue mulch and M1 i.e. Corn residue mulch) and 5 N fertilizer levels (0, 80, 160, 240 and 320 kg N/ha) on the wheat crop productivity under the rain fed condition of Loess Plateau, China. Factorial experiment with three replications, having strip, split-split arrangement, with tillage methods in the main plots, mulch levels in sub- plots and N-fertilizer levels in the sub-sub plots was used for this study. Due to variations in rainfalls, during the year, 2010-11, maximum grain yields i.e. 6.58 t/ha and 6.72 t/ha were recorded in case of Zero tillage planting method and similarly in case of 80 kg N/ha, while during the cropping year 2011-12 equal grain yields were recorded in case of all tillage methods, however maximum grain yield (7.46 t /ha) was recorded in case of 320 kg N/ha, N fertilizer level. On two years average basis, maximum grain yields i.e. 6.75 t/ha and 6.80 t/ha were recorded in case of Zero tillage planting method and similarly in case of 80 kg N/ha as compared with the other tillage methods or N fertilizer levels. Use of mulch reduced > 40% weeds infestation. Economic analysis shows that Zero tillage and minimum use of N fertilizer according to the projected rainfalls along with the use of mulch are both economic and environmental friendly. (author)

  17. Effect of cropland management and slope position on soil organic carbon pool at the North Appalachian Experimental Watersheds

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Yueli; Lal, Rattan; Owens, Lloyd; Izaurralde, R Cesar C.; Post, W M.; Hothem, Daniel

    2002-12-01

    Soil organic matter is strongly related to soil type, landscape morphology, and soil and crop management practices. Therefore, long-term (15-36-years) effects of six cropland management systems on soil organic carbon (SOC) pool in 0-30 cm depth were studied for the period of 1939-1999 at the North Appalachian Experimental Watersheds (<3 ha, Dystric Cambisol, Haplic Luvisol, and Haplic Alisol) near Coshocton, OH, USA. Six management treatments were: (1) no tillage continuous corn with NPK (NC); (2) no tillage continuous corn with NPK and manure (NTC-M); (3) no tillage corn?soybean rotation (NTR); (4) chisel tillage corn?soybean rotation (CTR); (5) moldboard tillage with corn?wheat?meadow?meadow rotation with improved practices (MTR-I); (6) moldboard tillage with corn?wheat?meadow?meadow rotation with prevalent practices (MTR-P). The SOC pool ranged from 24.5Mgha?1 in the 32-years moldboard tillage corn (Zea mays L.)?wheat (Triticum aestivum L.)?meadow?meadow rotation with straight row farming and annual application of fertilizer (N:P:K = 5:9:17) of 56?112 kg ha?1 and cattle (Bos taurus) manure of 9Mg ha?1 as the prevalent system (MTR-P) to 65.5Mgha?1 in the 36-years no tillage continuous corn with contour row farming and annual application of 170?225 kgNha?1 and appropriate amounts of P and K, and 6?11Mgha?1 of cattle manure as the improved system (NTC-M).

  18. The WELSONS experiment: overview and presentation of first results on the surface atmospheric boundary-layer in semiarid Spain

    Directory of Open Access Journals (Sweden)

    J.-P. Frangi

    Full Text Available This study presents the preliminary results of the local energy budget and dynamic characteristics of the surface atmospheric boundary-layer (SBL during the WELSONS (wind erosion and losses of soil nutrients in semiarid Spain experiment. Some Mediterranean regions suffer land degradation by wind erosion as a consequence of their particular soil and climate conditions and inappropriate agricultural practice. In Spain, where land degradation by water erosion is well known, the lack of field studies to quantify soils losses by wind erosion resulted in the European Community organizing a scientific program for this specific issue. The European programme known as WELSONS was devoted to study the wind erosion process in central Aragon (NE Spain. This multidisciplinary experiment, which began in 1996 and finished in 1998, was carried out over an agricultural soil which was left fallow. Within the experimental field, two plots were delimited where two tillage treatments were applied, a mould-board ploughing (or conventional tillage denoted CT and chisel ploughing (reduced tillage denoted RT. This was to study on bare soil the influence of tillage method on surface conditions, saltation flux, vertical dust flux, erosion rates, dynamics characteristics such as friction velocity, roughness length, etc., and energy budget. The partitioning of the available energy, resulting from the dynamics of the SBL, are quite different over the two plots because of their own peculiar soil and surface properties. The first results show that the RT treatment seems to provide a wind erosion protection. Because of the long data recording time and particular phenomena (formation of a crust at the soil surface, very dry conditions, high wind speed for instance, these microclimatological data acquired during the WELSONS programmes may be helpful to test atmospheric boundary-layer models coupled with soil models.

    Key words: Hydrology (desertification - Meterology and

  19. Shear bond strength of orthodontic brackets after acid-etched and erbium-doped yttrium aluminum garnet laser-etched

    Directory of Open Access Journals (Sweden)

    Shiva Alavi

    2014-01-01

    Full Text Available Background: Laser ablation has been suggested as an alternative method to acid etching; however, previous studies have obtained contrasting results. The purpose of this study was to compare the shear bond strength (SBS and fracture mode of orthodontic brackets that are bonded to enamel etched with acid and erbium-doped yttrium aluminum garnet (Er:YAG laser. Materials and Methods: In this experimental in vitro study, buccal surfaces of 15 non-carious human premolars were divided into mesial and distal regions. Randomly, one of the regions was etched with 37% phosphoric acid for 15 s and another region irradiated with Er:YAG laser at 100 mJ energy and 20 Hz frequency for 20 s. Stainless steel brackets were then bonded using Transbond XT, following which all the samples were stored in distilled water for 24 h and then subjected to 500 thermal cycles. SBS was tested by a chisel edge, mounted on the crosshead of universal testing machine. After debonding, the teeth were examined under Χ10 magnification and adhesive remnant index (ARI score determined. SBS and ARI scores of the two groups were then compared using t-test and Mann-Whitney U test. Significant level was set at P < 0.05. Results: The mean SBS of the laser group (16.61 ± 7.7 MPa was not significantly different from that of the acid-etched group (18.86 ± 6.09 MPa (P = 0.41. There was no significant difference in the ARI scores between two groups (P = 0.08. However, in the laser group, more adhesive remained on the brackets, which is not suitable for orthodontic purposes. Conclusion: Laser etching at 100 mJ energy produced bond strength similar to acid etching. Therefore, Er:YAG laser may be an alternative method for conventional acid-etching.

  20. Restauração da estrutura do solo por sequências culturais implantadas em semeadura direta, e sua relação com a erosão hídrica em distintas condições físicas de superfície Restoration of the soil structure by crop sequences established in no-till, as related to water erosion in distinct surface physical conditions

    Directory of Open Access Journals (Sweden)

    Jeane Cruz Portela

    2010-08-01

    ísicas internas ou subsuperficiais. De modo geral, todas as sequências culturais foram eficazes na restauração da estrutura do solo no período da experimentação: aquela que envolveu teosinto no que se refere à perda de solo e água e a que envolveu milho + feijão-miúdo e milheto no tocante à perda de solo foram as que melhor controlaram o processo de erosão hídrica pluvial. A superfície de solo não mobilizada e com pouca cobertura por resíduo cultural foi a que mais favoreceu a enxurrada e a erosão, independentemente da presença e do tipo de crosta, especialmente quando esta última foi levemente rompida antes da aplicação da chuva. A superfície de solo inteiramente coberta por resíduo cultural - tenha sido ela não mobilizada ou recém-escarificada - controlou a enxurrada de modo eficaz e impediu totalmente a erosão. A superfície de solo recém-gradeada sobre a superfície escarificada há um mês, embora com o solo mais mobilizado de todos e descoberto, praticamente não apresentou perdas de solo e água, contrariando o que se esperava.Soil structure plays a prominent role in plant growth and erosion control, and consequently in food production and soil and water conservation. This research was developed with the objective of implementing and accompanying the restoration process of the structure of a degraded soil, by planting crop sequences under no-tillage (autumn-winter and spring-summer, grass and legume, in single and intercropped systems, and later verifying the relations with water and soil losses caused by rainfall erosion, under distinct surface physical conditions (untilled soil, with and without crust; freshly-tilled soil by chiseling and by chiseling followed by disking after one month, and crop residue covering 100, 18, and 0 %. The field study was developed under simulated rainfall, at the Agriculture Experimental Station of the Federal University of Rio Grande do Sul (EEA/UFRGS, in Rio Grande do Sul State, Brazil, from May 2004 to Decembe

  1. Performance evaluation of bolt-cutter system on first Taurus launch

    Science.gov (United States)

    Baban, F.; Williams, R.; Amimoto, S.; Hansen, W.; Bixler, T.

    1994-10-01

    In rapid response to the request of the Space Test and Experimentation Directorate in Space Launch Operations, a launch-critical experimental investigation was conducted to evaluate the performance of a particular bolt-cutter system for separating stages on the first Taurus launch. The tests were to examine the variation of tension preloading on the bolt system and to demonstrate the tolerable margin on this parameter for such launches with the new types of bolts since the preloading was known to vary as much as 12% from a preset value before launch. We planned and carried out the experiment, designed and assembled the fixture to properly simulate flight application, and developed diagnostics. Four bolt cutters were purchased from the manufacturer for these tests, and one was provided by the contractor. In addition to the obvious requirement to demonstrate the successful severing of bolts under varying preloads, ignition-wire current and timing of chisel impact on the bolt were monitored. An optical diagnostic was designed to determine the flyout velocity and kinetic energy of the broken pieces. These latter measurements will be useful in anchoring performance codes simulating and assessing the structural dynamics of the bolt-cutter function for future missions. The tests were conducted successfully and the bolts were severed successfully in all five tests. The preloads were successively lowered from 2,500 lb to 2,250, 2,000, 1,500, and 1,000 lb These tests contributed in a timely manner to the STEP launch decision and to launch mission assurance. They demonstrated important margin to the nominally set 3,200 lb. preload. The entire complicated experimental program from inception to completion was accomplished in less than three weeks.

  2. Comparison of Surface Water Quality and Yields from Organically and Conventionally Produced Sweet Corn Plots with Conservation and Conventional Tillage.

    Science.gov (United States)

    Edgell, Joshua; Osmond, D L; Line, D E; Hoyt, G D; Grossman, J M; Larsen, E M

    2015-11-01

    Organic agricultural systems are often assumed to be more sustainable than conventional farming, yet there has been little work comparing surface water quality from organic and conventional production, especially under the same cropping sequence. Our objective was to compare nutrient and sediment losses, as well as sweet corn ( L. var. ) yield, from organic and conventional production with conventional and conservation tillage. The experiment was located in the Appalachian Mountains of North Carolina. Four treatments, replicated four times, had been in place for over 18 yr and consisted of conventional tillage (chisel plow and disk) with conventional production (CT/Conven), conservation no-till with conventional production (NT/Conven), conventional tillage with organic production (CT/Org), and conservation no-till with organic production (NT/Org). Water quality (surface flow volume; nitrogen, phosphorus, and sediment concentrations) and sweet corn yield data were collected in 2011 and 2012. Sediment and sediment-attached nutrient losses were influenced by tillage and cropping system in 2011, due to higher rainfall, and tillage in 2012. Soluble nutrients were affected by the nutrient source and rate, which are a function of the cropping system. Sweet corn marketable yields were greater in conventional systems due to high weed competition and reduced total nitrogen availability in organic treatments. When comparing treatment efficiency (yield kg ha /nutrient loss kg ha ), the NT/Conven treatment had the greatest sweet corn yield per unit of nutrient and sediment loss. Other treatment ratios were similar to each other; thus, it appears the most sustainably productive treatment was NT/Conven. PMID:26641338

  3. The current status and future prospects of computer-assisted hip surgery.

    Science.gov (United States)

    Inaba, Yutaka; Kobayashi, Naomi; Ike, Hiroyuki; Kubota, So; Saito, Tomoyuki

    2016-03-01

    The advances in computer assistance technology have allowed detailed three-dimensional preoperative planning and simulation of preoperative plans. The use of a navigation system as an intraoperative assistance tool allows more accurate execution of the preoperative plan, compared to manual operation without assistance of the navigation system. In total hip arthroplasty using CT-based navigation, three-dimensional preoperative planning with computer software allows the surgeon to determine the optimal angle of implant placement at which implant impingement is unlikely to occur in the range of hip joint motion necessary for daily activities of living, and to determine the amount of three-dimensional correction for leg length and offset. With the use of computer navigation for intraoperative assistance, the preoperative plan can be precisely executed. In hip osteotomy using CT-based navigation, the navigation allows three-dimensional preoperative planning, intraoperative confirmation of osteotomy sites, safe performance of osteotomy even under poor visual conditions, and a reduction in exposure doses from intraoperative fluoroscopy. Positions of the tips of chisels can be displayed on the computer monitor during surgery in real time, and staff other than the operator can also be aware of the progress of surgery. Thus, computer navigation also has an educational value. On the other hand, its limitations include the need for placement of trackers, increased radiation exposure from preoperative CT scans, and prolonged operative time. Moreover, because the position of a bone fragment cannot be traced after osteotomy, methods to find its precise position after its movement need to be developed. Despite the need to develop methods for the postoperative evaluation of accuracy for osteotomy, further application and development of these systems are expected in the future. PMID:26850921

  4. Greenhouse gas fluxes induced by tillage and fertilisation in an organic grass-clover-wheat sequence

    Science.gov (United States)

    Krauss, Maike; Ruser, Reiner; Hansen, Sissel; Mäder, Paul; Gattinger, Andreas

    2015-04-01

    Reduced tillage is technically a challenging task in organic arable farming due to the weed competition but also concerning the destruction of grass-clover leys. Regarding its climate impact, there are hardly any data existing. Soil-derived greenhouse gas fluxes were therefore monitored in a long-term field trial in Frick/CH. The trial is arranged in a strip-split-plot design on a heavy clay soil and compares since 2002 conventional tillage (up to 15 cm deep mouldboard ploughing) with reduced tillage (skim plough 5 cm deep and occasional chisel ploughing). In addition, cattle slurry only (SL) is compared with a slurry/manure compost treatment (MC) at a rate of 90 kg N/year. MC plots received one manure compost and two slurry batches, the latter applied with SL the same day but with half the amount. The overall management is in compliance with the EU organic farming regulation. Nitrous oxide and methane fluxes were monitored in a two-year period including a grass-clover ley, its destruction and a subsequent winter wheat crop. We adjusted the closed chamber sampling method developed by Flessa et al. (1995) with eight replicates for each treatment. Gas and soil sampling took place weekly with additional measurements after fertiliser and tillage management. Soil samples were analysed for mineralised nitrogen, dissolved organic carbon and water filled pore space. Flux calculation included linear and non-linear regression calculated with the HMR-Model after Pedersen et al. (2010) and Fuss et al. (unpublished). N2O fluxes calculated with the non-linear model were 10% higher than calculated with the linear model only. First results for the grass-clover period show no significant differences in N2O fluxes neither between reduced tillage and ploughing nor between slurry and manure compost/slurry application. However, ley destruction induced high N2O emissions which will be discussed with the subsequent wheat period.

  5. Un Yacimiento del Bronce en el Término de Villasbuenas (Salamanca

    Directory of Open Access Journals (Sweden)

    Juan de MANUEL ALFAGEME

    2009-10-01

    Full Text Available RESUMEN: Este pequeño trabajo se refiere a un yacimiento de superficie ele la Edad del Bronce que se encuentra en el término municipal de Villasbuenas, al noroeste de la provincia de Salamanca, en el que ha aparecido un conjunto de hachas y otros objetos en piedra pulimentada (mazos, escoplo, etc., cantos de cuarcita utilizados como percutores y otros tallados, algunos de los cuales tienen una característica importante: tienen perfectamente pulida la zona de separación entre la corteza y la parte tallada, y fragmentos de cerámica, algunos de ellos decorados, preferentemente con puntos. Por la comparación del yacimiento con otros más o menos cercanos hemos podido dar una cronología aproximativa, sobre todo en función de la cerámica, situándolo en el Bronce Inicial, con todas las reservas que se puedan poner, al ser de superficie y además no muy abundante.ABSTRACT: This short work deals with a surfai - site of the Bronze Age, to be found in the municipal boundaries of Villasbuenas, in the North-west of the province of Salamanca. There, wera discovered a set of axes and other objects made of polished stone (mallets, chisels, etc.. pieces of quartz and other stones used as cutting or carving tools, some of which with an important chciructeristic: the zone of separation between the rough stone and the carved part of the stone is perfectty polished, and there are fragments of ceramicssome of which are decorated usually with dots. Comparing this site with neigh bouring ones we have been able to give an approximate chronology especially by examining the ceramics: we date it as belonging to the Bronze Age with all reservations due to the fact that it is a surfacing site containing few objects.

  6. Effect of restoration size on fracture resistance of bonded amalgam restorations.

    Science.gov (United States)

    Lindemuth, J S; Hagge, M S; Broome, J S

    2000-01-01

    The purpose of this study was to determine the effect of restoration size on the fracture strength of amalgam restorations bonded with Amalgambond Plus (with HPA). Research has shown that this adhesive is dispersed throughout the unset amalgam during condensation and that a decrease in diametral tensile strength, proportional to the amount of adhesive incorporated into the unset amalgam, has resulted. Smaller cavity preparations have a higher ratio of surface area to volume than do larger preparations, and it was anticipated that a proportionately greater amount of adhesive would be incorporated into smaller amalgam restorations. Sixty extracted human molars were divided into four groups of 15 teeth and mounted in tray acrylic-filled PVC cylinders. Shallow approximo-occlusal channels were prepared in two groups. One group was restored with Amalgambond Plus and Tytin amalgam, the other with just Tytin amalgam. Larger proximo-occlusal preparations were made in the remaining two groups, then restored in the same fashion. Samples were stored in 37 degrees C for at least 24 hours, then thermocycled from 5-55 degrees C 1000 times with a one-minute dwell time. Specimens were mounted in a Universal Testing Machine, and a chisel was applied to the restorations in compression mode at a crosshead speed of 5.0 mm/minute until bulk fracture of the amalgam occurred. The results indicated no difference in bulk fracture strengths between large amalgam restorations restored with and without Amalgambond Plus. However, small amalgam restorations restored with Amalgambond Plus exhibited significantly greater (p < 0.025) bulk fracture strengths than small amalgam restorations restored without use of the adhesive. PMID:11203813

  7. Hylotrupes bajulus (L. (Col., Cerambycidae: nutrition and attacked material

    Directory of Open Access Journals (Sweden)

    Chiappini, E

    2010-09-01

    Full Text Available Hylotrupes bajulus, attacks softwood utilising the cellulose contained in wood walls as food. The fibre is digested in variable percentages, depending on the type of analysis, 20 to 48% and, according to some authors, without the assistance of intestinal symbiotic microorganisms. Furthermore, there is published work referring to Hylotrupes, concluding that "starch” … “plays no role in the nutrition of the larvae". Nevertheless, considering that attacks of this species decrease with wood seasoning increasing and having been demonstrated, and that “lignin degradation products of spruce wood do not influence larvae development”, it is possible to suppose that cell walls alone are not sufficient to feed this wood boring species. Furthermore, Hylotrupes larvae have chisel shaped mandibles, similar to those of powder post beetle larvae that feed on starch and need to pulverise the wood to access the cellular content. Preliminary research suggests an utilization of wood fibre as well as of starch by larvae of H. bajulus. Therefore, the purpose of this research is to test the degree of digestion of wood fibre from different sources (sapwood or heartwood and the possible role of symbiotic microorganisms. Larvae of H. bajulus were grown on synthetic diets made of purified wood fibre and/or starch as main components supplied with mineral and vitamin. Substrates and frass were analysed for fibre fractions, starch and acid insoluble ash, the latter used as an indigestible marker. Larvae purified DNA was analysed by means of metagenomics approaches carried out by direct retrieval and analysis of 16S rRNA gene sequences free of cultural bias in order to discover the bacterial diversity from larva alimentary channel alone. Larvae of H. bajulus seem be able to digest either fibre or starch, and a role for symbiotic bacteria is supposed.

  8. Telling stories out of school: experiencing the paramedic's oral traditions and role dissonance.

    Science.gov (United States)

    Lazarsfeld-Jensen, Ann

    2014-11-01

    Role dissonance is an uncomfortable experience for graduate paramedics, and some blame their university education for the problem. For paramedics the conflict is between identifying as a rescuer and acting largely as a care giver. With vocational pathways into so many uniformed professions closing down in preference for graduate entrants, young new professionals have to negotiate a rapidly changing work culture. Their older colleagues may be challenged and threatened by the new order. For paramedics the problem is compounded by the newness of its place in the tertiary landscape. Since 9/11 young people have been increasingly attracted to rescue roles. Yet in Australia there is increasing need and scope for health workers in remote and aging populations, a preference not immediately attractive to young people hoping for a more heroic future. While the near professions such as nursing have established their discourses around culture, role and pedagogy, paramedics is still trying to chisel its identity. The myths of paramedic glories past tend to add to the confusion of graduates. Due to a lack of empirical studies of non-clinical aspects of paramedicine, a bricolage methodology was used to refresh data from two discrete qualitative research projects conducted in 2011. Both projects had originally been interested in optimal paramedic preceptorship before and after graduation, but neither had explored the implicit theme which revealed the role of rescue experiences in paramedic culture and identity. The bricolage included a new search of literature from near professions and applied new theoretical frameworks to the analysis of the extant data, to demonstrate how storytelling as an element of paramedic collegiality perpetuates rescue stories that are then used to define paramedic work.

  9. Subsurface application of manures slurries for conservation tillage and pasture soils and their impact on the nitrogen balance.

    Science.gov (United States)

    Dell, Curtis J; Meisinger, John J; Beegle, Douglas B

    2011-01-01

    Injection of cattle and swine slurries can provide soil incorporation in no-till and perennial forage production. Injection is expected to substantially reduce N loss due to ammonia (NH3) volatilization, but a portion of that N conservation may be offset by greater denitrification and leaching losses. This paper reviews our current knowledge of the impacts of subsurface application of cattle and swine slurries on the N balance and outlines areas where a greater understanding is needed. Several publications have shown that liquid manure injection using disk openers, chisels, or tines can be expected to Sreduce NH, emissions by at least 40%, and often by 90% or more, relative to broadcast application. However, the limited number of studies that have also measured denitrification losses have shown that increased denitrification with subsurface application can offset as much as half of the N conserved by reducing NH3 emissions. Because the greenhouse gas nitrous oxide (N2O) is one product of denitrification, the possible increases in N2O emission with injection require further consideration. Subsurface manure application generally does not appear to increase leaching potential when manure is applied at recommended rates. Plant utilization of conserved N was shown in only a portion of the published studies, indicating that further work is needed to better synchronize manure N availability and crop uptake. At this time in the United States, the economic and environmental benefits from reducing losses of N as NH3 are expected to outweigh potential liability from increases in denitrification with subsurface manure application. To fully evaluate the trade-offs among manure application methods, a detailed environmental and agricultural economic assessment is needed to estimate the true costs of potential increases in NO2O emissions with manure injection. PMID:21520742

  10. The Function of Warding off Evil of Folk Dress%民间服饰的辟邪功能

    Institute of Scientific and Technical Information of China (English)

    许平山; 郭小文; 宿伟

    2015-01-01

    The psychological orientation of warding off evil has a far- reaching influence on Chinese people’s clothing outlook,which embodied not only in the choice of clothing color,such as taking red as auspicious,taking black and white as fierce;it is also reflected in the choice of clothing materials,such as taking hemp clothing to avoid fierce,with thick texture clothing access to auspicious.Moreover,it is also re-flected in the selection of morphological diversity of jewelry and clothing,such as jade,tattoos,chisel teeth to ward off evil.The function of special evil with the folk dress is the specific national culture,social psy-chology and aesthetic taste.%趋吉避凶的心理取向,对中国人的服饰观,产生了深远的影响。这不仅体现于服装色彩的选择上,如以红色为吉,以黑、白色为凶;也体现于服装材质的选择上,如以麻服避凶,以质地粗厚服装趋吉;还体现在多样形态的服装饰物的选取与佩戴上,如佩玉、文身、凿齿等以辟邪。民间服饰所承载的特定的辟邪功能,是特定的民族文化、社会心理与审美情趣的外现。

  11. Contribution of macroporosity to water flux of a soil under different tillage systems

    Directory of Open Access Journals (Sweden)

    Carlos Germán Soracco

    2012-08-01

    Full Text Available In view of the importance of the macroporosity for the water transport properties of soils, its quantitative assessment is a challenging task. Measurements of hydraulic conductivity (K at different soil water tensions and the quantification of water-conducting macropores (θM of a soil under different tillage systems could help understand the effects on the soil porous system and related hydraulic properties. The purpose of this study was to assess the effects of Conventional Tillage (CT, Chisel Plow (CP and No Tillage (NT on θM and on K; and to quantify the contribution of macroporosity to total water flux in a loam soil. A tension disc infiltrometer was used at two soil water pressure heads (-5 cm, and 0 to infer θM and K, during fallow. Macroporosity was determined based on the flow contribution between 0 and -5 cm water potentials (K0, K5, respectively, according to the Hagen-Poiseuille equation. The K0 values were statistically higher for CT than for NT and CP. The K5 values did not differ statistically among treatments. The mean K values varied between 0.20 and 3.70 cm/h. For CT, θM was significantly greater than for CP and NT, following the same trend as K0. No differences in θM were detected between CP and NT. With CT, the formation of water-conducting macropores with persistence until post-harvest was possible, while under CP preparation, the water-conducting macropores were not persistent. These results support the idea that tillage affects the soil water movement mainly by the resulting water-conducting macropores. Future studies on tillage effects on water movement should focus on macroporosity.

  12. EFFECT OF SOIL TILLAGE AND PLANT RESIDUE ON SURFACE ROUGHNESS OF AN OXISOL UNDER SIMULATED RAIN

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    Elói Panachuki

    2015-02-01

    Full Text Available Surface roughness of the soil is formed by mechanical tillage and is also influenced by the kind and amount of plant residue, among other factors. Its persistence over time mainly depends on the fundamental characteristics of rain and soil type. However, few studies have been developed to evaluate these factors in Latossolos (Oxisols. In this study, we evaluated the effect of soil tillage and of amounts of plant residue on surface roughness of an Oxisol under simulated rain. Treatments consisted of the combination of the tillage systems of no-tillage (NT, conventional tillage (CT, and minimum tillage (MT with rates of plant residue of 0, 1, and 2 Mg ha-1 of oats (Avena strigosa Schreb and 0, 3, and 6 Mg ha-1 of maize (Zea mays L.. Seven simulated rains were applied on each experimental plot, with intensity of 60±2 mm h-1 and duration of 1 h at weekly intervals. The values of the random roughness index ranged from 2.94 to 17.71 mm in oats, and from 5.91 to 20.37 mm in maize, showing that CT and MT are effective in increasing soil surface roughness. It was seen that soil tillage operations carried out with the chisel plow and the leveling disk harrow are more effective in increasing soil roughness than those carried out with the heavy disk harrow and leveling disk harrow. The roughness index of the soil surface decreases exponentially with the increase in the rainfall volume applied under conditions of no tillage without soil cover, conventional tillage, and minimum tillage. The oat and maize crop residue present on the soil surface is effective in maintaining the roughness of the soil surface under no-tillage.

  13. Efficacy of various root canal irrigants on removal of smear layer in the primary root canals after hand instrumentation: A scanning electron microscopy study

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    Hariharan V

    2010-01-01

    Full Text Available Aim: The purpose of this in-vitro study is to determine the efficacy of various irrigants in removing the smear layer in primary teeth root canals after hand instrumentation. Materials and Methods: The present study consisted of 30 human primary incisors which were sectioned at the cementoenamel junction horizontally. The specimens were divided randomly into four experimental and one control group having six teeth each and each group was treated with the specific irrigant. 5.25% NaOCl, 5.25% NaOCl + 10% EDTA, 6% citric acid, 2% chlorhexidine, saline (control were the irrigants evaluated for efficacy in removal of smear layer. The specimens were split along the longitudinal axis using a chisel after placing superficial grooves in cementum not extending to the root canal. The exposed surface was subjected to scanning electron microscopic analysis to reveal the efficacy of irrigants in removal of smear layer. The representative areas were evaluated twice at 15 days interval by a single evaluator. The scale for the smear layer removal by Rome et al was modified and used in the present study. Results: The pictures from the scanning electron microscopy showed that among the tested irrigants, citric acid has the best efficacy to remove the smear layer without altering the normal dentinal structures, which was supported by the lowest mean smear scores. The pictures from the 10%EDTA + 5.25% sodium hypochlorite group showed that even though it removed the smear layer, it adversely affected the dentine structure. SEM pictures of the other groups like sodium hypochlorite, chlorhexidine revealed that these irrigants does not have the capacity to remove the smear layer in primary teeth. Conclusions: The results of the present study clearly indicate the superior efficacy of 6% citric acid than the other tested irrigants on removing the smear layer in primary teeth root canals.

  14. Identification of Gene Modules Associated with Low Temperatures Response in Bambara Groundnut by Network-Based Analysis.

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    Venkata Suresh Bonthala

    Full Text Available Bambara groundnut (Vigna subterranea (L. Verdc. is an African legume and is a promising underutilized crop with good seed nutritional values. Low temperature stress in a number of African countries at night, such as Botswana, can effect the growth and development of bambara groundnut, leading to losses in potential crop yield. Therefore, in this study we developed a computational pipeline to identify and analyze the genes and gene modules associated with low temperature stress responses in bambara groundnut using the cross-species microarray technique (as bambara groundnut has no microarray chip coupled with network-based analysis. Analyses of the bambara groundnut transcriptome using cross-species gene expression data resulted in the identification of 375 and 659 differentially expressed genes (p<0.01 under the sub-optimal (23°C and very sub-optimal (18°C temperatures, respectively, of which 110 genes are commonly shared between the two stress conditions. The construction of a Highest Reciprocal Rank-based gene co-expression network, followed by its partition using a Heuristic Cluster Chiseling Algorithm resulted in 6 and 7 gene modules in sub-optimal and very sub-optimal temperature stresses being identified, respectively. Modules of sub-optimal temperature stress are principally enriched with carbohydrate and lipid metabolic processes, while most of the modules of very sub-optimal temperature stress are significantly enriched with responses to stimuli and various metabolic processes. Several transcription factors (from MYB, NAC, WRKY, WHIRLY & GATA classes that may regulate the downstream genes involved in response to stimulus in order for the plant to withstand very sub-optimal temperature stress were highlighted. The identified gene modules could be useful in breeding for low-temperature stress tolerant bambara groundnut varieties.

  15. Resistência à penetração e rendimento da soja após intervenção mecânica em latossolo vermelho sob plantio direto Penetration resistance and soybean yield after mechanical intervention on an oxisol under tillage

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    Marta Sandra Drescher

    2012-12-01

    íveis alocados na subparcela foram constituídos pela ação de uma semeadora de plantio direto equipada com discos duplos defasados atuando até 7 cm de profundidade e de uma semeadora equipada com discos duplos + haste atuando até 13 cm de profundidade. Os resultados obtidos indicaram que a intervenção mecânica em solo manejado sob SPD consolidado, mediante a prática de escarificação ou aração do solo, apresenta potencial efêmero para mitigar a compactação e promover a melhoria da estrutura do solo, com efeito residual de até dois anos e meio para a resistência do solo à penetração. A utilização de semeadora de plantio direto equipada com sulcador tipo haste + disco apresentou potencial para mitigação da compactação do solo, promovendo a redução da resistência mecânica do solo à penetração na camada de 7 - 15 cm de profundidade. Contudo, o efeito residual da intervenção mecânica para descompactação do solo e a adoção dos diferentes dispositivos de aplicação do adubo no sulco de semeadura não foram eficientes em alterar o rendimento de grãos da cultura da soja na safra agrícola 2008/2009.Compaction negatively affects a number of soil properties, e.g., resistance to root penetration and water and nutrient availability to plants, restricting the photosynthetic rate, shoot growth and consequently, the yield. When soil compaction becomes limiting to crop development, mitigation measures must be adopted. The purpose of this study was to evaluate the residual effect of mechanical soil plowing and chiseling, by a seeder with soil breakers (disks and disks plus short ripper as mitigation practice of the soil compaction under no-tillage (NT, on soil penetration resistance and soybean yield. In 2001, a study was conducted in Coxilha, in northern Rio Grande do Sul, on an Oxisol, in an area with a sequence of NT management. In this field, every year a treatment of mechanical soil decompression was applied, consisting of plowing and chiseling the

  16. To Evaluate the Efficacy of an Innovative Irrigant on Smear Layer Removal – SEM Analysis

    Science.gov (United States)

    Sukumaran, Vridhachalam Ganapathy; Subbiya, Arunajatesan

    2016-01-01

    Introduction The goal of endodontic therapy is to completely eliminate the microorganisms and the smear layer from the root canal in order to provide a good seal of the root filling materials. Aim The aim of this study was to find a viable alternative irrigant, which is easily available with less erosion and clinically acceptable smear layer removal by comparing the efficacy of EDTA and commercially available super-oxidized water, named Oxum, as a final rinse on smear layer removal and erosion in relation to coronal, middle and apical thirds of radicular dentin using Scanning Electron Microscope (SEM) analysis. Materials and Methods Freshly extracted 30 human lower second premolar teeth with straight roots and type I canal anatomy were selected. The root canals were cleaned and shaped using Universal Protaper Rotary System. Irrigation was performed with 1 ml of 2.5% of NaOCl solution after each instrument change. The final irrigation (5 ml) sequence was as follows: Group I- 17% EDTA, Group II – OXUM, and Group III - 0.9% saline (control) for one minute. Then, the root canals were finally irrigated with 5ml of distilled water to remove any precipitate. The roots were then gently split into two halves using a chisel and subjected to SEM analysis. Results The SEM photomicrographs were evaluated by two independent examiners and Mann Whitney results showed that there was no statistically significant difference between the two examiners. Non-parametric statistical analysis of all experimental groups showed significant difference between coronal, middle and apical third for smear layer removal with p-value<0.05. For erosion, in group II (oxum) showed statistically significant difference between coronal, middle and apical third and it showed significantly less dentine erosion when compared to EDTA. Conclusion Within the limitations of the present study, Oxum the commercially available super-oxidized water proved to be equally effective in smear layer removal with less

  17. Osteomas of the middle ear

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    Sente Marko

    2004-01-01

    Full Text Available INTRODUCTION Osteomas of the middle ear are small, single, usually unilateral, peduncular growths, off-white in color, with smooth or multilobular surface, asymptomatic or causing functional disorders (progressive hearing loss, pathological appearance of the eardrum, vertigo and otorrhea, of unclear or unknown etiology. Fleury described three types of osteomas: massive, diffuse atticoantral and localized type. The therapy is surgical. Small and asymptomatic ones are followed-up. Cremers suggests surgical intervention in cases of progressive growth and increased hearing loss. Case description Discharge and pain in the left ear started twelve years ago, accompanied by impaired hearing and tinnitus. Four months ago the symptoms aggravated and discharge and pain increased. Otomicroscopic findings revealed: perforation in the posterior attic and a prominent polypous, clustered bright red formation. Schüller X-ray showed total absence of pneumocyte cells, with distinct sclerotic changes. Retroauricular access showed a biventricular bony formation in the cavum and partly in the antrum. A cholesteatoma extended from the cavum into the antrum, above the osteatoma. The bony formation was separated transmeatally from the grip in the posterior attic using a chisel, partially removing the bone wall of the exterior aural tube, removing it completely through the mastoid antrum. The removed bony mass, sized 5 x 8 x 8 mm, included also the incus. DISCUSSION Osteoma was discovered accidentally. Regarding clinical features, it belonged to the second group, due to progressive hearing loss, recurrent episodes of otorrhea, pain, biventricular shape and association with cholesteatoma. It was removed using a combined method. It was not possible to establish when the osteoma exactly started generating. It is possible that the initial complaints twelve years ago were the first signs of illness, and chronic otitis may have occurred as a consequence of the tumor.

  18. [Vibration hazards in quarry workers].

    Science.gov (United States)

    Sakakibara, H; Miyao, M; Nakagawa, T; Yamada, S; Kobayashi, F; Ono, Y; Iwata, M; Hisanaga, N; Momoi, N

    1984-03-01

    Vibration hazards were surveyed in a population of quarry workers using chipping hammers and to a lesser extent, rock drills. Sixty-nine male quarry workers, aged 49.1 +/- 8.7 and exposed to vibration for 16.4 +/- 5.1 years, were surveyed in 1981-82. They were exposed to vibration for about 2-4 hours per days, mainly under a piece-work pay system. They had a high prevalence of Raynaud's phenomenon (36.2%) and numbness in upper extremities (53.6%). It is considered that the high prevalence was mainly due to large vibration levels in chipping hammers and rock drills and long daily exposure time. The attacks of Raynaud's phenomenon were found predominantly in the left hand, which held chisels, whereas the restriction of motion in the elbow was predominantly in the right arm which pushed chipping hammers. The same 49 male quarry workers in this population were also surveyed in 1976-77 and the prevalence of their complaints between 1976-77 and 1981-82 was compared. The prevalence of Raynaud's phenomenon was the same, but the frequency of the attacks increased between the two periods. The prevalence of other complaints such as numbness, pain and chills in the upper extremities also increased. Between 1976-77 and 1981-82, the prevalence of Raynaud's phenomenon, numbness, and pain in the upper extremities increased in the population of quarriers exposed to vibration for above 2.6 hours per day and 200 days per year, or 600 hours per year. On the other hand, the prevalence of these complaints mostly decreased in the population of quarriers with less exposure.

  19. Artifak Purba Pasemah: Analisis Ungkap Rupa Patung Megalitik di Pasemah

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    Erwan Suryanegara

    2007-03-01

    Full Text Available Prehistoric relics, especially those of megalithic traditions, were found many in the plateau of Pasemah. From several types of megalithic artefacts, megalithic idols are the one that excessively found in Pasemah. Unfortunately, scientific information about these ancient artefacts in Pasemah is still scarcely to be found, especially in the form of visual data and reports. Based upon this notion, this research conducted a study to investigate, document and describes the existence, depiction, the object, expression style, symbol, and attribute of the megalithic idols of Pasemah; using the approach of ungkap rupa. The study discovers that the proponent society of megalithic culture in Pasemah had used and applied bronze. They had good ability in chiseling idols from big stones of andesit, formed it in sharp corners and created accurate forms. The depicted idols show that its form has a dynamic pictorial postures and shapes, although some are also made in the style of realistic expression. The idols are formed in a leaning forwards posture, its head or face tilted upward, and its feet usually visualized in the bended forms, depicting austronesoid man and animals complete with its attribute and symbols. Further, the study indicates that these megalithic idols were representations of symbolic-mystical beliefs of a Pasemah’s society which were based on cosmology of the past. Accordingly, these idols were inseparable parts of Pasemah’s ancestor veneration rituals. The distinctiveness of these idols is found in their dynamics—both in pictorial and realistic depiction— that seem to be the masterpiece of megalithic idols of Pasemah at that time. The idols visualize the complete body part of austronesoid man and/or animals (head, body, foot/feet, and hand, which indicates that the megalithic idols of Pasemah represents a mystical culture of a society that whorshiped the spirit of their ancestors, live as an agrarist society of farmer (peladang

  20. Incidence & Prevalence of Silicotuberculosis in Western Rajasthan: A Retrospective Study of Three Years

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    Kulbeer Chopra, Prabhu Prakash, Suman Bhansali, Arvind Mathur, P K Gupta

    2012-01-01

    Full Text Available Silicosis is a form of pneumoconiosis. It results from inhalation of dust containing crystalline Silica particles of size 0.5 - 5 microns in diameter. Prevalence of Pulmonary Tuberculosis in Silicotics is more common when compared to prevalence in general population. This entity is called Silico-tuberculosis. Study was conducted in Kamla Nehru Chest Hospital attached with Dr.SNMC Jodhpur, among 300 stone mine workers of sand stone mines of Jodhpur with clinico-radiological evidence of Silico-tuberculosis. Workers were divided into 3 categories cutter / driller involved in blasting and cutting stones, dresser engaged in fine work by chisel and Labourer - Loading and Unloading of Stones in Mines .All studied patients were males, majority of cases belong to 21-55 years (93% age group. Among these cases maximum no. of patients belong to 46-50 yr. (18% age group. This is the most economically productive age group in India. With increase in duration of exposure from (0-20 years to Silica particles there is increase in the no. of silico-tuberculosis. After 20 year of exposure there is decrease in no. of cases because cases do not survive upto that long period. 137 patients out of 300 cases were confirmed Acid Fast Bacilli positive by smear examination. 123 patients out of 300 cases were bacteriologically confirmed by culture. Out of 123 culture positive cases 66 (53.65% were typical Mycobacteria& 57 (46.34% were Atypical Mycobacterium. M. Kansasii(28, M. Scrofulaceum ( 9 ,M. Ulcerans(1 M. Fortuitum ( 19, When radiological pattern of Typical Mycobacteria cases and Atypical Mycobacterial cases were confirmed compared we found that Cavity with Nodulation, Pleural Reaction, Progressive Massive Fibrosis, Lower Lobe Involvement, Pnemothorax they all were more common in Atypical than Typical Mycobacteria. M.Kansasii predominantly grown in mining area all around the world. Prevalence of Pulmonary Tuberculosis in Silicotics is more common when compared to

  1. ARROZ DE TERRAS ALTAS EM ROTAÇÃO COM SOJA UPLAND RICE IN ROTATION WITH SOYBEAN

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    Cleber Morais Guimarães

    2007-09-01

    upland rice grown in soils of continued soybean cultivation, under different tillage systems and nutrient doses, and the effects of these treatments on the subsequent soybean yield. The treatments were three doses of macronutrients (zero, 100 kg.ha-1, and 300 kg.ha-1 of commercial formula 4-30-16, without or with micronutrient fertilization (20 kg.ha-1 of zinc sulfate, 50 kg.ha-1 of FTE BR 12, and 50 kg.ha-1 of iron sulfate. The experiments were carried out under three soil tillage systems (heavy disk harrow, chisel plow, and moldboard plow. A joint analysis showed that the moldboard plow system provided average rice grain yield of 3077 kg.ha-1, 9% and 26% higher than those of chisel plow (2823 kg.ha-1, and heavy disk harrow (2440 kg.ha-1, respectively. Macro and micronutrient treatments did not significantly affect rice grain yield. The different soil tillage systems and nutrient doses applied to rice crop did not significantly affect soil macro and micronutrient levels and pH, nor did it affect the soybean yield when the crop was planted in the same area in the succeeding year. Average soybean yield was approximately 2600 kg.ha-1. As far as profitability and sustainability are concerned, it was recommended that rice grown after soybean crop, under moldboard plowing, should be fertilized with 100 kg.ha-1 of commercial formula 4-30-16, without micronutrient fertilization.

    KEY-WORDS: Moldboard plow; chisel plow; heavy disk harrow; macronutrient; micronutrient.

  2. Early Clinical Effectiveness of ER:Yag Laser in Association with the Red Complex of Bacteria in the Initial Treatment of Moderate Chronic Periodontitis

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    Yaneva Bl.

    2014-06-01

    Full Text Available Chronic periodontitis is a result of polymicrobial infection and its treatment aims removal of dental calculus and biofi lm from the periodontal pocket. Many hand and power-driven instruments are created for this purpose. In recent years, lasers are widely discussed tools for periodontal therapy. The aim of the present study is to evaluate the early microbiological and clinical effectiveness of the Er:YAG laser in the treatment of chronic periodontitis. 30 patients with moderate chronic periodontitis were enrolled in the study. Using a split-mouth design they were treated either with Er:YAG laser (chisel tip, 100 mJ, 15 Hz, 5-6 water spray-test group or with Gracey curettes- control group. Probing pocket depth (PPD, gingival recession (GR, clinical attachment level (CAL, bleeding on probing and plaque presence were evaluated at baseline and one month after the therapy. Microbiological samples were taken from the deepest four pockets of each quadrant from 20 randomly selected patients (n = 80. They were evaluated using real time PCR for periodontal pathogens from the red complex (Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia. One month after therapy in the control group PPD decreased from 4.59 mm to 3.36 mm, the CAL gain was 1.09 mm and the reduction of bleeding and plaque - from 87.9% to 33.7% and from 75.9% to 40.9%, respectively. In the test group PPD decreased from 4.58 mm to 3.15 mm, the CAL gain was 1.37mm and the reduction of bleeding and plaque was from 85.6% to 25.9% one month after the treatment. The results were statistically significant in favour of the laser group (p < 0.05. Microbiological analysis revealed that the pathogens from the red complex decreased 3 times in the control and 6 times in the test group. Therefore, the Er:YAG laser demonstrate pronounced early effectiveness in chronic periodontitis treatment and would be appropriate alternative of the conventional periodontal therapy.

  3. Desempenho de um trator em função do tipo de pneu, da lastragem e da velocidade de trabalho Performance of an tractor as a function of tire type, ballasting and forward speed

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    Afonso Lopes

    2005-04-01

    Full Text Available O trabalho comparou o desempenho de um trator agrícola 4x2 TDA de 89 kW (121cv em função do tipo de pneus (radial, diagonal e de baixa pressão, a condição de lastragem (com e sem água nos pneus e quatro velocidades [V1 (1,84km h-1, V2 (3,18km h-1, V3 (4,57km h-1, V4 (5,04km h-1]. O experimento foi realizado na UNESP-Jaboticabal-SP, em condição de preparo do solo com escarificador de sete hastes a 30cm de profundidade. Os pneus foram do tipo R1, com as seguintes características: [radial (dianteiros-14.9 R 26; traseiros-620/75 R 30 diagonal (dianteiros-14.9-26, traseiros-23.1-30 e BPAF (dianteiros-500/60-26.5; traseiros-700/55-34]. O delineamento experimental foi blocos casualizados, em esquema fatorial 3x2x4, com 24 tratamentos e três repetições. Os resultados evidenciaram vantagens para o trator equipado com pneus radiais.The objective of this study was to compare the performance of the FWD agricultural tractor, equipped with three types of tires (bias ply, radial and low pressure, with and without tire water ballasting, operating in four forward speed. The research was carried out at UNESP, SP, Brazil, with the tractor pulling a chisel plow. A tractor with 89kW (121cv engine power equipped with FWD, was used in the experiment, and the tires used had the following characteristics: radial (front: 14.9R26 and rear: 620/75R30, bias ply (front: 14.9-26 and rear: 23.1-30 and low pressure (front: 500/60-26.5 and rear: 700/55-34. The experiment was conducted in a completely randomized block, design (3x2x4, with 24 treatments and three replications. The results evidenced advantages for the tractor equipped with radial tires.

  4. Set Free by Tragedy

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    G.yang mtsho skyid

    2013-12-01

    Full Text Available I was born in a rural community – Hor Village, Tsho drug (Cuozhou Township, Gcan tsha (Jianzha County, Qinghai Province, China. I graduated from Qinghai Normal University with a BA in English and Tibetan and then found my current job, teaching English at Jianzha County Number One Nationalities' Middle School. I enjoy writing stories because I think they explore social phenomena in ways that other writing can not. This story is based on a traditional Tibetan woman's life who married according to her parents' arrangement. When struck by disaster, she was first helpless, but eventually broke with tradition and achieved success, creating a comfortable life for herself and her family. The winter sky was gray and windy. The village was wrapped in the faint smoke that poured from the chimneys of each house. The Yellow River was very blue and calm, even though a harsh wind blew across it. Despite the bad weather, I was excited and couldn't wait to visit Gang skyid from my village, Hor. Gang skyid wasn't famous, beautiful, or rich. She was a farmer, but her life experiences were worth recording and sharing. I was full of expectations when I went to her home to interview her, but she wasn't there. She was in the ma Ni room, so I immediately went there. When I arrived, she was sitting in the sun, spinning a big prayer wheel by pulling a thick, old rope together with other elder women. They were holding the rope tightly as their hands moved up and down rhythmically. Tugged in this way, the huge prayer wheel rotated slowly in front of the women, as though demonstrating the eternal nature of samsara. Gang skyid nodded slightly and thoughtfully when I asked if I could interview her. I sat down by her with a thankful face and realized her eyes were brimming with tears. I felt my throat become dry as I gazed at her. Her face creased as she closed her eyes, and tears ran down her cheeks. Wrinkles were deeply chiseled in her face, especially her forehead. I

  5. FY 2016 Status Report: CIRFT Testing Data Analyses and Updated Curvature Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Hong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-01

    This report provides a detailed description of FY15 test result corrections/analysis based on the FY16 Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT) test program methodology update used to evaluate the vibration integrity of spent nuclear fuel (SNF) under normal transportation conditions. The CIRFT consists of a U-frame testing setup and a real-time curvature measurement method. The three-component U-frame setup of the CIRFT has two rigid arms and linkages to a universal testing machine. The curvature of rod bending is obtained through a three-point deflection measurement method. Three linear variable differential transformers (LVDTs) are used and clamped to the side connecting plates of the U-frame to capture the deformation of the rod. The contact-based measurement, or three-LVDT-based curvature measurement system, on SNF rods has been proven to be quite reliable in CIRFT testing. However, how the LVDT head contacts the SNF rod may have a significant effect on the curvature measurement, depending on the magnitude and direction of rod curvature. It has been demonstrated that the contact/curvature issues can be corrected by using a correction on the sensor spacing. The sensor spacing defines the separation of the three LVDT probes and is a critical quantity in calculating the rod curvature once the deflections are obtained. The sensor spacing correction can be determined by using chisel-type probes. The method has been critically examined this year and has been shown to be difficult to implement in a hot cell environment, and thus cannot be implemented effectively. A correction based on the proposed equivalent gauge-length has the required flexibility and accuracy and can be appropriately used as a correction factor. The correction method based on the equivalent gauge length has been successfully demonstrated in CIRFT data analysis for the dynamic tests conducted on Limerick (LMK) (17 tests), North Anna (NA) (6 tests), and Catawba mixed oxide (MOX

  6. 下颌第三磨牙阻生拔除临床探讨100例%To Investigate the Clinical 100 Cases of Mandibular Impacted Tooth Extraction

    Institute of Scientific and Technical Information of China (English)

    王新波; 林振梅; 梁源

    2016-01-01

    Objective To investigate the matters needing attention in design and operation process of extraction of mandibular impacted tooth extraction in.Methods 100 cases of patients undergoing mandibular impacted tooth extraction, for the following operation: the incision split crown and method. Method of turbine. The incision, combined with bone chisel.Results All patients were successfully removed, with the time of 20-65min, the average 35min, conventional surgery postprocessing were cured. After extraction of infection in 3 cases, dry socket in 2 cases, 3 cases of lower lip temporary numbness, without mandibular fracture.Conclusion Extraction of mandibular impacted tooth is a complicated operation, removal of front will do a good job in patients with systemic and local examination, X-ray film, do a good job of impacted tooth type, and formulating measures to deal with the detailed operation plan and operation complications.%目的:探讨下颌第三磨牙阻生拔除的手术设计和拔除过程中的注意事项。方法选择100例需行下颌第三磨牙阻生齿拔除的患者,行下列手术:①切开劈冠挺拔法。②涡轮机分牙法。③切开、劈冠联合去骨法。结果所有患者均能顺利拔除,用时20-65min,平均35min,常规术后处理均痊愈。拔牙后出现感染3例,干槽症2例,下唇暂时性麻木3例,未出现下颌骨骨折。结论下颌第三磨牙阻生拔除是一项比较复杂的手术,拔除前一定做好患者全身以及局部检查,拍摄X线片,做好阻生齿临床分型,制定详实的手术方案和术中并发症的应对措施。

  7. Single Piezo-Actuator Rotary-Hammering Drill

    Science.gov (United States)

    Sherrit, Stewart; Bao, Xiaoqi; Badescu, Mircea; Bar-Cohen, Yoseph

    2011-01-01

    This innovation comprises a compact drill that uses low-axial preload, via vibrations, that fractures the rock under the bit kerf, and rotates the bit to remove the powdered cuttings while augmenting the rock fracture via shear forces. The vibrations fluidize the powered cuttings inside the flutes around the bit, reducing the friction with the auger surface. These combined actions reduce the consumed power and the heating of the drilled medium, helping to preserve the pristine content of the produced samples. The drill consists of an actuator that simultaneously impacts and rotates the bit by applying force and torque via a single piezoelectric stack actuator without the need for a gearbox or lever mechanism. This reduces the development/fabrication cost and complexity. The piezoelectric actuator impacts the surface and generates shear forces, fragmenting the drilled medium directly under the bit kerf by exceeding the tensile and/or shear strength of the struck surface. The percussive impact action of the actuator leads to penetration of the medium by producing a zone of finely crushed rock directly underneath the struck location. This fracturing process is highly enhanced by the shear forces from the rotation and twisting action. To remove the formed cuttings, the bit is constructed with an auger on its internal or external surface. One of the problems with pure hammering is that, as the teeth become embedded in the sample, the drilling efficiency drops unless the teeth are moved away from the specific footprint location. By rotating the teeth, they are moved to areas that were not fragmented, and thus the rock fracturing is enhanced via shear forces. The shear motion creates ripping or chiseling action to produce larger fragments to increase the drilling efficiency, and to reduce the required power. The actuator of the drill consists of a piezoelectric stack that vibrates the horn. The stack is compressed by a bolt between the backing and the horn in order to

  8. The effect of collagen removal on shear bond strength of four single bottle adhesive systems

    Directory of Open Access Journals (Sweden)

    Kasraie Sh

    2006-07-01

    Full Text Available Background and Aim: Achieving adhesion between restorative materials and dentin as a wet and dynamic surface is an important topic in restorative and especially in conservative dentistry. Adhesion of new dentin bonding systems depends on the formation of hybrid layer and micromechanical retention. Nevertheless, an ideal adhesive system has not yet been introduced .Recent studies reveal an increase in bonding stability when the collagen is removed from demineralized dentin surfaces. This study investigates the effect of collagen removal on the shear bond strength of four single bottle dentin bonding systems regarding their structural differences. Materials and Methods: This experimental study was performed on 56 intact human premolar teeth. Smooth surfaces of dentin were prepared on buccal & lingual aspects of teeth, providing 112 dentin surfaces. The dentin surfaces were etched with 37% phosphoric acid for 15 seconds and then rinsed. The specimens were divided into 8 groups. Single bottle adhesive systems [Single Bond (3M, One-Step (Bisco, Prime & Bond NT (Dentsply, and Excite (Vivadent] were then applied on the dentin surfaces of 4 groups using the wet bonding technique. In the other 4 groups, the demineralized dentin surfaces were treated with a 5.25% solution of sodium hypochlorite for one minute in order to remove the surface organic components. The adhesive systems mentioned before were applied to these 4 groups with the same wet bonding technique. A cylinder of Z100 (3M dental composite with a 3 mm diameter and 2 mm height was placed on the adhesive covered dentin surface of all groups and light-cured (400 mW/cm2 ,40 sec on each side. The specimens were kept in distilled water at room temperature for one week and then thermocycled for 3000 times (5-55 oc. Shear bond strength of specimens was measured using an Instron (1495 universal mechanical testing machine with cross-head speed of 0.5 mm/minute and chisel form shearing blade. Data were

  9. Distribution of organic carbon in physical fractions of soils as affected by agricultural management

    Energy Technology Data Exchange (ETDEWEB)

    Sindhu, Jagadamma [Oak Ridge National Laboratory (ORNL); Lal, Dr. Rattan [Ohio State University, The, Columbus

    2010-08-01

    Soil organic carbon (SOC) is distributed heterogeneously among different-sized primary particles and aggregates. Further, the SOC associated with different physical fractions respond differently to managements. Therefore, this study was conducted with the objective to quantify the SOC associated with all the three structural levels of SOC (particulate organic matter, soil separates and aggregate-size fractions) as influenced by long-term change in management. The study also aims at reevaluating the concept that the SOC sink capacity of individual size-fractions is limited. Long-term tillage and crop rotation effects on distribution of SOC among fractions were compared with soil from adjacent undisturbed area under native vegetation for the mixed, mesic, Typic Fragiudalf of Wooster, OH. Forty five years of no-till (NT) management resulted in more SOC accumulation in soil surface (0 7.5 cm) than in chisel tillage and plow tillage (PT) treatments. However, PT at this site resulted in a redistribution of SOC from surface to deeper soil layers. The soils under continuous corn accumulated significantly more SOC than those under corn soybean rotation at 7.5 45 cm depth. Although soil texture was dominated by the silt-sized particles, most of the SOC pool was associated with the clay fraction. Compared to PT, the NT treatment resulted in (i) significantly higher proportion of large macroaggregates (>2,000 m) and (ii) 1.5 2.8 times higher SOC concentrations in all aggregate-size classes. A comparative evaluation using radar graphs indicated that among the physical fractions, the SOC associated with sand and silt fractions quickly changed with a land use conversion from native vegetation to agricultural crops. A key finding of this study is the assessment of SOC sink capacity of individual fractions, which revealed that the clay fraction of agricultural soils continues to accumulate more SOC, albeit at a slower rate, with progressive increase in total SOC concentration

  10. Consumo de combustível na operação de subsolagem realizada antes e depois de diferentes sistemas de preparo periódico do solo Fuel consumption in the subsoiling operation accomplished before and after different preparation systems of periodic soil tillage

    Directory of Open Access Journals (Sweden)

    Nilson Salvador

    2008-06-01

    Full Text Available A subsolagem tem aumentado nos últimos anos de forma indiscriminada, faltando estudos que norteiem os melhores procedimentos para que novos problemas não sejam acrescentados devido a subsolagens inadequadas ou mesmo em solos onde a operação é desnecessária, e principalmente buscar redução no consumo de combustível. Dessa forma, este trabalho teve o objetivo de avaliar o consumo de combustível na operação de subsolagem efetuada antes e depois de diferentes sistemas de preparo periódico do solo, classificado como Nitossolo Vermelho distroférrico. Os preparos foram realizados com arado de discos, arado de discos mais uma gradagem de nivelamento, grade pesada, grade pesada mais gradagem de nivelamento e escarificador. A realização da subsolagem depois dos sistemas de preparo periódico requereu 15% menos de potência na barra de tração. A subsolagem depois dos diferentes sistemas de preparo economizou 16,5% de combustível por área. O deslizamento das rodas motrizes e a velocidade média operacional obtiveram melhor desempenho quando se realizou a subsolagem depois do preparo do solo.The subsoiling has had a great increase in the last few years, but there is still a lack of studies that guide the best procedures so that new problems do not appear because of inadequate subsoiling or even in soil where the same operation is unnecessary, and primarily look for a reduction in the consumption of fuel. Thus, this work had the objective of evaluating the fuel consumption in the operation of subsoiling performed before and after different systems of preparation of a regular land classified as Nitossolo Red Distroférrico. The periodic tillage systems were: plowing with disks, plowing with disks followed by one leveling, plowing harrow, plowing harrow followed by leveling and chiseling. The accomplishment of the subsoiling after the preparation of periodic systems required 15% less power in the bar of traction. The subsoiling after the

  11. Variscita y ámbar en el Neolítico gallego. Análisis arqueométrico del collar del túmulo 1 de Chousa Nova, Silleda (Pontevedra, España

    Directory of Open Access Journals (Sweden)

    Domínguez-Bella, Salvador

    2011-12-01

    Full Text Available The excavation of barrow 1 of Chousa Nova, Silleda, Pontevedra (NW Spain offered surprising results. This mound, in spite of experiencing a large number and types of anthropic damage, still preserved a great constructive complexity. Within its megalithic chamber, formed by 5 granite orthostats and a large roofing slab of, also in granite, a set of archaeological materials appeared. These were an axe, a chisel and a polishing stone, with a set of 35 beads, most of them of a green stone and the rest of an organic material, with an extremely high degree of alteration, inserted between them. The analytical techniques have been in all cases not-destructives (X-ray diffraction and fluorescence spectroscopy, infrared spectroscopy, optical microscopy and environmental electronic microscopy, with microanalysis. The archaeometric analysis results show a mineralogical nature of these materials, based in variscite and amber. The textural and compositional features are very homogeneous between each assemblage of beads. The importance of the alteration phenomena and dissolution of the archaeological objects are determined and quantified. This alteration is due to an intense chemical attack during the burial periods. The possible source areas of provenance for these materials are also discussed on the basis of geochemical data obtained in the analysis.

    La excavación del túmulo 1 de Chousa Nova, Silleda (Pontevedra, proporcionó unos resultados sorprendentes. Aunque muy deteriorado, por diferentes factores, conservaba evidencias de una gran complejidad constructiva. Dentro de su cámara megalítica apareció, junto con otros objetos pulidos, un conjunto de 35 cuentas dispuestas a modo de collar. Se han estudiado todas, unas de color verde y otras de carácter orgánico, intercaladas entre ellas. Los resultados del análisis arqueométrico mediante técnicas no-destructivas (difracción y fluorescencia de Rayos X, espectroscopía de infrarrojos

  12. Integrated Palmer Amaranth Management in Glufosinate-Resistant Cotton: II. Primary, Secondary and Conservation Tillage

    Directory of Open Access Journals (Sweden)

    Michael G. Patterson

    2013-01-01

    Full Text Available A three year field experiment was conducted to evaluate the role of soil inversion, cover crops and spring tillage methods for Palmer amaranth between-row (BR and within-row (WR management in glufosinate-resistant cotton. Main plots were two soil inversion treatments: fall inversion tillage (IT and non-inversion tillage (NIT. Subplots were three cover treatments: crimson clover, cereal rye or none (i.e., winter fallow; and the sub subplots were four secondary spring tillage methods: disking followed by (fb cultivator (DCU, disking fb chisel plow (DCH, disking fb disking (DD and no tillage (NT. Averaged over years and soil inversion, the crimson clover produced maximum cover biomass (4390 kg ha−1 fb cereal rye (3698 kg ha−1 and winter fallow (777 kg ha−1. Two weeks after planting (WAP and before the postemergence (POST application, Palmer amaranth WR and BR density were two- and four-times less, respectively, in IT than NIT. Further, Palmer amaranth WR and BR density were reduced two-fold following crimson clover and cereal rye than following winter fallow at 2 WAP. Without IT, early season Palmer amaranth densities were 40% less following DCU, DCH and DD, when compared with IT. Following IT, no spring tillage method improved Palmer amaranth control. The timely application of glufosinate + S-metolachlor POST tank mixture greatly improved Palmer amaranth control in both IT and NIT systems. The highest cotton yields were obtained with DD following cereal rye (2251 kg ha−1, DD following crimson clover (2213 kg ha−1 and DD following winter fallow (2153 kg ha−1. On average, IT cotton yields (2133 kg ha−1 were 21% higher than NIT (1766 kg ha−1. Therefore, from an integrated weed management standpoint, an occasional fall IT could greatly reduce Palmer amaranth emergence on farms highly infested with glyphosate-resistant Palmer amaranth. In addition, a cereal rye or crimson clover cover crop can effectively reduce early season Palmer

  13. 住宅楼发生火灾后的鉴定及加固%Identiifcation and reinforcement of a residential building after the ifre

    Institute of Scientific and Technical Information of China (English)

    殷占忠; 孙源; 王立功

    2016-01-01

    通过对建筑物烧损构件表观现象进行观察,用回弹法检测混凝土构件的碳化深度和混凝土强度,用超声法检测损伤层厚度,使用钢筋位置测定仪对其钢筋数量与保护层厚度进行了检测,根据《火灾后建筑结构鉴定标准》对检测数据进行了分析,对在火灾中烧损的钢筋混凝土梁、柱、楼板和剪力墙进行了烧损等级的评定,以鉴定评定等级为依据,利用对原过火面积剔凿损伤层后采用高强聚合物砂浆修复、外粘型钢加固、粘碳纤维布加固的加固方法对损伤构件进行了补强处理,经过最后的计算发现结构的强度达到了国家标准所规定的设计强度,满足加固的要求。%Through observing the superficial phenomenon of burning building constructional element,testing the carbonation depth and the concrete strength of concrete members with the springback method, detecting damage layer thickness with ultrasound method,testing the quantity of rebar and cover to reinforcement by using reinforcement location tester, according to “the Appraisal Standard of Building Structure After Fire”,we analyzed the test data,evaluated the loss in the fire of the reinforced concrete beam, column,floor and shear wall in the damage grade,and based on the appraisal ratings,repaired with the high strength polymer mortar after the damage layer of the original burning area was chiseled,then sticked steel reinforcement,and sticked carbon fiber cloth reinforce reinforcing method for reinforcement treatment for the injury structural members.Through the final calculation,we found the strength of the structure has reached the national standard of design strength,which met the requirements of the reinforcement.

  14. Research on abrasion resistance technique for sinter single-roll crusher%烧结矿单辊破碎机抗磨损技术研究

    Institute of Scientific and Technical Information of China (English)

    陈方述; 聂松辉; 周卓林

    2011-01-01

    Sinter single-roll crusher is an important component of the sinter production line ,which operating environment and nature decides that it must possess properties of high-temperature resistance and abrasion resistance.First the invalid reasons and abrasive wear mechanism are studied aim at the problems of easy worn and short service life of the single-roll crusher.A conclusion is made that the abrasion pattern is abrasive wear happens under high-temperature environment with forms of chiseling and cutting.Then a structural design with abrasion resistance is studied ,simultaneously its materials selection and hardfacing technics are also analyzed and discussed.Afterwards ,one single-roll crusher with characteristics of long service life and abrasion resistance is designed.which is proved in the engineering practice that the proposed anti-wear technology for single-roll crusher is viable and effective.%单辊破碎机是烧结矿生产线上一个重要的部件,其工作环境与性质决定其必须具有抗高温与耐磨损的特性.针对目前单辊破碎机易磨损、寿命短的问题,首先,对其失效原因与磨损机理等方面进行了研究,得出其主要磨损形式是高温环境下带有凿削形式磨损的磨粒磨损.然后,研究了其抗磨损结构设计的方法,并对其材料选择与耐磨堆焊工艺等进行了详细分析与探讨,设计了一种抗磨损的长寿命烧结矿单辊破碎机.最后,通过工程实际使用验证了提出的单辊破碎枳抗磨损技术是可行且有效的.

  15. Clinical Use of Minimally Invasive Techniques in Extraction of Mandibular First Molar%微创技术在拔除下颌第一磨牙中的应用

    Institute of Scientific and Technical Information of China (English)

    何世海; 李蓓

    2014-01-01

    Objective:To evaluate the superiority of the minimally invasive technology applying in ex-traction of mandibular first molar .Method:126 patients who required having the mandibular first molar ex-tracted were randomly assigned to two groups in this study .Tooth extraction of the observation group used minimally invasive method , the control group used traditional chisel .Then Compare the operation time , intr-aoperative and postoperative complications of the two groups .Result: The data showed that the changes in blood pressure and heart rate caused by stress in patients with minimally invasive extraction group were smal -ler than those of patients with traditional extraction method .In the observation group , the rate of the root frac-ture and the alveolar socket incomplete was lower , intraoperative or postoperative pain of the patients was smaller, the surgery time was shorter .Conclusion:The uncomfortable feeling in patients with minimally in-vasive extraction was significantly lesser than the patients with traditional method .This kind of tooth extrac-tion is superior to the traditional method and it is worthy to be recommended .%目的:探讨应用微创技术拔除下颌第一磨牙的优越性。方法:对要求拔除下颌第一磨牙的126个复杂病例,分别采用微创拔牙法(观察组)与传统劈凿法(对照组)两种方法拔牙,对手术时间、术中和术后并发症进行比较。结果:观察组因紧张而引起的血压、心律变化较小;术中断根率及拔牙窝不完整率观察组明显低于对照组;观察组患者术中痛苦的程度及发生率也不及对照组;术后疼痛肿胀反应对照组多于观察组;观察组拔牙时间缩短。结论:应用微创技术拔除下颌第一磨牙优于传统拔牙方法,值得推广。

  16. A Comparison of the Clinical Efficacy of Extraction of Impacted Mandibular Third Molars Using High-speed ;Air-turbine Drill and the Traditional Dental Method%两种方式拔除下颌第三磨牙阻生的对比研究

    Institute of Scientific and Technical Information of China (English)

    钟守鹏

    2016-01-01

    Objective To evaluate the feasibility and safety of using high-speed air-turbine drill to extract medium and low impacted mandibular third molars. Methods 369 cases were randomly divided into control group and experiment group. Tra-ditional hammer chisel splitting method was used in the control group and high-speed air-turbine drill in the experiment group. Lim-ited mouth opening, postoperative pain and dry sockets were observed. Results The duration of tooth extraction in the experiment group is significantly shorter than that in the control group(P<0. 05). The pain score and limited mouth opening between the two groups demonstrated significant difference(P<0. 05). Also postoperative complications such as dry sockets is obviously lower in the experiment group(P<0. 05). Conclusion The high-speed air-turbine drill shows obvious advantages in the extraction of low and medium impacted mandibular third molars with statistic significance.%目的:评价高速涡轮钻法拔除下颌中、低位阻生智齿的临床可行性及其优越性。方法作者对369颗下颌阻生智齿随机采用凿骨劈冠术(对照组)或高速涡轮钻法(实验组)去除阻力两种拔除方法,进行临床观察分析,记录患者张口受限程度、疼痛程度及干槽症的发病情况。结果实验组手术时间明显比对照组手术时间短,差异有统计学意义(P<0.05)。两组患者疼痛程度和张口受限程度的构成比差异有统计学意义(P<0.05)。两组干槽症的发病率差异有统计学意义(P<0.05),实验组发病率明显低于对照组。结论高速涡轮钻法能显著缩短手术时间,减轻患者术后的疼痛、张口受限、干槽症等不良反应,值得临床推荐。

  17. Effect of Conversion from Natural Grassland to Arable Land on Soil Carbon Reserve in the Argentinean Rolling Pampas

    Science.gov (United States)

    Andriulo, A. E.; Irizar, A. B.; Mary, B.; Wilson, M. G.

    2012-04-01

    The evaluation of the effect of land use change on accumulation of soil organic carbon (SOC) requires reliable data obtained from georeferenced sites with land use history records. The purpose of this study was to evaluate long term changes in the reserves of SOC in a typical Argiudol of the Pergamino series after the introduction of agriculture. Measures of soil organic carbon concentration and bulk density of Ap and A12 horizons were carried out in three sites of the Pergamino County (N of Buenos Aires province): a reference field with untilled pristine soil (33° 57' S; 60° 34' W), a field with 31 years (1980-2011) of agriculture (31Y) located next to the former, and a third field (33° 46' S; 60° 37' W) with 80 years (1910/1990) of agriculture (80Y). 31Y has been under continuous soybean cultivation with conventional tillage (CT) that consists of moldboard plow or double disk harrowing. At 80K the cultivation sequence was: 44 years of corn + 9 years of flax + 2 years of wheat + 17 years of wheat/soybean double cropping + 1 year of lentil; mostly under CT, some years under chisel plow during the 70's and a few years under zero tillage in soybean after wheat sown with conventional tillage during the 80's. Before the introduction of mechanical harvesting (1947) crop residues were burnt as well as the wheat stubble during the conventional double cropping period (1970-1980). Soil texture (23±1% clay, with predominance of illite) and field slopes (<0.5%) were similar in the three sites. Nitrogen and phosphorus fertilization rates were minimal due to the low crop response. The results are expressed in Mg ha-1 for an A soil horizon mass of 2500 Mg ha-1. The introduction of agriculture decreased SOC stock: 31Y varied from 68.3 to 40.1 Mg ha-1 (41.3% loss) and 80Y from 68.3 to 47.2 Mg ha-1 (30% loss). The SOC loss was the result of the mineralization of a large amount labile SOC present in the pristine soil and low annual additions of carbon issued from crop residue

  18. φq-field theory for portfolio optimization: “fat tails” and nonlinear correlations

    Science.gov (United States)

    Sornette, D.; Simonetti, P.; Andersen, J. V.

    2000-08-01

    Physics and finance are both fundamentally based on the theory of random walks (and their generalizations to higher dimensions) and on the collective behavior of large numbers of correlated variables. The archetype examplifying this situation in finance is the portfolio optimization problem in which one desires to diversify on a set of possibly dependent assets to optimize the return and minimize the risks. The standard mean-variance solution introduced by Markovitz and its subsequent developments is basically a mean-field Gaussian solution. It has severe limitations for practical applications due to the strongly non-Gaussian structure of distributions and the nonlinear dependence between assets. Here, we present in details a general analytical characterization of the distribution of returns for a portfolio constituted of assets whose returns are described by an arbitrary joint multivariate distribution. In this goal, we introduce a non-linear transformation that maps the returns onto Gaussian variables whose covariance matrix provides a new measure of dependence between the non-normal returns, generalizing the covariance matrix into a nonlinear covariance matrix. This nonlinear covariance matrix is chiseled to the specific fat tail structure of the underlying marginal distributions, thus ensuring stability and good conditioning. The portfolio distribution is then obtained as the solution of a mapping to a so-called φq field theory in particle physics, of which we offer an extensive treatment using Feynman diagrammatic techniques and large deviation theory, that we illustrate in details for multivariate Weibull distributions. The interaction (non-mean field) structure in this field theory is a direct consequence of the non-Gaussian nature of the distribution of asset price returns. We find that minimizing the portfolio variance (i.e. the relatively “small” risks) may often increase the large risks, as measured by higher normalized cumulants. Extensive

  19. Occupational and environmental mercury exposure among small-scale gold miners in the Talensi-Nabdam District of Ghana's Upper East region.

    Science.gov (United States)

    Paruchuri, Yasaswi; Siuniak, Amanda; Johnson, Nicole; Levin, Elena; Mitchell, Katherine; Goodrich, Jaclyn M; Renne, Elisha P; Basu, Niladri

    2010-11-15

    Mercury use in small-scale gold mining is ubiquitous across Ghana but little is known about the extent to which such activities have contaminated community residents and miners. Here, occupational exposures to elemental mercury (via urine sampling) and dietary exposures to methylmercury (via hair sampling) were assessed among 120 participants recruited from a mining community located in the Talensi-Nabdam District of Ghana's Upper East region during summer 2009. More than one-fifth of the participants had moderately high levels of urinary mercury (>10μg/L) and 5% had urine mercury levels that exceeded the WHO guideline value of 50μg/L. When participants were stratified according to occupation, those active in the mining industry had the highest mercury levels. Specifically, individuals that burned amalgam had urine mercury levels (median: 43.8μg/L; mean ± SD: 171.1±296.5μg/L; n=5) significantly higher than median values measured in mechanical operators (11.6μg/L, n=4), concession managers/owners (5.6μg/L, n=11), excavators that blast and chisel ore (4.9μg/L, n=33), individuals that sift and grind crushed ore (2.2μg/L, n=47), support workers (0.5μg/L, n=14), and those with no role in the mining sector (2.5μg/L, n=6). There was a significant positive Spearman correlation between fish consumption and hair mercury levels (r=0.30) but not with urine mercury (r=0.18) though further studies are needed to document which types of fish are consumed as well as portion sizes. Given that 200,000 people in Ghana are involved in the small-scale gold mining industry and that the numbers are expected to grow in Ghana and many other regions of the world, elucidating mercury exposure pathways in such communities is important to help shape policies and behaviors that may minimize health risks.

  20. Consumo de combustível de um trator em função do tipo de pneu, da lastragem e da velocidade de trabalho Fuel consumption of a tractor as a function of the tyre type, ballasting and forward speed

    Directory of Open Access Journals (Sweden)

    Afonso Lopes

    2003-08-01

    Full Text Available Com o presente trabalho, teve-se como objetivo comparar o consumo de combustível de um trator agrícola operando com pneus (radial, diagonal e de baixa pressão em duas condições de lastragem (com e sem água nos pneus e quatro velocidades de deslocamento. O experimento foi realizado na FCAV-UNESP, Jaboticabal, SP, em condição de preparo do solo com escarificador. Utilizou-se um trator 4x2 TDA, com potência de 89 kW (121 CV no motor. Os pneus foram do tipo R1, com as seguintes características: radial (dianteiros: 14.9 R 26; traseiros: 620/75 R 30 diagonal (dianteiros: 14.9-26, traseiros: 23.1-30 e BPAF (dianteiros: 500/60-26.5; traseiros: 700/55-34. O delineamento experimental foi o de blocos casualizados, em esquema fatorial 3x2x4, com 24 tratamentos e 3 repetições. Os resultados evidenciaram vantagens para o trator quando equipado com pneus radiais. A condição de lastragem com água nos pneus ofereceu menor consumo específico. Observou-se também que o aumento da velocidade de deslocamento reduziu o consumo específico.The objective of this study was to compare the consumption of fuel of the FWD agricultural tractor, equipped with three types of tyres (bias ply, radial and low pressure, with and without tyre water ballasting, operating in four forward speeds. The research was carried out at FCAV/UNESP, SP, Brazil, The soil was tilled using a chisel plow. A tractor with 89 kW (121 HP engine power equipped with FWD was used in the experiment, and the tyres used had the following characteristics: radial (front: 14.9R26 and rear: 620/75R30, bias ply (front: 14.9-26 and rear: 23.1-30 and low pressure (front: 500/60-26.5 and rear: 700/55-34. The experiment was conducted in a completely randomized block design (3x2x4, with a total of 24 treatments and three replications. The results evidenced advantages for the tractor equipped with radial tyres. The ballasting condition with water in the tyres showed lower specific consumption. It was

  1. Qualidade das operações de preparo de solo por controle estatístico de processo Quality of tillage operations by statistical process control

    Directory of Open Access Journals (Sweden)

    Marcos Milan

    2002-06-01

    Full Text Available A concorrência em escala mundial obriga as empresas a buscar maior eficiência administrativa e operacional. As técnicas de controle estatístico de processo (CEP são uma das ferramentas que permitem a melhoria da qualidade e produtividade nas empresas. Desenvolvido e largamente aplicado nas indústrias, o CEP tem grande potencial de utilização na agropecuária. Tendo em vista o desenvolvimento desse potencial, esse trabalho tem por objetivo avaliar os efeitos da utilização do controle de qualidade em operações agrícolas de preparo do solo para a cultura do milho utilizando-se como ferramenta de análise o CEP. A utilização do controle na operação de escarificação proporcionou redução da variabilidade de dados de profundidade de trabalho média em 38,4% e aumento de 45,0% dos dados desejados. Na gradagem, houve redução de 9,8% dos dados médios de tamanho de torrões, e um aumento de 75,0% de torrões aceitáveis.Agricultural enterprises must have a professional business management and competitive operational techniques to face competition. The statistical process control (SPC technique is one of the tools that improve quality and productivity of the companies. Developed and used in factories, the SPC has a large application potential for farming and stocking. Facing this potential development, the aim of this study was to evaluate the quality control effects on tillage operations using the SPC as an evaluation tool. The quality control for the chisel operation provided a reduction of 38.4% on data average variability and increased desired data to 45.0%. For the harrow operation, provided a reduction of 9.8% of the average diameter, and increased in 75.0% the desired stone diameter rate for the area.

  2. Nitrogen Fertilizer Rate and Crop Management Effects on Nitrate Leaching from an Agricultural Field in Central Pennsylvania

    Directory of Open Access Journals (Sweden)

    Richard H. Fox

    2001-01-01

    Full Text Available Eighteen pan lysimeters were installed at a depth of 1.2 m in a Hagerstown silt loam soil in a corn field in central Pennsylvania in 1988. In 1995, wick lysimeters were also installed at 1.2 m depth in the same access pits. Treatments have included N fertilizer rates, use of manure, crop rotation (continuous corn, corn-soybean, alfalfa-corn, and tillage (chisel plow-disk, no-till. The leachate data were used to evaluate a number of nitrate leaching models. Some of the highlights of the 11 years of results include the following: 1 growing corn without organic N inputs at the economic optimum N rate (EON resulted in NO3–-N concentrations of 15 to 20 mg l-1 in leachate; 2 use of manure or previous alfalfa crop as partial source of N also resulted in 15 to 20 mg l-1 of NO3–-N in leachate below corn at EON; 3 NO3–-N concentration in leachate below alfalfa was approximately 4 mg l-1; 4 NO3–-N concentration in leachate below soybeans following corn was influenced by fertilizer N rate applied to corn; 5 the mass of NO3–-N leached below corn at the EON rate averaged 90 kg N ha-1 (approx. 40% of fertilizer N applied at EON; 6 wick lysimeters collected approximately 100% of leachate vs. 40–50% collected by pan lysimeters. Coefficients of variation of the collected leachate volumes for both lysimeter types were similar; 7 tillage did not markedly affect nitrate leaching losses; 8 tested leaching models could accurately predict leachate volumes and could be calibrated to match nitrate leaching losses in calibration years, but only one model (SOILN accurately predicted nitrate leaching losses in the majority of validation treatment years. Apparent problems with tested models: there was difficulty estimating sizes of organic N pools and their transformation rates, and the models either did not include a macropore flow component or did not handle macropore flow well.

  3. Occupational and environmental mercury exposure among small-scale gold miners in the Talensi-Nabdam District of Ghana's Upper East region.

    Science.gov (United States)

    Paruchuri, Yasaswi; Siuniak, Amanda; Johnson, Nicole; Levin, Elena; Mitchell, Katherine; Goodrich, Jaclyn M; Renne, Elisha P; Basu, Niladri

    2010-11-15

    Mercury use in small-scale gold mining is ubiquitous across Ghana but little is known about the extent to which such activities have contaminated community residents and miners. Here, occupational exposures to elemental mercury (via urine sampling) and dietary exposures to methylmercury (via hair sampling) were assessed among 120 participants recruited from a mining community located in the Talensi-Nabdam District of Ghana's Upper East region during summer 2009. More than one-fifth of the participants had moderately high levels of urinary mercury (>10μg/L) and 5% had urine mercury levels that exceeded the WHO guideline value of 50μg/L. When participants were stratified according to occupation, those active in the mining industry had the highest mercury levels. Specifically, individuals that burned amalgam had urine mercury levels (median: 43.8μg/L; mean ± SD: 171.1±296.5μg/L; n=5) significantly higher than median values measured in mechanical operators (11.6μg/L, n=4), concession managers/owners (5.6μg/L, n=11), excavators that blast and chisel ore (4.9μg/L, n=33), individuals that sift and grind crushed ore (2.2μg/L, n=47), support workers (0.5μg/L, n=14), and those with no role in the mining sector (2.5μg/L, n=6). There was a significant positive Spearman correlation between fish consumption and hair mercury levels (r=0.30) but not with urine mercury (r=0.18) though further studies are needed to document which types of fish are consumed as well as portion sizes. Given that 200,000 people in Ghana are involved in the small-scale gold mining industry and that the numbers are expected to grow in Ghana and many other regions of the world, elucidating mercury exposure pathways in such communities is important to help shape policies and behaviors that may minimize health risks. PMID:20875913

  4. Effects of changes in land use on soil physical properties and soil organic carbon content in a wheat-corn-sunflower crop sequence, in a loam soil of Argentina.

    Science.gov (United States)

    Aparicio, V.; Costa, J. L.

    2012-04-01

    The Argentinean Humid Pampas extend over about 60 million hectares, 90% of which are agricultural lands. The Southeast of the Buenos Aires Province is part of the Humid Pampas, it covers over 1,206,162 hectares, the mean annual temperature is 13.3 °C and the climate is sub-humid. At the present only 6% of the lands are used for pasture. The main activities are agriculture and cattle production. The main crops are wheat, sunflower, corn and soybean. The tillage systems used in the area are: moldboard plow (MP), chisel plow (CP) and no-till (NT). Excessive soil cultivation under MP generates decreases in the levels of soil organic carbon (SOC). The magnitude of such decrease depends on the intensity of the tillage system, the tillage timeliness and the amount and quality of the residues. Adopting NT may reduce the effects of intensive agriculture, through the maintenance and accumulation of SOC. However, there are evidences that, under NT, the bulk density (ρb) in the superficial layers of the soil increases. The soil compaction causes degradation of the soil structure, reduces the soil water availability and reduces the soil hydraulic conductivity. With this scenario and the tendency to increase the surface under NT in the Southeast Humid Pampas, we evaluated the evolution of some soil physical properties and the SOC in a 10-year experiment with a wheat-corn-sunflower rotation. The experiment was carried out in four localities at farmerś fields under three different tillage systems: MP, CP and NT in a randomized complete block design, considering each locality as a block. Each plot had 50 m in width by 100 m length and the treatments were: NT, MP and CP. The results of this experiment have allowed us to verify that: i) the wheat-corn-sunflower crop sequence showed a tendency to reduce the values of bulk density (ρb) but NT increased ρb in the superficial soil layers; ii) the more intensive the tillage system, the higher the change in the mean weight diameter

  5. The study of the radiation protection of propolis to the radiation effects in mice

    International Nuclear Information System (INIS)

    The profit which radiation brought to the Homo sapiens is very big. But, radiation has even harmful parameter for the human besides one case. After effect on man to the radiation is thought about, the individual of which sensibility is the highest is a fetus. Therefore, even an effects to this fetus is grasped precisely, and protection criterion and resource are decided from the viewpoint of the protection of radiation as well. If it does so, a child and maturitas aren't so difficult as in the protection of radiation and the managerial side. It was examined about control group, propolis administration chisels for medical use group, 1.5 Gy independent exposure group and propolis pluse 1.5 Gy group in this study. It was examined about the protection of radiation of propolis which to malformation, fetal death, arrested development, and so on in the organogenesis (8 days post conception) being done when sensibility is the highest against the teratogenesis. Preimplantation death rate was compared with the control group and the sham control group, and statistical significant difference wasn't recognized by a 1.5 Gy radiation independent exposure group, propolis administration 1.5 Gy radiation exposure group. As for the embryonic death rate, propolis was administered, and obviously embryonic death rate was poorer than the 1.5 Gy independent exposure group, and significant difference was recognized by a 1.5 Gy radiation exposure group (p<0.001). It has a 1.5 Gy radiation exposure group made clear by this research fetal death rate propolis administer more only 1.5 Gy exposure fetal death rate development low (p<0.001). Fetal death rate wasn't recognized by propolis administration group (Sham control). As for the teratogenesis rate, propolis was administered, and the teratogenesis rate of the 1.5 Gy radiation exposure group was higher than the 1.5 Gy radiation independent exposure group. But, this is thought anamorphosis appear by propolis administration so long as there was

  6. Bioanalytical applications of affinity-based nanotube membranes for sensing and separations

    Science.gov (United States)

    Caicedo, Hector Mario

    2008-11-01

    Nanotechnology has played an important role in the development of research and technology during the last two decades. The contribution of nanotechnology in different fields, along with the versatility of the constructed nanoscale materials, have made nanotechnology one of the most suitable tools to develop particular nanostructures to realize a desired function and application. A nanostructure is simply an entity at the nanometer scale with one, two or three dimensional features. Since nanotechnology covers a broad range of nanoscale materials, to simplify nanotechnology, it can be classified into two categories based on how the nanostructures are prepared: top-down and bottom-up. In the top-down methods, the nanostructures are constructed by chiseling larger bulk materials into entities of smaller size. Conversely, in the bottom-up case, small units are grown or assembled into their desired size and shape. The nanoporous materials specifically have attracted a lot of attention because they can be used for the synthesis of a variety of functional nanostructures of great usefulness in technology. These porous nanostructures usually combine many of the advantages of the top-down and bottom-up methodologies such as flexibility, size controllability, and cost. The research presented in this work utilizes nanoporous membranes to develop porous nanostructured platforms with potential applications in sensing and separations. In particular, this work is centered in fundamental studies for bioanalytical applications of affinity-based nanotube membranes for sensing and separations. A bottom-up methodology like the template synthesis was used to produce silica nanotubes inside of the pores of alumina membrane. The functionalization of the inside walls of these silica nanotube membranes allowed control of the functional behavior and properties of the nanostructured membrane during membrane-based separations and sensing. The general scheme of the work presented here, is

  7. Demanda energética na subsolagem realizada antes e depois de diferentes sistemas de preparo periódico do solo Energy demand in the subsoiling performed before and after different systems of periodic soil tillage

    Directory of Open Access Journals (Sweden)

    Nilson Salvador

    2009-12-01

    Full Text Available A subsolagem é uma das operações mecanizadas de elevado custo e demanda energética por área, tradicionalmente utilizada pelos agricultores antes do preparo do solo na descompactação de camadas adensadas. Este trabalho teve como objetivo avaliar a demanda energética na operação de subsolagem realizada antes e depois de diferentes sistemas de preparo periódico num solo classificado como Nitossolo Vermelho Distroférrico. Os sistemas de preparo periódico foram: aração com discos; aração com discos mais uma gradagem de nivelamento; grade aradora; grade aradora mais gradagem de nivelamento e escarificação. O trator utilizado como fonte de potência no experimento foi um Valmet 128 (4x2tda. A demanda energética por área foi menor na subsolagem realizada depois do preparo periódico do solo, proporcionando uma economia de 21,9%. A realização da subsolagem depois do preparo periódico do solo resultou numa diminuição da exigência de força de tração em 21,1% e da potência disponível na barra de tração em 15%.Subsoiling is one of the mechanized operations of high cost and energy demand per area, traditionally utilized by farmers before soil tillage in the decompactation of hardened layers. This research was intended to evaluate the energy demand in the subsoiling operation performed before and after different systems of periodic tillage in a soil classified as Distroferric Red Nitossol. The periodic tillage systems were: plowing with disks; plowing with disks plus one leveling; plowing harrow; plowing harrow plus leveling and chiseling. The tractor utilized as a power source in the experiment was a Valmet 128 (4x2tda. The demand for energy area was lower in subsoiling held after the regular preparation of the soil, providing a saving of 21.9%. The completion of subsoiling after the preparation of the soil resulted in a decrease in demand for power to pull in 21% and 15% of the power available in the bar of traction.

  8. FY 2016 Status Report: CIRFT Testing Data Analyses and Updated Curvature Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Hong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-01

    This report provides a detailed description of FY15 test result corrections/analysis based on the FY16 Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT) test program methodology update used to evaluate the vibration integrity of spent nuclear fuel (SNF) under normal transportation conditions. The CIRFT consists of a U-frame testing setup and a real-time curvature measurement method. The three-component U-frame setup of the CIRFT has two rigid arms and linkages to a universal testing machine. The curvature of rod bending is obtained through a three-point deflection measurement method. Three linear variable differential transformers (LVDTs) are used and clamped to the side connecting plates of the U-frame to capture the deformation of the rod. The contact-based measurement, or three-LVDT-based curvature measurement system, on SNF rods has been proven to be quite reliable in CIRFT testing. However, how the LVDT head contacts the SNF rod may have a significant effect on the curvature measurement, depending on the magnitude and direction of rod curvature. It has been demonstrated that the contact/curvature issues can be corrected by using a correction on the sensor spacing. The sensor spacing defines the separation of the three LVDT probes and is a critical quantity in calculating the rod curvature once the deflections are obtained. The sensor spacing correction can be determined by using chisel-type probes. The method has been critically examined this year and has been shown to be difficult to implement in a hot cell environment and thus cannot be implemented effectively. A correction based on the proposed equivalent gauge-length has the required flexibility and accuracy and can be appropriately used as a correction factor. The correction method based on the equivalent gauge length has been successfully demonstrated in CIRFT data analysis for the dynamic tests conducted on Limerick (LMK) (17 tests), North Anna (NA) (6 tests), and Catawba mixed oxide (MOX) (10

  9. Efficiency of pneumatic and horizontal perforated disk meter mechanism in corn no-tillage seeders in soil with different mobilization reports Eficiência de dosadores pneumáticos e disco horizontal perfurado na semeadura direta de milho em solo com distintos históricos de mobilização

    Directory of Open Access Journals (Sweden)

    Denise Mahl

    2008-09-01

    Full Text Available This work objectified to evaluate the efficiency of two meter mechanism of corn seeds when submitted to different forward speed and soil management system during the non-tillage seeding. It was used a factorial design in randomized blocks. The factors whose effects were examined were related to the seeders with pneumatic and horizontal disk meter mechanisms for the distribution of the seeds, to the set tractor-seeder forward speeds (4.4; 8.0 and 9.8 km h-1, and to the soil management system considering the corn no-tillage seeding over minimum tillage with chisel plow and the no-tillage system for the seeding of oat culture (Avena strigosa Schreb. It was verified that the forward speed didn't influence the initial and final stands of plants but it interfered in the regularity of longitudinal distribution of plants. The smallest speed provided the largest percentile of normal spacing between plants. The pneumatic meter mechanism presented better performance than the horizontal disk perforated in the longitudinal distribution of plants. About corn productivity aspect it's indifferent the recommendation of use for pneumatic and perforated horizontal disk meter mechanism of seeds.Este trabalho teve o objetivo de avaliar a eficiência de dois mecanismos dosadores de sementes de milho quando submetidos à variação de velocidade de deslocamento e sistema de cultivo do solo, durante a operação de semeadura direta. O delineamento experimental foi em blocos casualizados, em arranjo fatorial com três fatores: dois mecanismos dosadores de semeadoras-adubadoras de precisão (pneumático e discos horizontais perfurados, três velocidades de deslocamento (4,4; 8,0 e 9,8 km h-1 e dois sistemas de cultivo (semeadura direta de milho sobre aveia-preta em solo preparado com escarificador e no sistema plantio direto. Verificou-se que a velocidade de deslocamento não influenciou nos estandes inicial e final de plantas, mas interferiu na regularidade de distribui

  10. ANALYSIS OF OPENERS OF SEEDERS IN RESOURCE SAVING TECHNOLOGIES OF GRAIN PLANTING

    Directory of Open Access Journals (Sweden)

    Priporov E. V.

    2015-05-01

    Full Text Available When sowing grain we apply resource saving technologies-technologies such as «no till» and a technology called «mini-till». «No till» involves planting crops on untreated surfaces. "Mini-till" is designed for the planting with minimum tillage. During the movement of the sowing unit on these agricultural backgrounds we can see working bodies tipping out. Stabilization of the drilling depth is ensured in two ways - by moving part of the weight of the planter on the opener or the installation of ballast weights. Openers of grain drills for resource saving technologies for grain crops can be divided into three groups – foot, disc and anchor. Disc coulter has varieties – single disc, double disc and montesquiu coulter. To analyze the cost of power for the operation of the opener, the following indicators – the minimum engine power of the tractor on the coulter and engine power of tractors per unit of working width. The calculation of the indicators was conducted using data the technical specifications of the planter. Snow coulter drill AGRATOR4800 provides a wide spread planting strip of 10-15cm. The minimum power of the engine of the tractor on the opener is 7.5 HP minimum power of tractor engine per unit of working width 25 HP/m. Double disc opener planter Great Plains has a minimum engine power of the tractor on the opener 2.7 HP and per unit of working width 26.0-28.44 HP/m. Planter equipped with disc knife for strip tillage. The planter Condor 1201 is provided with a chisel opener «ConTeC». The engine power of the tractor on the opener of the planter is 4.58 HP, the engine power of the tractor unit working width constitute l8.33 HP/m. This grain seeder has reduced power losses and provides sowing with a «no till» technology

  11. The study of the radiation protection of propolis to the radiation effects in mice

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Y.H.; Suzuki, Ikukatsu; Hasegawa, Takeo; Muto, H. [Suzuka Univ. of Medical Science, Mie (Japan); Yanagisawa, Takaharu; Iwasa, Toshihiro; Bamen, K.

    2000-05-01

    The profit which radiation brought to the Homo sapiens is very big. But, radiation has even harmful parameter for the human besides one case. After effect on man to the radiation is thought about, the individual of which sensibility is the highest is a fetus. Therefore, even an effects to this fetus is grasped precisely, and protection criterion and resource are decided from the viewpoint of the protection of radiation as well. If it does so, a child and maturitas aren't so difficult as in the protection of radiation and the managerial side. It was examined about control group, propolis administration chisels for medical use group, 1.5 Gy independent exposure group and propolis pluse 1.5 Gy group in this study. It was examined about the protection of radiation of propolis which to malformation, fetal death, arrested development, and so on in the organogenesis (8 days post conception) being done when sensibility is the highest against the teratogenesis. Preimplantation death rate was compared with the control group and the sham control group, and statistical significant difference wasn't recognized by a 1.5 Gy radiation independent exposure group, propolis administration 1.5 Gy radiation exposure group. As for the embryonic death rate, propolis was administered, and obviously embryonic death rate was poorer than the 1.5 Gy independent exposure group, and significant difference was recognized by a 1.5 Gy radiation exposure group (p<0.001). It has a 1.5 Gy radiation exposure group made clear by this research fetal death rate propolis administer more only 1.5 Gy exposure fetal death rate development low (p<0.001). Fetal death rate wasn't recognized by propolis administration group (Sham control). As for the teratogenesis rate, propolis was administered, and the teratogenesis rate of the 1.5 Gy radiation exposure group was higher than the 1.5 Gy radiation independent exposure group. But, this is thought anamorphosis appear by propolis administration so

  12. Efeito de três sistemas de preparo do solo sobre a rentabilidade econômica da mandioca (Manihot esculenta Crantz = Effects of three tillage systems on economic profitability of cassava crop (Manihot esculenta Crantz

    Directory of Open Access Journals (Sweden)

    Manoel Genildo Pequeno

    2007-07-01

    Full Text Available O objetivo deste estudo foi avaliar a rentabilidade econômica da cultura damandioca em três sistemas de preparo de solo durante os anos agrícolas de 1999/2000 a2002/2003, em Araruna, Estado do Paraná. O delineamento experimental utilizado foi o deblocos completos casualizados, com oito repetições. Os tratamentos foram constituídos deplantio direto; preparo mínimo (escarificação e preparo convencional (aração + gradagemniveladora. A força de tração e o consumo de combustível requeridos nas operações depreparo do solo e de plantio da mandioca foram maiores no sistema de preparoconvencional. Os maiores custos com combustível, preparo do solo e plantio da mandioca, ecusto operacional relativo às culturas de inverno e à cultura da mandioca, bem como a maiorrenda bruta foram observados no sistema de preparo convencional, seguidos pelo preparomínimo e plantio direto. A maior renda líquida e a melhor relação benefício/custo foramobservadas no sistema de preparo convencional que proporcionou maior produtividade deraízes tuberosas em relação aos sistemas de preparo mínimo e de plantio direto.The objective of this paper was to evaluate the economicprofitability of cassava crop submitted to the three soil tillage systems during the years1999/2000 to 2002/2003, in Araruna, state of Parana. The treatments consisted of three soiltillage systems: no-tillage, minimum tillage using chiseling, and conventional tillage withmoldboard plow and disking, arranged in a randomized complete blocks with eightreplications. The traction strength and fuel consumption in the soil tillage and in the cassavasowed operation were more required in the conventional tillage system. The conventionaland the minimum tillage systems showed the highest costs for fuel, soil tillage and cassavasowed. They also presented the highest gross income. The greatest net income and the bestbenefit/cost relation were observed in the conventional tillage system, which

  13. Correção da acidez do solo em função de modos de incorporação de calcário Correction of soil acidity in function of lime incorporation manners

    Directory of Open Access Journals (Sweden)

    Pedro Henrique Weirich Neto

    2000-04-01

    dystrophic Dark Red Latosol, in native field. A randomized complete block design was used, with three replications, in a split-plot experiment. The treatments consisted of five incorporation methods: disk plowing plus two spring disk harrowing, off-set harrowing plus two spring disk harrowing, rotary tilling, chisel plowing plus two spring disk harrowing and lime distribution on the surface without incorporation (main plots, and four rates of dolomitic limestone: 0, 2.8, 6.6 and 10.3 t ha-1, in order to raise base saturation of soil to 30, 60 and 90% (subplots. The cultivated plant was maize. The results showed that the lime incorporation manner in the soil affects its efficiency in relation to the depth in the profile in which there is neutralization of the acidity. There was elevation in base saturation of the soil to the layer of 20cm, 15cm and 10cm, respectively, for the following incorporation manners: rotary tilling, disk plowing or off-set harrowing and chisel plowing or lime distribution on the surface without incorporation. The saturation values for wanted bases were not reached, three months after liming, independent in the incorporation manner of lime.

  14. Research and Development of 2 BMYF-4 Intelligent No-till Maize Planter and its Field Experiment%2 BMFY-4型玉米免耕播种机研制与试验

    Institute of Scientific and Technical Information of China (English)

    杨自栋; 杜瑞成; 马明建; 蔡善儒; 刘宁宁

    2014-01-01

    Based on the agronomic characteristics with yearly maize-wheat rotation and large amount of straw cover after wheat harvesting and blocking during no-till maizeplanting in Shandong Province , a new-concept no-till wheat-maize planter , named 2 BMYF-4 intelligent no-till maize planter , has been researched and developed by researchers from Shandong University of Technology to solve some extremely important problems , such as chopping and covering standing wheat stubble in one-stop operation in double cropping areas of Shandong Province in China .The combined anti-bloc-king device composed of powered chopping axle and the planting unit with chisel opener was designed .The planting spacing regulation transmission was used to meet the needs of different planting densities .In order to meet the require-ments of automatic monitoring of farming quality and quantity of large scale precision seeders , an intelligent system with video monitor function for gauging and monitoring seed and fertilizer was researched and developed .Field performance test results at Zhangqiu , Zhangdian and Zhoucun showed that this planter could accomplish many procedures , such as stubble chopping , furrow opening , seed and fertilizer placement , suppressing , etc, in one-stop operation , thus the oper-ation cost could be reduced by about 30%.The machine worked very well for planting maize while shattering standing wheat stubble .The powered chopping axle resolved the anti-blockage problem ahead of shank , and the double-chisel o-pener unit reduced the blockage between planting units , thus the cross-country ability of the planter was improved . Meanwhile, the coefficients of variation(CV) for fertilizer and seed depth were reduced to 17.2%and 18.6%, respec-tively.The free-swinging knife of the planter can cut straw stubble in shallow soil with less than 20% soil breakage , which can prevent soil degradation .Therefore , this machine will be a good solution to no-till wheat-maize planting in

  15. Força de tração e volume de solo mobilizado por haste sulcadora em semeadura direta sobre campo nativo, em função do teor de água no solo, profundidade e velocidade de operação Draft and soil loosening by knife type coulter related to soil moisture and planter's working speed and depth

    Directory of Open Access Journals (Sweden)

    Carla T. C. Cepik

    2005-08-01

    Full Text Available A semeadura direta é um sistema de manejo eficiente em termos de conservação do solo e da água, economia de energia e capacidade operacional dos conjuntos mecanizados. No entanto, em áreas onde existem pecuária e produção de grãos, ou onde o solo é trafegado e trabalhado em condições inadequadas, pode ocorrer compactação do solo nas camadas superficiais. Mesmo compactadas, essas camadas não necessitariam ser descompactadas ou revolvidas, se boa germinação e desenvolvimento da cultura fossem alcançados apenas com a mobilização efetuada pelos sulcadores da semeadora. Os objetivos deste estudo foram determinar a força de tração demandada e o volume de solo mobilizado pelas hastes sulcadoras de adubo, além da patinagem do trator, em diferentes estados de consistência de um Argissolo, em semeadura direta sobre campo nativo dessecado. Houve aumento na demanda de tração com o aumento da profundidade de atuação da haste, e sua magnitude dependeu do estado de consistência do solo. O aumento da velocidade não influenciou na força de tração na haste em solos seco e úmido, porém, na condição de friabilidade, essa foi maior. O volume de solo mobilizado pelo sulcador foi maior em solo seco e a 12 cm de profundidade. Nos estados de consistência seco e friável e na maior profundidade testada, verificou-se a necessidade de acionamento da TDA do trator para obtenção de níveis aceitáveis de patinagem.Direct drilling or no tillage systems are among the most successful agricultural alternatives regarding soil and water conservation, energy economy and operational capacity of machinery. Some areas where cattle raising and grain production share the same grounds, or where soils are trafficked in moist conditions they may show compaction of the upper layers. Compacted soil areas may not need to be chiseled or plowed, if seed germination and good growing standards are reached by the initial soil conditioning solely by planter

  16. Consumo energético, eficiencia de campo y cobertura vegetal en labranza-siembra de maíz en el Valle del Cauca, Colombia

    Directory of Open Access Journals (Sweden)

    Herrera G Oscar A.

    2005-03-01

    Full Text Available En el Centro de Investigaciones Palmira de la Corporación Colombiana de Investigación Agropecuaria, Corpoica, se realizó un estudio de auditoría energética en cuatro métodos de labranza-siembra (vertisol de maíz en rotación con algodón. El mayor consumo de energía fósil correspondió a labranza convencional (LC, en la cual más del 70% se invirtió en las labores de labranza primaria y secundaria, seguida de cincel vibratorio (CV con un 65% y de mulch-tiller (MT con 54%; siembra directa (SD sólo empleó combustible fósil en la operación de desbroce de la soca y en la siembra; LC requirió casi 4 veces más energía que SD, CV casi 3 veces más y MT 2.7 veces más; el costo del combustible estuvo en igual proporción, lo mismo que el costo ambiental; en LC, MT y CV el primer pase del implemento de labranza consumió entre 1.5 y 3 veces más energía que el segundo y tercer pases, en suelos tenaces como los vertisoles del CI Palmira. Los altos valores de eficiencia de campo en LC contrastaron con el elevado consumo energético, en comparación con SD, y éste mostró diferencias notorias con respecto a los demás métodos de labranza-siembra en lo relacionado con la conservación de la cobertura vegetal del suelo. ABSTRACT Energy consumption, field efficiency and on ground vegetal cover in corn till-planting systems on Valle del Cauca, Colombia. Corn-cotton energy audit in four tillage-planting systems was carried out at the Colombian Corporation of Agricultural Research Center branch Palmira. The highest consumption of fossil energy corresponded to conventional tillage (LC, in which more than 70% of this consumption corresponded to primary and secondary tillage, followed by vibratory chisel (CV with 65% and mulch-tiller (MT with 54%, whereas no-till planting (SD observed the lowest energy consumption, because it suppressed itself primary and secondary tillage and only used fossil fuel to prepare the soca of the previous

  17. Morfologia de agregados do solo avaliada por meio de análise de imagens Morphology of soil aggregates evaluated by images analysis

    Directory of Open Access Journals (Sweden)

    N. Olszevski

    2004-10-01

    deterioration of soil physical properties, mainly due to modifications in the soil structure pattern. Once the structural changes could affect the morphology aggregates in different ways, the search for new methods of studying soil macro-morphological characteristics must be prioritized to allow the observation of modified characteristics in cultivated soils. Therefore, this study was carried out to adapt and test a digital method for a qualitative macro-morphological analysis of soil aggregates of Rodhic Haplustox in samples taken in 1998, aiming to detect morphological modifications caused by human activities. From an original set of eleven, five replicated treatments were selected: no till, cinzel plow, heavy disk harrow, disk plow and chisel plow, carried out annually. The shape of the different soil aggregates was from images obtained using a scanner (HP 6100C with 1200 dpi optical resolution which were then processed by the computer program UTHSCSA Image Tool. This program furnishes values of different aggregate indexes: roundness, compactness and lengthiness. The roundness index depends on the perimeter measurement (external roughness and the compactness and lengthiness indexes depend on the measurement of the length of the longest axle (long edges. Generally, the management systems used during three consecutive years did not modify the aggregate morphology of the clayey Rodhic Haplustox for the analyzed variables. Image analysis sensitively detected alterations in soil aggregate morphology promising considerable usefulness as a novel tool for on soil structure studies.

  18. THE CURATIVE EFFECT ANALYSIS OF EXTRACTION OF IMPACTED WISDOM TEETH BY MINIMALLY INVASIVE BONED BICUSPIDIZATION IN BASIC HOSPITAL%微创去骨分牙法拔除下颌阻生智齿在基层医院应用的疗效分析

    Institute of Scientific and Technical Information of China (English)

    史勇勇; 邓智明; 周仕宏; 张铁柱; 彭柏松

    2015-01-01

    Objective To study the curative effect analysis of extraction of impacted wisdom teeth by high speed turbine bodkin minimally invasive boned bicuspidization in basic hospital .Methods 164 outpatient service cases of Low ambush third molars were collected at The Red Cross Hospital of Lianzhou City from May 2013 to May 2015.All the cases were randomly divided into two groups , minimally invasivation group ( MI group) including 82 ca-ses and Conventional surgery group ( CS group ) including 82 cases.Minimally invasive boned bicuspidization was choosed in MI group , and traditional chisel was choosed in CS group .The duration of operations were recorded in all cases.Followed out-patient review at 1, 3, 7 day after operation.We compared the duration of operation , pain, limitation of mouth opening , swelling degree , and the incidence rates of alveolities and congestion and subcutaneous emphysema between two groups .Results The average duration of operation of MI group was less than CS group ( p0.05).The degree of mouth opening limitation of MI group is less than CS group at 1, 3, 7 day after operation.The incidence rates of alveolities congestion and subcutaneous emphyse-ma were no difference between two groups ( p>0.05 ) .Conclusion Extraction of impacted wisdom teeth by mini-mally invasive boned bicuspidization can shorten the duration of operation , and reduce the postoperative complica-tions, and can be applied in basic hospitals .%目的:探讨高速涡轮钻微创去骨分牙法拔除下颌阻生智齿在基层医院应用的疗效。方法收集连州市红十字会医院2013年5月~2015年5月门诊低位埋伏第三磨牙共164例,按随机数字法分为两组:微创组82例;常规组82例。微创组应用高速涡轮钻微创去骨分牙法,常规组应用凿骨劈冠法。所有手术病例均记录手术时间,并于术后第1、3、7天复查。对比分析两组患者手术时间,疼痛、张口受限、肿胀程度,淤血、皮下气

  19. Clinical application and evaluation of anterior interlocking plate internal fixation in ankle arthrodesis%前路锁定钢板内固定在踝关节融合术中的应用及初步评价

    Institute of Scientific and Technical Information of China (English)

    余剑; 赵建宁; 郭亭; 蔡滕

    2012-01-01

    目的 评价前路锁定钢板内固定在踝关节融合术中的临床应用及疗效.方法 收治各类踝关节终末期病变21例,踝前部皮肤、软组织条件均良好.采用踝关节前正中手术入路暴露踝关节前方,凿除踝关节软骨面,摆正踝关节体位,取肱骨近端或胫骨近端锁定钢板于踝关节前方行内固定.结果 所有患者随访6~47个月,X线片示踝关节全部融合.按AOFAS踝-后足功能评价系统,本组优15例,良6例.结论 前方入路锁定钢板内固定技术具有操作简单、暴露充分、避免额外截骨、固定牢靠等优点,融合率高,矫形力强,并发症少,能够较好恢复和维持躁关节的正常外形,尤其适合于合并畸形、关节周围骨缺损及骨质疏松等各类复杂踝关节终末期病变.%Objective To evaluate the the clinical application and efficacy of anterior approach plus internal fixation with interlocking plate in ankle arthrodesis. Methods From January 2007 to February 2011, twenty-one patients with end-stage disease of ankle joint were treated, and the skin and soft tissue conditions before the ankle were fine. All received operations including following steps: exposed the ankle with the anterior approach,chiseled to the ankle joint cartilage, straightened position of the ankle, made internal fixation with interlocking plate to ankle. Results All patients were followed up for 6 to 47 months, X-ray showed that full integration of ankle. According to the AOFAS assessment of ankle-foot functions, in this groups, 15 cases were excellent,6 cases were good. Conclusion The anterior approach plus internal fixation with interlocking plate in ankle arthrodesis have the advantages of simple operating, completely exposing, rigid fixing, avoiding osteotomy, which leads to high rate of fusion and correction and low rate of complication. In conclusion, this technique could correct deformity of ankle and maintain the stability excellently, and so it is

  20. Demanda energética e eficiência da distribuição de sementes de milho sob variação de velocidade e condição de solo Seeder energetic demand and distribution efficiency of corn seeds under speed variation and soil condition

    Directory of Open Access Journals (Sweden)

    Denise Mahl

    2004-04-01

    carried out under no tillage system during those last five years, soil prepared with chisel plow 18 months before seeding. Parameters of traction force, power, fuel consumption, effective field capacity, longitudinal distribution of plants, variation coefficient, precision index and initial plants stand were appraised. The results showed that increasing the speed of 4.4 to 8.1 km h-1, increases 86% the operational capacity of the group tractor/seeder, increasing 96% the power demand in the traction bar and reduction of 26% in the operational fuel consumption. The fastest speed (8.1 km h-1 provided a smaller percentile of normal spacing and an increasing in the percentile of multiple and fail spacing, larger variation coefficient and worse precision index. The speed variation didn't interfere in the plant stand.

  1. Temperatura do solo em função do preparo do solo e do manejo da cobertura de inverno Soil temperature as affected by soil tillage and management of winter cover crops

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Angeli Furlani

    2008-02-01

    Full Text Available Com o objetivo de avaliar o efeito do preparo do solo e do manejo da cobertura de inverno (consórcio aveia-preta + nabo forrageiro sobre a temperatura do solo, realizou-se um experimento em um Nitossolo em Botucatu-SP no outono/inverno de 2000. Utilizou-se um delineamento em blocos casualizados em esquema fatorial 3 x 3 (três preparos e três manejos. O preparo do solo constou de: preparo convencional, preparo conservacionista com escarificação e plantio direto, e o manejo da cobertura: consórcio dessecado, rolado e triturado. Foram avaliados a temperatura do solo (termopares a 5 cm de profundidade, de hora em hora, aos 7, 14, 30, 45 e 60 dias após a emergência das plantas do consórcio; o teor de água do solo na profundidade de 10 cm, nas mesmas épocas; e a cobertura do solo (massa seca e índice de cobertura, imediatamente após aplicação dos tratamentos. O sistema plantio direto apresentou temperaturas do solo menores que as do preparo convencional, até o 14º dia após emergência (DAE das plantas. A partir do 30° DAE das plantas, a temperatura não foi mais influenciada pelos tratamentos, devido à cobertura do consórcio e ocorrência de boa disponibilidade de água no solo. Os manejos da cobertura com rolo-faca, triturador e herbicida não influenciaram a temperatura do solo. A temperatura do solo não interferiu no crescimento e desenvolvimento das culturas de cobertura.To evaluate the effect of soil tillage and management of winter cover crops (black oat + radish intercrop on the soil temperature, an experiment was conducted in a Nitossol (Alfisol in Botucatu, state of São Paulo, Brazil, in the 2000 fall/winter season. A design in randomized blocks was used in a 3 x 3 factorial scheme (three tillage and three cover crop managements. Soil tillage consisted of: conventional tillage, conservation tillage with chiseling, and no-tillage. The cover crops managements included plant killing with post-emergence herbicide, rolling

  2. Parâmetros solo-máquina em função de doses de resíduos vegetais e profundidades de deposição de adubo em semeadura direta Parameters of soil-machine in function of the amount of cover residues and different fertilizer deposition depths in direct drilling

    Directory of Open Access Journals (Sweden)

    Karina M. Kamimura

    2009-09-01

    , sub-plots were two working depth of the driller chisel-type furrow opener, and two traffic conditions (combine and tractor wheel traffic.The physical characteristics of the soil were influenced by the traffic tracks. The whole tractor-drill was influenced by the depths of fertilizer shanks and traffic of traffic tracks and combine.

  3. U-series dating of pillow rim glass from recent volcanism at an Axial Volcanic Ridge

    Science.gov (United States)

    Thomas, L. E.; van Calsteren, P. W.; Jc024 Shipboard Party

    2010-12-01

    Visual observations using camera systems on the tethered ROV Isis deployed during the 2008 JC024 cruise to the Mid Atlantic Ridge at 45°N showed1 numerous monogenetic volcanoes that are essentially piles of lava pillows. The pillows are usually ˜1m diameter and >2m long and form mounds with average dimensions around 300m diameter, ˜150m altitude, and 0.005km3 volume. Small protrusions, 10-50cm long, which are numerous on pillows appear to be the youngest regions, were sampled using the pincers on the hydraulic arms of Isis, and returned to the surface. On the surface, any glass crust on the pillow protrusions was chiselled off using clean tools and double bagged in polythene. In the laboratory a portion of the glass was crushed in a jeweller’s roller mill and sieved using stainless steel sieves to obtain a sufficient amount of the fraction 0.125-0.250mm for hand picking, using a binocular microscope with the glass submerged in a mix of water and iso-propyl alcohol. The samples were subsequently leached using the procedure of Standish & Sims2. Samples were spiked with a mixed 229Th-236U spike and the U, Th and Ra fractions were separated and purified using standard chemistry methods. U and Th isotope ratios were determined using a Nu Instruments MC-ICPMS and Ra isotope ratios were determined using a MAT-262-RPQII TIMS instrument. The U-series data were evaluated using a MathCad program based on published4,5,6 equations. The data can be successfully modelled by assuming the ‘accepted’ mantle upwelling rate for the region of 11mm.y-1. The U-Th characteristics are mostly derived during ‘porous flow’ magma upwelling in the garnet stability zone, ranging to a depth of 60km with incipient melting starting at 70km. Above 60km depth the melt fraction will be >3% and the mantle mineralogy devoid of phases that fractionate U-Th significantly. Moreover, at melt fractions >3%, channel flow will be dominant and magma will transit to eruption on time-scales that are

  4. 中国家具木工工艺发展简史研究(下)%Research of the Brief History of Chinese Furniture Woodworking

    Institute of Scientific and Technical Information of China (English)

    胡景初

    2013-01-01

    本文通过对中国家具木工工艺发展的推进来叙述了:从新石器时期采用简单原始的石斧、石刀等工具对木材进行伐砍、裂解、表面加工及对构件的榫卯加工等基础的木材加工工艺,到古代木工工艺在铁器冶炼技术基础之上,由此产生手工框锯的发明与完善带来了木材剖解工艺的进展,由手推刨发明所带来木材表面加工工艺的进展,由刀凿、钻的发明带来榫卯接合工艺与雕刻工艺的进展,至近代时期,木材加工进入了半手工半机械的阶段,带动了木材专业的分工和家具厂的出现,胶合板的制造及其在家具产品中的应用极大促进了我国木材工业和家具制造业的发展,在进入现代化阶段后,以专用家具木工机械取代通用木工机械,以生产线的形式组织生产,以数控机床带动家具木工工艺的信息化,以柔性化生产开始了大规模定制等。综上所述,文章总结出各个时期中家具木工工艺的不同特点,同时也阐述了中国木工工艺发展的主线和内涵。%This article describes the study by the brief history of furniture woodworking. From use simple primitive axes and knives to cut, split and surface processing the wood in the Neolithic period to ancient woodworking base on smelting technology. It brings a development of wood anatomy process and a development of wood surface processing technology by hand plane invention and a development of mortise and tenon joint by knife chisel invent. Wood processing has into a stage of semi-manual semi-mechanical in modern period and has guides the division of the wood and the emergence of furniture factory. The Manufacture of plywood and the Application of the product in the furniture greatly promoted the development of timber industry and the furniture manufacturing in our country. After entering the modern stage, using special furniture woodworking machinery to replace the general

  5. 中国家具木工工艺发展简史研究(上)%Research of the Brief History of Chinese Furniture Woodworking

    Institute of Scientific and Technical Information of China (English)

    胡景初

    2013-01-01

    本文通过对中国家具木工工艺发展的推进来叙述了:从新石器时期采用简单原始的石斧、石刀等工具对木材进行伐砍、裂解、表面加工及对构件的榫卯加工等基础的木材加工工艺,到古代木工工艺在铁器冶炼技术基础之上,由此产生手工框锯的发明与完善带来了木材剖解工艺的进展,由手推刨发明所带来木材表面加工工艺的进展,由刀凿、钻的发明带来榫卯接合工艺与雕刻工艺的进展,至近代时期,木材加工进入了半手工半机械的阶段,带动了木材专业的分工和家具厂的出现,胶合板的制造及其在家具产品中的应用极大促进了我国木材工业和家具制造业的发展,在进入现代化阶段后,以专用家具木工机械取代通用木工机械,以生产线的形式组织生产,以数控机床带动家具木工工艺的信息化,以柔性化生产开始了大规模定制等。综上所述,文章总结出各个时期中家具木工工艺的不同特点,同时也阐述了中国木工工艺发展的主线和内涵。%This article describes the study by the brief history of furniture woodworking. From use simple primitive axes and knives to cut, split and surface processing the wood in the Neolithic period to ancient woodworking base on smelting technology. It brings a development of wood anatomy process and a development of wood surface processing technology by hand plane invention and a development of mortise and tenon joint by knife chisel invent. Wood processing has into a stage of semi-manual semi-mechanical in modern period and has guides the division of the wood and the emergence of furniture factory. The Manufacture of plywood and the Application of the product in the furniture greatly promoted the development of timber industry and the furniture manufacturing in our country. After entering the modern stage, using special furniture woodworking machinery to replace the general

  6. Perdas de solo, água e nitrogênio por erosão hídrica em diferentes sistemas de manejo Soil, water and nitrogen losses through erosion under different tillage systems

    Directory of Open Access Journals (Sweden)

    Jean Cláudio Guadagnin

    2005-04-01

    NH4+ and NO3- losses in water and mineral nitrogen in runoff sediment were determined under natural rainfall in the following tillage systems: six years of no-tillage (NT6, nine years of no-tillage (NT9, nine years of chisel plow plus disking cultivation (CD9, nine years of plowing plus double disking (PD9 and nine years of plowing plus double disking without crop planting (BS9. The experiment was conducted on an Inceptisol (Haplumbrept with a mean slope of 0.102 m m-1 from November 1999 to October 2001. In the treatments with soil cultivation a rotation of crops including bean, vetch, maize, and oat was used and, in crop succession, soybean, wheat, soybean, and wheat was adopted. Soil and water losses were higher in the conventional soil tillage than under soil conservation tillage systems. The NH4+ and NO3- concentrations in the runoff water from conventional soil tillage were lower than from soil conservation tillage, while the mineral nitrogen concentration in runoff sediment from the soil conservation was lower than from the conventional tillage treatments. Total NH4+ and NO3- losses through runoff water and nitrogen losses through the sediment were lower in the soil conservation than in the conventional soil tillage system.

  7. Observation of Application of High-speed Turbine Drills and Original Luxator Tooth Instruments in Impacted Wisdom Tooth Extraction Surgery%高速涡轮机、微创拔牙刀在阻生智齿拔除术中的应用观察

    Institute of Scientific and Technical Information of China (English)

    刘改英; 刘晓波; 张伟

    2015-01-01

    目的:观察在下颌中位近中水平阻生智齿拔除术中应用高速涡轮机、微创拔牙刀的优越性。方法选择因下颌中位近中水平阻生智齿导致下前牙牙列拥挤错位的年轻正畸患牙(者)80例,随机分成2组,研究组和对照组各40例。研究组拔牙器械采用高速涡轮牙钻和微创拔牙刀,对照组采用常规拔牙器械,记录术中牙齿拔除术所需时间、术中及术后7 d复诊时患者的症状。结果研究组平均拔牙时间15.1 min,对照组平均拔牙时间32.5 min,研究组平均拔牙时间明显少于对照组,术中、术后反应及满意度调查中研究组明显高于对照组。结论高速涡轮牙钻和微创拔牙刀在年轻患者下颌中位近中水平阻生智齿拔除术时具有明显优势。%Objective To shorten the tooth extraction time and reduce the postoperative complications, observe the advantage of ap⁃plication of high-speed turbine drills and original luxator tooth instruments in extraction of medial mesial horizontal impacted wisdom teeth of mandible. Method 80 cases of young orthodontic patients with the lower anterior teeth crowded dislocation caused by medial mesial horizontal impacted wisdom teeth of mandible are screened out during 3 years from March 2009 to March 2012, and randomly di⁃vided into two groups, study group and control group of 40 cases respectively. The study group adopts high-speed turbine drill and orig⁃inal luxator tooth instrument, while the control group adopts conventional extraction equipments (tooth forceps, chisel, hammer), then re⁃cord the extraction time, the patient's intraoperative and postoperative symptoms after seven days when referral. Results The average extraction time of the study group is 15 min, while the control group 32.5 min. The average extraction time of the study group is signifi⁃cantly less than that of the control group. As for intraoperative and postoperative reaction and patients

  8. Dacriocistorrinostomia endoscópica Endoscopic dacryocystrhinostomy

    Directory of Open Access Journals (Sweden)

    Bernardo Cunha Araujo Filho

    2005-12-01

    Full Text Available A dacricistorrinostomia (DCR endoscópica é uma técnica aceita e bem estabelecida no tratamento de obstruções distais da via lacrimal tornando seu domínio pelos otorrinolaringologistas indispensável. OBJETIVO: O objetivo desse artigo é apresentar a experiência em DCR endoscópica da Divisão de Clínica Otorrinolaringológica do Hospital das Clínicas da USP, comparando com os resultados na literatura. FORMA DE ESTUDO: clínico retrospectivo. MATERIAL E MÉTODO: Foram analisados prontuários de 17 pacientes (17 olhos, submetidos à DCR endoscópica, no período entre abril de 2001 e julho de 2004, na qual foram avaliados com relação a sexo, idade, etiologia, quadro clínico, técnica cirúrgica utilizada, uso de sonda de silicone e tempo de permanência, seguimento e as complicações observadas. RESULTADOS: Oito homens e nove mulheres, com idade variando de 29 a 79 (média: 42,64 13,1 apresentaram um seguimento médio de 15 meses. A causa principal da obstrução foi idiopática (58,8%. A epífora foi a queixa predominante. Em 6 pacientes utilizamos instrumentos motorizados, em um caso utilizamos o Laser Yag e no restante, chisel e martelo. Em todos os casos utilizamos sondas de silicone, por período médio de 7,9 semanas e o sucesso da técnica endonasal foi de 82,3%. CONCLUSÃO: A técnica endoscópica se mostrou uma técnica segura, com uma série de vantagens em relação à técnica externa e, desta forma, oftalmologistas e otorrinolaringologistas devem trabalhar em harmonia para oferecer maiores benefícios aos seus pacientes.Endonasal endoscopic dacryocystorhinostomy (EN-DCR is now a well-established procedure to relieve nasolacrimal duct obstruction, becoming its domain for the ENT surgeons indispensable. AIM: The aim of the present study is to report the experience of the Otorhinolaryngology Department of the University of São Paulo Medical School in the management of the obstruction of the drainage of the nasolacrimal

  9. 三种方法拔除近中中位水平阻生牙的效果比较%Comparison of three methods for extraction of near the median level of impacted tootheffect

    Institute of Scientific and Technical Information of China (English)

    毛全军

    2015-01-01

    Objective Analysis of advantages and disadvantages of 3 methods in the extraction of mandibular near the median level of impacted tooth. Methods 150 patients with 2013-2014 were se⁃lected in the mesial median level resistance,were randomly divided into 3 groups (n=50).A group us⁃ing the traditional split crown extractionmethod, and group B with three section extraction method,and group C with T-shape type of crown truncation method of extraction.Comparison of 3 methods of ex⁃tracting time, root cutting phenomenon appeared during the operation,swelling and pain, postopera⁃tive,sensitive patients with second molar surgery. Results 3 methods of extracting time,group C was the lowest,followed by group B, group A for the longest time,the difference was statistically signifi⁃cant (P0.05). Conclusion T-shape of crown truncation method of extraction and three section extraction method of clinical effect is better than that of traditional chisel in extraction methods.T-shape of crown trunca⁃tion method of extraction can shorten the operation time, worthy of clinical application.%目的:探讨3种方法在拔除下颌近中中位水平阻生牙的优缺点。方法:选取2013年1月-2014年3月我科收治的下颌近中中位水平阻生牙患者150例,随机均分为3组(n=50)。A组采用传统劈冠拔除方法,B组采用三段式横断拔除方法,C组采用“T”形截冠拔除方法。比较3种拔除方法所用时间,术中出现断根现象,术后疼痛、肿胀,第二磨牙术后出现敏感的患者。结果:3种拔除方法所用时间,C组最少,B组其次,A组时间最长,差异有统计学意义(P<0.05),B、C两组术中出现断根现象,术后疼痛、肿胀,第二磨牙术后出现敏感的发生率少于A组,差异有统计学意义(P<0.05),但是B、C两组间的数据差异没有统计学意义(P>0.05)。结论“:T”形截冠拔除方法和三段式横断拔除方法临床效果

  10. Characterization of Finnish Building materials under salt frost artificial ageing

    Science.gov (United States)

    Luodes, Nike M.; Torppa, Akseli; Pirinen, Heikki; Bellopede, Rossana; Marini, Paola

    2016-04-01

    Under a national project co financed by the Confederation of Finnish Construction Industries RT (CFCI), the Finnish Natural Stone Association and the Geological Survey of Finland (GTK), and thanks to the cooperation with the Polytechnic of Turin a comprehensive number of Finnish natural stones has been tested according to SFS EN standards for national CE marking and according to non standardized methods for research purposes. The aim was to evaluate the effects of combined salt and frost weathering caused by de-icing salts and to research a possible correlation between laboratory's accelerated decay and site weathering. The materials tested (60 stones in total) are mainly silicate rocks showing good resistance to the weathering. Results have been affected in some cases by uncertainties connected to the variation of material quality. Some materials have been from new quarries and variation of their properties has been higher than the effects of artificial weathering. Material sampled from crop presented higher weathering level and the additional artificial weathering has induced small variations. Results have shown that material weathering has been better represented by variation of flexural strength compared to uniaxial compressive strength. The most probable reason has been that small changes of planarity and perpendicularity had greater effects on the compressive strength than variations by weathering. Fifteen representative typologies of natural stones have been tested with non standardized methodologies to study the changes of the material and finding a possible correlation with methods used on site. Schmidt rebound test and Ultra Pulse Velocity (UPV) have been used on site to assess the durability of stone on construction. Materials tested in laboratory have shown less variation between rebounds compared to site tests, this can be because of a more controlled environment and saw cut surface instead of rocky or chiselled ones. Laboratory tests showed an average

  11. 高速涡轮机在下颌多根阻生智齿拔除术中的应用%Application of high-speed turbine in dental extraction with mandibular multiple resistance

    Institute of Scientific and Technical Information of China (English)

    杨益华; 王仁飞

    2014-01-01

    Objective To explore the application of high-speed turbine in dental extraction with mandibular multiple resistance in minimally invasive. Methods In the observation group,the no fear rate was 77.22%, which was significantly higher than that in the control group (21.52%) (P<0.05). The operation time in observation group was (14.87±3.13)min, which was significantly shorter than that in control group(P<0.05). The postoperative swelling, pain score, tooth nest integrity and limitation of mouth opening degree in observation group were significantly lower than that in control group (P<0.05). The postoperative satisfaction score in observation group was (8.89 ±1.61), which was significantly higher than that in control group(P<0.05). The total adverse reaction rate in observation group was 6.39%, which was significantly lower than 17.72% in the control group (P<0.05). Conclusion Comparing to the traditional instrument hammer and chisel, high speed turbine applied to extract mandibular impacted wisdom teeth had a plurality of short operation time, light postoperative pain, high satisfaction, less postoperative complications.%目的:探讨高速涡轮机在微创下颌多根阻生智齿拔除术中的应用。方法选择在本院实施下颌多根阻生智齿拔除的患者158例,根据拔除方式的不同分为对照组和观察组,每组均为79例。对照组常用采用传统拔牙器械锤凿去骨方式拔除,观察组采用高速涡轮机去骨方式拔除。比较两组手术时间、畏惧率、术后疼痛感、满意度、张口受限度、肿胀度、拔牙窝完整性和并发症等。结果观察组患者不畏惧率达到77.22%,显著高于对照组(P<0.05);观察组手术时间仅为(14.87±3.13)分钟,显著短于对照(P<0.05);术后肿胀度、痛度评分、拔牙窝完整性和张口受限度均显著低于对照组(P<0.05);术后观察组满意度评分达到(8.89±1.61),显著高于对照组(P<0.05);

  12. Técnica, Modernidade e Educação Formal Pública. Technique, modernity and public formal education

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    Silva, Cesar Augusto Alves da

    2009-05-01

    contemporary world. Since its beginning in the period to which may be called "modernity", this logic, the maximum efficiency in achieving the greatest gains in the shortest time possible, reached all the social relations in the contemporary world and is used in technology and science to achieve this goal. The configuration erected by the economic relations of capitalist production, in order to achieve its movement of reproduction, built an environment where the technique, transformed into a tool, object technology and form of action, shapes the behavior of human beings living in order to facilitate daily activities: reducing steps, creating patterns to perform them and reducing the need for complex thinking and prepared. Moreover, the acceleration of the pace of production from factories exceeded its walls and reached the lives of humans outside creating a climate of social and cultural high speed. Our goal is to demonstrate that this is a scenario which to make formal education uninteresting, as unnecessary, since the behavior is reckless required that the majority of human beings - especially the young. The conclusion we reached is that, for formal education, thought, reflection - and the slow pace to chisel both - is fundamental, but the actual human being has great potential to become totally averse to them.

  13. Overland flow connectivity in olive orchard plots with cover crops and conventional tillage, and under different rainfall scenarios

    Science.gov (United States)

    López-Vicente, Manuel; García-Ruiz, Roberto; Guzmán, Gema; Vicente-Vicente, José Luis; Gómez, José Alfonso

    2016-04-01

    The study of overland flow connectivity (QC) allows understanding the redistribution dynamics of runoff and soil components as an emergent property of the spatio-temporal interactions of hydrological and geomorphic processes. However, very few studies have dealt with runoff connectivity in olive orchards. In this study we simulated QC in four olive orchard plots, located on the Santa Marta farm (37° 20' 33.6" N, 6° 13' 44" W), in Seville province (Andalusia) in SW Spain. The olive plantation was established in 1985 with trees planted at 8 m x 6 m. Each bounded plot is 8 m wide (between 2 tree lines) and 60 m long (total area of 480 m2), laid out with the longest dimension parallel to the maximum slope and to the tree lines. The slope is uniform, with an average steepness of 11%. Two plots (P2 and P4) were devoted to conventional tillage (CT) consisting of regular chisel plow passes depending on weed growth. Another set of two plots had two types of cover crops (CC) in the inter tree rows (the area outside the vertical olive canopy projection): uniform CC of Lolium multiflorum (P3) and a mixture of L. rigidum and L. multiflorum together with other species (P5). The tree rows were treated with herbicide to keep bare soil. We selected the Index of runoff and sediment Connectivity (IC) of Borselli et al. (2008) to simulate three rainfall scenarios: i) low rainfall intensity (Sc-LowInt) and using the MD flow accumulation algorithm; ii) moderate rainfall intensity (Sc-ModInt) and using MD8; and iii) high rainfall intensity (Sc-HighInt) and using D8. After analysing the values of rainfall intensity during two hydrological years (Oct'09-Sep'10 and Oct'10-Sep'11) we associated the three scenarios with the followings months: Sc-LowInt during the period Jan-Mar, that summarizes 42% of all annual rainfall events; Sc-ModInt during Oct-Nov and Apr-May (32% of all events); and Sc-HighInt during the period Jun-Sep and in December (26% of all events). Instead of using the C

  14. Land use and land management effects on soil organic carbon stock in Mediterranean agricultural areas (Southern Spain)

    Science.gov (United States)

    Parras-Alcántara, Luis; Lozano-García, Beatriz

    2014-05-01

    INTRODUCTION Soils play a key role in the carbon geochemical cycle. Agriculture contributes to carbon sequestration through photosynthesis and the incorporation of carbon into carbohydrates. Soil management is one of the best tools for climate change mitigation. Small increases or decreases in soil carbon content due to changes in land use or management practices, may result in a significant net exchange of carbon between the soil carbon pool and the atmosphere. In the last decades arable crops (AC) have been transformed into olive grove cultivations (OG) or vineyards (V) in Mediterranean areas. A field study was conducted to determine long-term effects of land use change (LUC) (AC by OG and V) on soil organic carbon (SOC), total nitrogen (TN), C:N ratio and their stratification in Calcic-Chromic Luvisols (LVcc/cr) in Mediterranean conditions. MATERIAL AND METHODS An unirrigated farm in Montilla-Moriles (Córdoba, Spain) cultivated under conventional tillage (animal power with lightweight reversible plows and non-mineral fertilization or pesticides) was selected for study in 1965. In 1966, the farm was divided into three plots with three different uses (AC, OG and V). The preliminary analyses were realized in 1965 for AC (AC1), and the second analyses were realized in 2011 for AC (AC2 - winter crop rotation with annual wheat and barley, receiving mineral fertilization or pesticides), OG (annual passes with disk harrow and cultivator in the spring, followed by a tine harrow in the summer receiving mineral fertilization and weed control with residual herbicides), and V (with three or five chisel passes a year from early spring to early autumn with mineral fertilization or pesticides.). In all cases (AC1, AC2, OG and V) were collected soil entire profiles. Soil properties determined were: soil particle size, bulk density, SOC, TN, C:N ratio, stocks and SRs. The statistical significance of the differences in the variables between land use practices was tested using the

  15. Gneisses (Serizzi and Beole) of the Verbano-Cusio-Ossola district (Piedmont, Northern Italy): possible candidates for the designation of "Global Heritage Stone province"

    Science.gov (United States)

    Antonella Dino, Giovanna; Borghi, Alessandro; Cavallo, Alessandro; Primavori, Piero

    2016-04-01

    The Verbano-Cusio-Ossola quarrying district (Piedmont, northern Italy) produces many different ornamental stones (granites, gneisses, marbles): two really important categories are represented by Serizzo and Beola gneisses. Several varieties of Serizzo and Beola crop out in the upper and middle Ossola Valley: Serizzo derives from the Antigorio, Monte Leone and Monte Rosa Penninic Units, whereas Beola from the Monte Leone, Orselina-Moncucco-Isorno and Monte Rosa Penninic Units, as well from the Fobello-Rimella schists (Austroalpine). The Serizzo, represented by a group of foliated granitoid orthogneisses (Serizzo Antigorio, Serizzo Formazza, Serizzo Sempione and Serizzo Monte Rosa varieties), is probably the most important and extensively exploited ornamental stones from the VCO province (about 70% of the VCO stone production). The quarries are mostly concentrated in the Antigorio and Formazza valleys, where the Antigorio nappe has a sub-horizontal attitude and reaches its greatest thickness (up to 1000 m). This stone was largely used to produce columns since the end of XV century (e.g. the old Ospedale Maggiore in Milano, now University of Milano) and later on it was replaced with granites. It was also used in the building structure of the Duomo di Milano, for the plinth and the piers. Nowadays, thanks to its good wear resistance and low cost, it is mainly used in polished slabs for paving: a recent application is the Frankfurt airport floor. Beola is the name of a group of heterogeneous orthogneisses with mylonitic foliation and strong mineralogical lineation (Beola Grigia, Bianca, Ghiandonata, Striata varieties), easy to split into thin slabs with hammer and chisel, occurring in the middle Ossola Valley, between Vogogna and Montecrestese. The quarries of Beola are probably the oldest of the Ossola Valley, although the precise period in which the stone started to be exported is unknown. The Beola trade probably started at the end of the XIII century, with the

  16. NÍVEL DE POTÊNCIA SONORA NAS OPERAÇÕES AGRÍCOLAS

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    CORTEZ, Jorge Wilson

    2011-05-01

    Full Text Available The noise generated by agricultural mechanization brought side effects, and one of them is thedamage the hearing of the operator of agricultural machinery. The NR-15 establishes the limits of tolerance forcontinuous noise, and exposure to the maximum allowable noise level of 115 dB (A for individuals who are notusing individual protection equipment and 85 dB (A, considering a shift work of 8 h. The objective was to studythe influence of working speed and soil condition in agricultural operations in the determination of sound powerlevels emitted by the tractor. The study was conducted at the Center for Agricultural Sciences - UNIVASF,Petrolina / PE using a Valtra tractor model 785 TDA cabin and meter without the sound power level. Weevaluate the sound power level of the tractor in five speeds (3.0, 5.0, 8.7, 10.7 and 13.0 km h-1 on prepared soiland ground covered with weeds, with the equipment: lightweight tandem grid, grid light off-set with discs of55.8 cm, grade mild off-set with discs of 60.8 cm, chisel plow, mower and distributor commuting. The mostsignificant amounts were found in the tractor and plow in operation, noting that the requirement of increasedpower in the engine sound power level.O ruído gerado pela mecanização agrícola trouxe efeitos colaterais, e um deles é o dano à audiçãodo operador de máquinas agrícolas. A NR-15 estabelece os limites de tolerância para os ruídos contínuos, sendoa exposição máxima permitida ao nível de ruído de 115 dB (A para indivíduos que não estejam utilizandoequipamentos de proteção individuais e 85 dB (A, considerando uma jornada de trabalho de 8 h. O objetivodeste trabalho foi estudar a influência da velocidade de trabalho e a condição do solo nas operações agrícolas nadeterminação dos níveis de potência sonora emitido pelo trator. O trabalho foi realizado no Centro de CiênciasAgrárias da UNIVASF, Petrolina/PE utilizando um trator Valtra modelo 785 TDA sem cabine e o

  17. Evolution of physical properties of soils according to tillage systems on annual crops/ Evolução de propriedades físicas do solo em função dos sistemas de manejo em culturas anuais

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    Rogério R. M. Ferreira

    2006-06-01

    Full Text Available Soil management must keep the soil physical properties next to the original conditions in natural systems to assure the sustainability of agricultural systems. This review synthesizes the effects of conventional tillage, minimum tillage and no-tillage systems of annual crops, on soil physical properties as bulk density, porosity, soil resistance to root penetration, infiltration speed, hydraulic conductivity,compressibility, organic matter level, soil aggregate size and stability. No-tillage presents advantages on organic matter level, size and stability of aggregates, compressibility and hydraulic conductivity but has limitations on bulk density and resistance to root penetration. Minimum tillage with chisel plow is specially efficient in relation to infiltration speed and hydraulic conductivity, and intermediate between conventional and no-tillage in other aspects. Conventional tillage with total pulverization of soil surface,mainly on tropical conditions, presents the less favorable scores on soil physical properties, close to minimum tillage and no-till only in few circumstances, and frequently the most different from the natural conditions. The conservation systems by their side, despite of similarities in some aspects with natural conditions, are not able to reproduce the conditions of natural forests, savannas or natural pastures, but are in the sustainability direction.Para assegurar a sustentabilidade do sistema produtivo, o manejo do solo deve manter as propriedades físicas do solo o mais próximo das condições originais em que este se encontrava na natureza. Esta revisão sintetiza os efeitos de três sistemas de manejo de solo (convencional, mínimo e direto em culturas anuais sobre as propriedades físicas do solo como densidade, porosidade, resistência à penetração, velocidade de infiltração, condutividade hidráulica, compressibilidade, nível de matéria orgânica, tamanho e estabilidade de agregados. O plantio direto

  18. Status of bacterial colonization in infected root canal%感染根管内细菌定植状态的观察

    Institute of Scientific and Technical Information of China (English)

    郭惠杰; 岳林; 高岩

    2011-01-01

    目的:了解慢性根尖周炎患牙根管内的细菌感染状态,以指导临床治疗和评估预后.方珐:采用组织学与扫描电镜相结合的方法对临床不能保留的7例慢性根尖周炎患根进行超微结构观察,将新鲜拔除的患根沿牙长轴近、远、中向劈为两半,一半做组织学切片,采用Brown&Brenn染色观察,另一半做扫描电镜观察.结果:组织学切片细菌特染显示,大量细菌附着于根管壁表面并定植于根管壁牙本质小管深部,用测微尺测量细菌侵入深度为140~1000μm,根尖1/3段感染较重.扫描电镜结果显示,根管壁表面可见到致密、半封闭状态的网状细菌膜结构,大量球菌、杆菌和/或丝状菌镶嵌于无定形的基质中,集中于根尖1/3段.结论:慢性根尖周炎的根管内细菌以生物膜形式定植在根尖1/3区,并侵入牙本质小管深部,形成感染难以清除的区域.%Objective : To investigate the morphology, distribution and relative position of the bacteria in infected root canals with chronic apical periodontitis and make some clinical inferences. Methods: Seven extracted roots with chronic apical periodontitis were collected. Immediately after extraction, all specimens were rinsed in sterile saline solution. The remaining tooth crowns were cut off with carborundum disks under water spray. Longitudinal grooves following the root length axis were cut along the entire root by using tapered diamond burs under water spray, and the roots were then split with a chisel into two halves. One half of the roots were decalcified, and after dehydration and embedding in paraffin, serial sections of 4 μm were cut, parallel to the long axis of the roots. The sections were stained using the Brown & Brenn methods, which were examined with a light-transmitting microscope for the distribution of bacteria in the root canals. The other half of the roots were dehydrated, sputtered coated with gold, and then examined for the occurrence of

  19. Physical characterization of soil and operational performance of agricultural machines in the deployment of forage sorghumCaracterização física do solo e desempenho operacional de máquinas agrícolas na implantação da cultura do sorgo forrageiro

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    José Guilherme Lança Rodrigues

    2011-12-01

    Full Text Available Forage sorghum can be grown in areas presenting dry and hot environmental situations where the yield of other grasses can often be uneconomical. The objective of this study was to analyze the operating performance of agricultural machines in the deployment of sorghum forage in four tillage systems, as follows: no-tillage system, disk harrow + seeding, disk harrow + two light disking + seeding, minimum tillage + seeding and four seeding different speeds, as follows: 3, 5, 6 and 9 km h-1. The study was performed under field conditions in FCA / UNESP, Botucatu County, SP, Brazil. The data were subjected to variance analysis in a simple factorial 4 x 4, and a random block design with split plots. Operational performance of the agricultural machinery, physical characteristics the soil, its water content and the yield of dry matter and green sorghum were determined. The operational performance of agricultural machines in the deployment of sorghum forage is influenced by the sowing speed and the soil tillage system used. Chisel plow was the equipment that required the highest mean traction force, mean traction and slip, as well as the lowest mean speed for the studied tillage system. Forage sorghum showed higher yields in no-tillage systems at a seeding speed of 5 km h-1.O sorgo forrageiro pode ser cultivado em áreas e situações ambientais secas e quentes, onde a produtividade de outras forrageiras pode ser normalmente antieconômica. O objetivo do trabalho foi analisar o desempenho operacional de máquinas agrícolas na implantação da cultura do sorgo forrageiro em quatro sistemas de preparo do solo: semeadura direta; gradagem pesada + semeadura; gradagem pesada + duas gradagens leves + semeadura; cultivo reduzido + semeadura e quatro velocidades de semeadura: 3, 5, 6 e 9 km h-1. O experimento foi instalado em condições de campo, na FCA/UNESP, Campus de Botucatu - SP. Os dados obtidos foram submetidos à análise de variância em esquema

  20. Sucessão de culturas e sua influência nas propriedades físicas do solo e na produtividade do feijoeiro de inverno irrigado, em diferentes sistemas de manejo do solo Crop succession and its influence on soil physical properties and irrigated winter common bean yield, under different soil tillage systems

    Directory of Open Access Journals (Sweden)

    Matheus Gustavo da Silva

    2008-01-01

    shoot dry matter production, soil covering percentage, and the influence of crop rotation and tillage system on soil physical properties of a Rhodic Hapludox and to evaluate irrigated winter common bean yield. The experimental design was a randomized block, arranged in a split plot scheme, with four replications. The plots consisted of soil tillage system (heavy harrow, chisel plow and no-tillage and the subplots of six crop rotations sown in the summer (corn, corn + black velvet bean, corn + brachiaria grass, soybean, rice and sunhemp. The crop rotations that presented larger soil coverage and shoot dry matter production were sunnhep, corn + black velvet bean, corn + braquiaria grass and corn. No-tillage resulted in larger values of penetration resistance at 0.00 - 0.10 m layer. Except macro porosity at 0-0,1 m layer, the properties humidity, macroporosity, microporosity and total porosity of soil are not influenced by soil tillage systems. Despite differences in some yield components of common bean due to certain soil tillage or crop succession, the irrigated winter common bean crop yield was not affected.

  1. Corsica and Sardinia

    Science.gov (United States)

    2002-01-01

    Rich in antiquities and picturesque landscapes, the island provinces of Corsica, France, (top) and Sardinia, Italy, (bottom) have captured the imaginations of historians and poets alike for centuries. Corsica, crowned with snow-capped mountains, jeweled with shimmering lakes, and cloaked in misty emerald forests, is situated in the sapphire blue Mediterranean Sea southeast of mainland France. The island enjoys a relatively warm climate consisting of hot, dry summers full of sunshine, and mild winters that rarely dip below 0oC (32oF). In this scene, Corsica is the smaller island to the north. The island has almost 1,700 hills and mountains, ranging from 300 to over 2,700 meters in height. The tallest of these peaks is the snow-capped Monte Cinto toward the northern end of the island. Coursing throughout the island is an extensive network of rivers, carved into Corsica's granite face by snowmelt and rainwater runoff. The Corsican Cape sits on the island's northern finger; its eastern slope is somewhat hilly. There are quite a few agricultural fields and vineyards visible as the light green swath to the south all along the eastern shore. Along the southern shore are the dazzling cliffs of Bonifacio. Moving up the west coast in the state of Ajaccio we see a jagged, chiseled water front, reminiscent of the famous fjords of Norway. There are four large gulfs and many smaller rocky inlets sculpted into Corsica's west coast. Moving soutward, they are the Gulfs of Porto, Sagone, Ajaccio, and Valinco. The larger island to the south--across the Strait of Bonifacio--is Sardinia, Italy, one the earliest populated lands of Europe. Some ancient artifacts date human populations there as old as 6000 B.C. Around 1500 B.C., another group of settlers arrived on the island (historians don't know where they came from) and spread quickly across the island. Known as the Nuragic people, these settlers built almost 30,000 circular fortresses--called 'nuraghe'-- around the island; each

  2. DEMANDA ENERGÉTICA DA SEMEADURA DO MILHO EM DIFERENTES MANEJOS DO SOLO E ESPAÇAMENTOS ENTRE LINHAS

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    Erick Vinicius Bertolini

    2012-12-01

    Full Text Available The different soil surface conditions associated with each tillage system can change the sowing energy demand due to the complexity of their interactions with the tractor/seeder. Therefore, the objective of this work was to evaluate the effect of two soil tillage systems and two row spacings on energy demand of the corn sowing. The experiment was carried out at the “Faculdade de Ciências Agronômicas” (FCA of the “Universidade Estadual Paulista” (UNESP, Botucatu-SP campus, in a Dystric Nitosol. The experimental design was in randomized blocks with split-plots and four repetitions. The main plots consisted of two soil tillage systems (no-tillage and reduced tillage - chisel plow and the split-plots of row spacings (0.90 m and 0.45 m. Obtained results were analyzed by Tukey test at 5 % of probability for comparing averages. Statistical analysis showed that corn sowing in no-tillage system requires lower traction force, bar power demand, area energy specific consumption, hourly and area fuel consumption. Corn sowing in 0.45 m row spacing demands higher traction force, bar power demand, area energy specific consumption and hourly fuel consumptionAs diferentes condições da superfície do solo inerente a cada sistema de manejo podem afetar a demanda energética da operação de semeadura devido à complexidade de suas interações com o conjunto trator/semeadora. Assim sendo, o objetivo deste trabalho foi avaliar o efeito de dois sistemas de manejo do solo e dois espaçamentos entre linhas na demanda energética da operação de semeadura da cultura do milho. O experimento foi conduzido na Faculdade de Ciências Agronômicas (FCA da Universidade Estadual Paulista (UNESP, campus de Botucatu-SP, em Nitossolo Vermelho Distroférrico. O delineamento experimental utilizado foi de blocos ao acaso com parcelas subdivididas e quatro repetições. As parcelas foram constituídas pelos sistemas de manejo do solo (plantio direto e preparo reduzido

  3. Efeito da profundidade de trabalho das hastes sulcadoras de uma semeadora-adubadora na patinagem, na força de tração e no consumo de combustível de um trator agrícola Effects of work operation depth of shanks in a seeder-fertilizer on slip, traction force and fuel consumption of a tractor

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    Marcos Antonio Zambillo Palma

    2010-10-01

    Full Text Available A consolidação do sistema de semeadura direta trás grandes benefícios ao meio ambiente e, também, é notável a redução dos custos de produção devido a desnecessidade das operações como aração, subsolagem, escarificação e gradagem. Porém, nesse sistema se têm muitos problemas relacionados a compactação das camadas superficiais em função do tráfego de máquinas e a consorciação lavoura-pecuária. A solução encontrada pelos agricultores tem sido a substituição, na semeadora-adubadora, do sulcador disco duplo pela haste sulcadora que atua em profundidades superiores. O presente estudo teve como objetivo avaliar diferentes profundidades de trabalho da haste sulcadora, analisando o consumo de combustível, força de tração, índice de patinagem, potência na barra de tração, consumo específico de combustível e capacidade de campo teórica de um trator agrícola tracionando uma semeadora-adubadora em solo compactado pela integração lavoura-pecuária. Os tratamentos foram 100, 150, 200 e 250 mm de profundidade de trabalho da haste sulcadora, sendo os ensaios desenvolvidos no Departamento de Engenharia da Universidade Federal de Lavras, utilizando delineamento experimental de blocos, casualisados, composto por quatro tratamentos e três repetições. Dessa forma, conclui-se que o aumento da profundidade de trabalho da haste sulcadora em semeadoras-adubadoras de semeadura direta de milho em solos compactados ocorre o aumento no consumo de combustível, no índice de patinagem e no esforço de tração dos tratores agrícolas. Porém, quando a ponteira da haste sulcadora trabalhou posicionada 50 mm abaixo da camada mais compactada se teve reduções nos parâmetros força de tração e índice de patinagem, aumentando a capacidade de campo teórica.The direct sowing system brings many benefits to the environment and also reduction in production costs, since operations such as plowing, subsoiling, chiseling and harrowing

  4. Assessing Tillage Effects on Soil Hydraulic Properties via Inverse Parameter Estimation using Tension Infiltrometry

    Science.gov (United States)

    Schwen, Andreas; Bodner, Gernot; Loiskandl, Willibald

    2010-05-01

    Hydraulic properties are key factors controlling water and solute movement in soils. While several recent studies have focused on the assessment of the spatial variability of hydraulic properties, the temporal dynamics are commonly not taken into account, primarily because its measurement is costly and time-consuming. However, there is extensive empirical evidence that these properties are subject to temporal changes, particularly in the near-saturated range where soil structure strongly influences water flow. One main source of temporal variability is soil tillage. It can improve macroporosity by loosening the soil and thereby changing the pore-size distribution. Since these modifications are quite unstable over time, the pore space partially collapses after tillage. This effect should be largest for conventional tillage (CT), where the soil is ploughed after harvest every year. Assessing the effect of different tillage treatments on the temporal variability of hydraulic properties requires adequate measurement techniques. Tension infiltrometry has become a popular and convenient method providing not only the hydraulic conductivity function but also the soil rentention properties. The inverse estimation of parameters from infiltration measurements remains challenging, despite some progress since the first approach of Šimůnek et al. (1998). Measured data like the cumulative infiltration, the initial and final volumetric water content, as well as independently measured retention data from soil core analysis with laboratory methods, have to be considered to find an optimum solution describing the soil's pore space. In the present study we analysed tension infiltration measurements obtained several times between August 2008 and December 2009 on an arable field in the Moravian Basin, Lower Austria. The tillage treatments were conventional tillage including ploughing (CT), reduced tillage with chisel only (RT), and no-tillage treatment using a direct seeding

  5. Biodiversity impact of the aeolian periglacial geomorphologic evolution of the Fontainebleau Massif (France)

    Science.gov (United States)

    Thiry, M.; Liron, M. N.

    2009-04-01

    erosion of the sand beneath the bordering sandstone benches, resulting in overhangs. These structures are the most common in the western district of the Fontainebleau Massif. Ponds develop on the tightly silicified and impermeable sandstone pans that form the "platières". There are permanent ponds and temporary wet zones, formed of interconnected or isolated depressions. The origin of these ponds has to be questioned with regard to the landscape shaping. Their origin is directly bound to the hollowing of uncemented, sandy zones, within the sandstone pans forming the "platières". Erosion by runoff cannot be considered; the only way to hollow them out is by deflation processes. No direct dating of the Quaternary dune and loess deposits of the Fontainebleau Massif exists. Nevertheless, dating of paleopodzols interlayered between drift sands, pond deposits and bones within congelifracts allow relating these periglacial features with the end of the last glacial period. For now, there is no dating to assess what belongs to older glacial periods. Distribution of the aeolian patterns The Fontainebleau Massif displays noteworthy morphological diversities in the various districts of the forest. Some of these differentiations result from geological features, but most of them are related to erosion processes, and among them deflation processes leaved different imprints in the western and eastern districts of the Fontainebleau Massif. The topography played an important role controlling the aeolian processes. Deflation was important in the westerly upwind district. In the westerly front face, aeolian erosion was activated by turbulences around the topographic obstacles. The reliefs funneled the winds and gave rise to swirls that hollow the blowouts. This area displays the sharpest and more chiseled landforms of the massif. Moreover, the sandstone scarps at the edge of the "platières" are high and uncovered, with frequent overhangs. The collapsed sandstone blocks of the "chaos" are

  6. Effects of tillage and crop residue management on soil respiration and its mechanism%耕作方式与秸秆还田对土壤呼吸的影响及机理

    Institute of Scientific and Technical Information of China (English)

    赵亚丽; 薛志伟; 郭海斌; 穆心愿; 李潮海

    2014-01-01

    In Huang-Huai-Hai area in China, winter wheat (Triticum aestivum)/summer maize (Zea mays) rotation is the dominant two-crop-per-year cropping system. Crop residue removal and subsoil compaction have become limiting factors for yield improvement in the area. Tillage and crop residue retained are two effective ways to improve soil properties and increase crop yield. Soil tillage and crop residue retained can reduce soil bulk density, improve water storage and aeration in the soil, increase soil microorganism and enzyme activities, improve soil biological properties, thus promote plant root growth and increase crop production. However, studies in the past mainly focused on the effects of single tillage or single crop residue retained on soil respiration. There is a need currently for research in the effects of tillage, crop residue retained and their interaction on soil respiration under the two-crop-per-year cropping system. A two-year field study from 2010 to 2012 was conducted to determine effects of tillage practice and crop residue management on soil respiration, soil temperature, soil water content, soil compaction, soil organic carbon content, dry matter accumulation of plant and root in the wheat-corn double crop cropping system. The study was conducted at the Wen County Experimental Station, Henan, China. The experiment was arranged in a split-plot design with three replications. Tillage practice and crop residue management were two factors of interest. The tillage treatment was randomly assigned to main plots and crop residue treatment was randomly assigned to sub-plots. The tillage practice treatments were: moldboard plough (MP) to a maximum depth of 15 cm, deep moldboard plough (DMP) to a maximum depth of 30 cm, and chisel plough (CP) to a maximum depth of 30 cm. All three tillage treatments were implemented after corn harvested in October of 2010 and 2011. In addition to different plough treatments, all plots were disc harrowed before wheat planting

  7. Further Development Research and Countermeasures for the Tourism Resource of the National Geological and Ecological Park in Zhangzhou%漳州国家地质生态公园旅游资源的深度开发研究与对策

    Institute of Scientific and Technical Information of China (English)

    张倩倩

    2013-01-01

    After several field visits and data col ection, found the district retains the style typical of the Tertiary central volcanic eruption weathering and erosion of structural features and the topography of the late landscape. Mainly in four volcanic remains rare in the world represented, that is, columnar basalt, ancient crater, volcanic vents beaded base and basalt watermelon rind structure. This is a natural volcanic geology museum, with a high ornamental, popular and interesting. However, the concept of local tourism and weak environmental protection measures are not avant-garde and so many reasons that could have been set off in the sky, blue sea, sandy beaches, green forest into a beautiful landscape elements of these are not given to use in addition. Chisel hand here, the transformation in the design of the overal land use concept of "one, three zones, five garden"approach to the surrounding open to expansion. Ful use of existing natural beauty,embracing the green, close to nature, the use of advanced design concepts, create a pleasant and with nature, to form the leisure, tourism, entertainment, exchange of best green space. To the unique geological formations and land more harmonious growth, and ultimately meet the people back to nature, feel the natural desire for the infinite. To meet the beautiful gift of human love of nature at the same time led to the further development of the local economy can be described as a double benefit! Attempts to reach minimize adverse interference and damage to the natural human activity, to a certain extent promote the harmonious coexistence of man and nature.%经过数次的实地考察与资料收集,发现区内保留了典型的第三纪中心式火山喷发构造形迹和后期风化侵蚀的地形地貌景观。主要以四种世界罕见的火山地质遗迹为代表,即柱状玄武岩、古火山口、串珠状的火山喷气口群和玄武岩的西瓜皮构造。这是一座天然的火山地质博物馆,具

  8. Comparative study of complications among routine method,high speed turbine handpiece and piezosurgery device after extraction of impacted wisdom teeth%高速涡轮钻、超声骨刀和常规方法拔除下颌阻生智牙的比较

    Institute of Scientific and Technical Information of China (English)

    郭照中; 张恒; 李焱; 李欣; 刘荫; 王杨; 袁春霞; 刘学

    2012-01-01

    目的:通过比较常规拔牙法、高速涡轮钻、超声骨刀拔除邻近神经管下颌阻生智牙并发症的客观数据,寻求拔除此类牙的最佳方法.方法:将300例符合条件的患者随机均分为3组,A组采用骨凿、劈冠、增隙法拔牙,B组用高速涡轮钻,C组用超声骨刀拔牙.观察3组患者手术时间、术后疼痛持续时间、干槽症和下牙槽神经损伤发生情况.采用SPSS 13.0软件包对计量资料进行配对t检验,对计数资料进行x2检验.结果:手术时间A组为(14.12±0.12)min,B组为(7.22±0.15)min,C组为(25.23±0.32)min;3组间两两比较均有显著差异(P<0.05).术后疼痛持续时间A组为(62.15±1.51)h,B组为(48.23±1.23)h,C组为(14.34±0.80)h;3组间两两比较均有显著差异(P<0.05).干槽症发生例数A组为9例,B组为2例,C组为1例.下牙槽神经损伤A组6例,B组2例,C组0例.结论:与常规拔牙方法相比,高速涡轮钻拔除复杂阻生牙能缩短手术时间,减少术后并发症,超声骨刀和前2种方法相比虽然手术时间较长,但术后并发症更少.%PURPOSE: To investigate complications in extraction of complicated impacted wisdom teeth whose root apex near to the inferior alveolar nerve (IAN) by using routine method (chisels),high speed turbine handpiece and piezosurgery device respectively. METHODS: Three hundred qualified patients with impacted wisdom teeth were divided into three groups randomly,one hundred patients in group A were extracted by routine method, one hundred patients in group B were extracted by high speed turbine handpiece , and one hundred patients in group C were extracted by piezosurgery device. The operation time,postoperative pain duration,dry socket and IAN injury were compared between each two groups. All statistical analysis was performed using SPSS 13.0 software package. Differences between groups were compared using a paired t test (quantitative data) or Chi-square test (qualitative data). RESULTS: The

  9. Controlo da salinidade do solo com recurso à sementeira directa Control of the soil salinity by using direct drilling

    Directory of Open Access Journals (Sweden)

    J. P. Mendes

    2009-01-01

    mais baixos de condutividade eléctrica da solução do solo ao fim de dois anos são indicadores, de que, a sementeira directa, em conjunto com uma cultura de cobertura, poderá ser uma ferramenta útil na prática de uma agricultura de regadio sustentável, em clima semi-árido e em solos de baixa condutividade hidráulica, mesmo utilizando águas de rega com condutividade eléctrica (CE moderada.The use of water with moderated salt content for irrigation under semi-arid conditions, especially on soils with low saturated hydraulic conductivity, can lead to an increase of the salt content of the soil and even to an increase of exchangeable Na. This is a possible scenario in the Alqueva irrigation program in the South of Portugal. The present study aims to evaluate the potential of direct drilling and soil mulching as a way to improve infiltration and reduce evaporation, in order to reduce salt accumulation during the summer and to improve leaching during the winter. The trial has been carried out on a Calcic Luvisols (FAO classification under centre pivot irrigation. There were used two soil tillage treatments (direct drilling and traditional - chisel plow plus two disc arrows, two levels of water salinity (0.7 dS m-1 and 2 dS m-1 and two water regimes (100% and 70% of Etc. The experimental design is a split plot, with tillage as the reference treatment. After the second year the salinity in the top 0.20 m of the soil is lower under direct drilling (0.63 dS m-1 than under traditional tillage system (0.75 dS m-1. The differences between tillage treatments are more evident for the higher water regime. The lowest values of electric conductivity in soil solution at the end of two years, indicate that direct drilling together with cover crop, can be a useful tool in irrigation under semi-arid conditions, in soils with low values of hydraulic conductivity, even when using water with moderated electrical conductivity (EC.

  10. 椎弓根螺钉置入内固定与单纯椎管减压治疗退行性腰椎滑脱的比较%Comparison of pedicle screw fixation and simple vertebral canal decompression in the treatment of lumbar degenerative spondylolisthesis

    Institute of Scientific and Technical Information of China (English)

    刘保华; 王沛; 夏群; 冯世庆; 郑永发; 李冰

    2011-01-01

    of pedicle screw fixation and fusion in treatment of degenerative spondylolisthesis, and to compare with simple vertebral canal compression.METHODS: A total of 38 patients with lumbar degenerative spondylolisthesis received treatment at the Department of Orthopaedics, General Hospital of Tianjin Medical University were selected, and 3 patients were lost in follow-up. Of the remaining 35 cases, 21 cases underwent pedicle screw fixation posterolateral fusion and 14 cases underwent simple vertebral canal decompression. Simple vertebral canal compression group treated with the rongeur bite yellow ligament and lamina to relieve nerve root compression, forward vertebral slippage of adjacent vertebral body with posterior inferior formation relative prominence was chiseled with osteotome. According to Wein-stein method pedicle screw into the needle localization, then screw into the pedicle screw and undergo vertebral plate decompression on the basis of compression condition in pedicle screw fixation and fusion group. The clinical effect underwent comprehensive evaluation of oswestry dysfunction index; horizontal displacement and angular displacement were observed at hyperextension and flexion time. Degenerative condition of adjacent segment was evaluated by UCLA system.RESULTS AN D CONCLUSION : A total of 35 patients were followed up for 1 year. The excellent rate in pedicle screw fixation and fusion group was significantly higher than that in simple vertebral canal compression group (P < 0.05). Pedicle screw fixation and fusion has little effect on the stability of lumbar. There was no significant change in adjacent segment before degenerative insertion and 1 year after insertion. Simple vertebral canal compression had a significant effect on the stability of lumbar, and there was no significant change in adjacent segment degeneration before treatment and 1 year after treatment. It is indicated that pedicle screw fixation and fusion has satisfying effects in treatment of

  11. Aspectos econômicos do uso de fontes orgânicas de nutrientes associadas a sistemas de preparo do solo Economical aspects of organic nutrient sources associated with soil tillage systems

    Directory of Open Access Journals (Sweden)

    Carla Maria Pandolfo

    2008-09-01

    ário, P e K, após nove anos de aplicação das fontes de nutrientes, tem importante participação no desempenho econômico das mesmas.Economical analysis is important to make decision on the use of organic nutrient sources. The objective of this study was to elaborate an economical analysis of different nutrient sources to help farmers and technicians to make decision about the use of these sources at different soil management. The study was carried out at the Epagri Experimental Station of Campos Novos, using a long-term experiment. The treatments were a combination of five tillage systems (no-till; chisel plow; conventional tillage; conventional tillage with crop residues burned and conventional tillage with crop residues removed from the field, with four nutrient sources (TES=control, no fertilizer; AM=mineral fertilizer according with technical recommendation for each crop; EA=5mg ha-1 of moisture poultry litter; ELB=60m³ ha-1 of liquid cattle manure; and ELS=40m³ ha-1 of slurry pig manure. The economical attributes used were variable costs of production, total income, and the cost of the necessity of lime and fertilizers application to improve soil chemical condition after nine years of applying treatments. A model was used to quantify and analyse the effect of nutrient sources in economical aspects, for each nutrient source within each soil tillage. The outputs were triangular pictures and their areas with 90% confidence limits. It was concluded that economical aspect effects of the organic nutrient sources were dependent on tillage systems, and the better performance was in no-till system. EA and ELS showed better economical results. ELS and ELB, even showing different picture areas, were the sources that showed lesser variability in economical attribute evaluated, and did not have one highlight attribute among them. The use of cost of the necessity of lime and fertilizers application to improve soil chemical condition after nine years of applying treatments

  12. Relações da rugosidade superficial do solo com o volume de chuva e com a estabilidade de agregados em água Relations of soil surface roughness with the rainfall volume and water aggregate stability

    Directory of Open Access Journals (Sweden)

    Ildegardis Bertol

    2006-06-01

    -se inversamente com o volume das chuvas naturais. O decaimento máximo da rugosidade ao acaso relacionou-se inversamente com o DMP e com o DMG dos agregados estruturais.Soil surface roughness is, among other factors, affected by soil tillage, cumulative rainfall and aggregate stability in relation to destructive water action. The soil surface roughness of a soil classified as a Haplumbrept was evaluated in an area where a water erosion experiment under natural rainfall has been carried out over the course of 15 years in the South of the Planalto Catarinense, Santa Catarina State, Brazil. The soil microrelief was characterized by the indices: roughness (RR, tortuosity (T and limiting elevation difference (LD and was measured in 2003 in a corn crop, and in 2004 in an oat crop (cumulative rainfall during the experimental periods was 229 and 350 mm, respectively. Moreover, water aggregate stability was evaluated and expressed by the mean weight diameter (DMP and mean geometric diameter (DMG of aggregates between the two crops, in 2004. The studied soil tillage system treatments were: plowing plus disking (PC, chisel plow plus disking (CM, and no-tillage (SD, both under corn and oat crops. One additional treatment used as reference consisted of bare soil tillage with plowing plus disking (SC. The surface roughness was evaluated five times under corn and four times under oat. The first evaluation was carried out immediately after soil tilling and the others every other week. The initial values of the RR, T, and LD indices were high and decreased with increasing rainfall on SC, PC AND CM treatments, while in the SD treatment the afore-mentioned indices were only high for oat and varied very little as the rainfall increased. The reduction in the random RR index was the highest in the BS treatment, while the lowest reduction occurred in the SD treatment. The values of all indices under study were reduced in comparison to that of the original microrelief condition, where the slope effects

  13. Effect of blade vibration on mulch tillage performance under silt clay loam soil

    Directory of Open Access Journals (Sweden)

    B Goudarzi

    2015-09-01

    Full Text Available Introduction: Mulch tillage system is an intermediate system which covers some of disadvantages of no tillage and conventional tillage systems. In farms in which tillage is done with a chisel plow, runoff and soil erosion have a less important relation to moldboard and disk plow and naturally absorption of rainfall will be developed. Thus, the mulch tillage system is an appropriate alternative to conventional tillage and no tillage (Backingham and Pauli, 1993. The unwanted vibration in machinery and industry mainly processes most harmful factors, for example: bearing wear, cracking and loosening joints. And noise is produced in electrical systems by creating a short circuit (Wok, 2011. Self-induced and induced vibration are used in tillage systems. Induced vibration is created by energy consumption and self-induced vibration is created by collision among the blades and soil at the shank (Soeharsono and Setiawan, 2010. A study by Mohammadi-gol et al. (2005 was conducted. It was found that on the disk plow, plant residues maintained on the soil are more than that of moldboard plow. 99% frequency and amplitude, speed and rack angle of blade directly affect soil inversion and indirectly affect preservation of crop residue on the soil. The effect of vibration frequency and rack angle of blade to reduce the tensile strength is also clear. Moreover, in contrast to previous studies when speed progressing is less than (λ, not only the relative speed (λ, but also frequency can reduce the tensile strength (Beiranvand and Shahgoli, 2010; Awad-Allah et al., 2009. Therefore, aim of this study was to determine the effect of vibration and the speed of tillage on soil parameters and drawbar power in using electric power. Materials and Methods: To perform this test, three different modes of vibration (fixed, variable and induced vibration and two levels of speed in real terms at a depth of 20 cm were used for farming. The test was performed with a split plot

  14. Teoria laneana: a univocidade radical aliada à dialética-materialista na criação da psicologia social histórico-humana Lanean theory: the radical unambiguousness allied with the dialectic-materialist in creating historical-human social psycology

    Directory of Open Access Journals (Sweden)

    Bader Burihan Sawaia

    2007-01-01

    sua concepção-compromisso de ciência em busca do conhecimento da existência humana sem suturas.The paper presents the base of Sílvia Lane's theoretical-methodological work, highlighting its ontological and epistemological presumptions and delineating the grand moments of its configuration process. The dialectic process that advances incorporating new knowledge without abandoning the previous, but uniting it in producing something new. This "pragmatic-critical-revolutionary" methodology, initially intuitive, became scientifically chiseled out from empirical research, according to Lane, fundamental for criticizing the concepts and advancing the theory. The task of the text is easy because Sílvia registered in her books each change of her principal interests, analytical categories and philosophical reflections. There are four moments to be highlighted. All of them make a profound study of her radical theoretical overcome: the transition of a configured reference in the interface between Lewin, Mead, Skinner to Marxism: 1 from the 70's, marked by the privileged dialogue with representations theory and with concerns with language and social groups; 2 from the 80's, a time of vigorous reflections on a new conception of man for psychology, with emphasis on the categories of consciences and alienation, orientated by soviet psychology and neo-marxism (Politzer and Heller; 3 from the 90's, characterized by the reflection on the role of subjectivity/affectivity on social awareness and on transformative action, overcoming the subject's imprisonment to exteriority and to pure repetition and the purge of singularity, and by reaffirming participant research and community praxis; 4 from the new millennium, dedicated to unveil the secrets of human creativity. Emotion, art and creativity were the themes that became to mediate her incessant critical thoughts on psychology's theories and practical consequences for Latin America's social condition. Thus, this paper hopes to present

  15. Intervalo hídrico ótimo no perfil explorado pelas raízes de feijoeiro em um latossolo sob diferentes níveis de compactação Least limiting water range in an oxisol profile penetrated by common bean roots under different compaction levels

    Directory of Open Access Journals (Sweden)

    Douglas Rodrigo Kaiser

    2009-08-01

    clayey Oxisol. Soil samples with preserved structure were collected in an experiment with three levels of soil compaction: NT - continuous no-tillage for six years, NTc - no-tillage with additional compaction and Chi - chisel plowing on previous no-till soil. To determine soil penetration resistance 107 samples were collected in the 0-0.20 m layer, at different soil moisture levels, whereas for the soil water retention curve samples were collected in the layers 0-0.05, 0.05-0.10, 0.10-0.15, 0.20-0.25 and 0.30-0.35 m. The adjusted soil penetration resistance model, based on bulk density and soil moisture, explained 33 % of the variation observed in soil penetration resistance and all parameters were significant in this adjustment. The critical bulk density of the LLWR depends on the value of limiting soil penetration resistance, which was 1.36, 1.40, 1.45, and 1.49 Mg m-3 for the RP values of 1.5, 2.0, 2.5, and 3.0 MPa, respectively. Soil aeration became limiting when densities exceeded 1.32 Mg m-3. Soil compaction reduced LLWR in the layers around 0.10 m. At a critical resistance of 2 MPa, LLWR was zero in the layer 0.05-0.12 m for NT, in 0.05-0.17 m for Chi, and between 0.03 and 0.22 m for NTc. The use of 3 MPa as critical resistance resulted in positive LLWR value in deeper soil layers, and was zero only in the 0.05-0.15 m layer of the NTc. Common bean roots did not grow in the soil layer where the LLWR was zero with a critical resistance of 3 MPa.

  16. MANEJO DO SOLO E SUAS RELAÇÕES COM A ACIDEZ E A DISPONIBILIDADE DE MICRONUTRIENTES SOIL AND MICRONUTRIENT ACIDITY AVAILABILITY AS AFFECTED BY SOIL MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Renato Sérgio Mota dos Santos

    2007-09-01

    Helena, state of Goiás, Brazil, with soybean, corn, rice and common bean crops under four soil management: 1 no-till; 2 deep moldboard plowing; 3 shallow harrow plowing and 4 deep stirring, using a chiseling plow and three levels of fertilization: 1 Check; 2 State recommendation and 3 Fertilizers to cover the nutrients extracted by grain exportation. The distribution of exchangeable aluminum was influenced by soil management in function of machines and implements demanded by each system. The areas submitted to no-till management presented higher aluminum concentration in the superficial layer after the first crop, but the same was observed in the areas submitted to deep stirring only after the last crop. The areas submitted to shallow harrow plowing showed similar results of those obtained by deep moldboard plowing , even so in smaller degree. In the area where deep moldboard plowing was used, aluminum concentration was similar in all soil layers. Higher pH values were observed on the superficial layer of soil submitted to deep moldboard plowing in relation to no-till shallow harrow plowing and deep stirring. Uniform distribution of iron and manganese was observed in areas submitted to deep moldboard plowing. No variation was observed in relation to fertilizer application.

    KEY-WORDS: Soil fertility; micronutrients; no-till; crop systems.

  17. Efecto acumulativo de la siembra directa sobre algunas características del suelo en la región semiárida central de Argentina Long term effect of no-tillage on some soil properties in the central semiarid region of Argentina

    Directory of Open Access Journals (Sweden)

    Adriana Abril

    2005-12-01

    recent adoption of no-tillage practices in the country. Moreover, most of the available research on no-tillage in Argentina refers to the humid Pampas region. In contrast, information on the semi-arid region is very scarce, despite the fact that an increased cover stubble is particularly useful in water-limited soils. In this paper we report a long-term evaluation (5 and 10 years periods of no-tillage practices on a chemical (SOM, total N and NO3-N and biological (microbial biomass and activity soil characteristics, and b quantity, identifiable fractions, and chemical quality of stubble material in soybean monoculture and soybean-corn rotation. Research was conducted at Manfredi INTA Experimental Station in semi-arid, central Argentina (31°49' S and 63°46' W. Soils under no-tillage system had higher SOM and total N content compared with control (conservation tillage with chisel plow in both, soybean monoculture and soybean-corn rotations. The observed difference increased with time (10 and 20% at 5 and 10 years, respectively. Nitrate content, and microbial activity and biomass showed high variability in the measurement periods, depending on climatic condition at the sampling date. Stubble cover was greater in the corn-soybean rotation with corn as preceding crop (2473.9 g m-2 than in soybean monoculture (1035.7 g m-2. The stubble non-identifiable fraction was very significant in all treatments (ranging between 2-10 t ha-1, which would favor new surface soil formation. The soybean-corn rotation with soybean as preceding crop showed the lowest values in all chemical parameters, particularly in soluble compounds (nitrate, ammonium and soluble carbon. Contrarily with what is usually assumed, our results suggest that nutrient release from long-term stubble may become a significant nutrient source for the crops. Therefore, this nutrient source should be considered when evaluating crop fertilization requirements.

  18. Perdas de fósforo e potássio por erosão hídrica em um inceptisol sob chuva natural Phosphorus and potassium losses by water erosion in an inceptisol under natural rainfall

    Directory of Open Access Journals (Sweden)

    I. Bertol

    2004-06-01

    , accelerating environmental degradation. The P and K losses caused by water erosion were evaluated from November 1999 to October 2001 in an Inceptisol with 0.102 m m-1 slope, in Lages, Santa Catarina State, Brazil, under natural rainfall conditions. The evaluated soil management systems were: no-tillage for six years (NT6, no-tillage for nine years (NT9, chiseling plus one disking for nine years (C + D9, and plowing plus disking twice for nine years (P + D9. All of these treatments were carried out in duplicate. One experimental plot was cultivated with bean, vetch, corn, and oat in rotation, and the other with soybean, wheat, soybean, and wheat in succession. An additional treatment consisted of bare soil (control, which was periodically tilled with plowing plus disking twice for nine years (BS9. The P and K contents were determined in runoff water and sediments. Both P and K concentrations were higher in runoff water and sediments under the conservation soil tillage than under conventional soil tillage. Total K losses were higher in the runoff water than in the sediment, except in the BS9 treatment. Regarding P losses, they were higher in water than sediment only in the NT6 and NT9 tillage. In the runoff water, the total P losses were higher in NT6 and NT9 tillage, while the K losses varied with conservational tillage and conventional tillage, with no clear trend. Potassium losses in the runoff sediment were smaller in conservational tillage, but those of P were only smaller in NT6 and NT9 treatments.

  19. 40 Years of Processing Pieces of Space

    Science.gov (United States)

    Satterwhite, C. E.; Funk, R. C.; Righter, K.; Harrington, R. H.

    2016-01-01

    representative sample, either a 1-3 gram chip or thin section is sent to the Smithsonian Institution for classification. After Antarctic meteorites have been classified and approved by the Nomenclature Committee of the Meteoritical Society, they are announced in the Antarctic Meteorite Newsletter, which is published twice per year (fall and spring) so that scientists may review which meteorites are available to study. Requests for Antarctic Meteorite samples are welcomed from research scientists, regardless of their current state of funding for meteorite studies. Since its inception over 3,300 requests have been made for pieces of these meteorites and over 400 investigators worldwide are active in the study of meteorites.. Research on these samples has been published in more than1500 peer reviewed articles; a listing of papers for any meteorite sample can be generated by accessing http://curator.jsc.nasa.gov/antmet/referencesearch.cfm. Antarctic meteorite samples requested by scientists are prepared several different ways. Most samples are prepared as chips, either using a rock splitter or using a chisel and chipping bowl. In special situations, a researcher may request a meteorite slab in which case the samples are cut using a diamond-bladed bandsaw inside of a dry nitrogen glove box. The meteorites are always cut in a 100 percent liquid-free environment. Additionally, thin/thick sections of Antarctic meteorites are also prepared at JSC. The meteorite thin section lab at JSC can prepare standard 30-micron thin sections, thick sections of variable thickness (100 to 200 microns), or demountable sections using superglue, all section are prepared without using water. Although many of the techniques used back in the '70's are still used today, advances in computers, software, databases, available tools and instrumentation have helped to streamline and shorten the duration of the classification process. In conjunction with present day missions to asteroids and other planets

  20. Efeitos de sistemas de preparo nas propriedades físicas de um Latossolo Vermelho distrófico Effects of tillage systems on the soil physical properties of a dystrophic Red Latosol

    Directory of Open Access Journals (Sweden)

    Karina Maria Vieira Cavalieri

    2006-02-01

    residue management are essential for the sustainability of cassava production in sandy and sandy loam soils of Northwestern Paraná State, Southern Brazil. The objective of this study was to evaluate the effects of different tillage systems used for planting cassava: no-tillage (NT, minimum tillage using chiseling (MT and conventional tillage with moldboard plow and disking (CT on some physical properties of a dystrophic Red Latosol. The following soil physical properties were evaluated in the 0-0.15 m and 0.15-0.30 m soil layers: soil bulk density (BD, soil water retention curve, soil resistance to penetration curve and least limiting water range (LLWR. Higher values of BD and soil resistance to penetration were verified in the NT and MT treatments. The soil water retention curve was only influenced by BD, which incorporated the effects of the soil tillage systems independent of sampled layers. The soil resistance curve to penetration was influenced by tillage systems and layers, indicating that the soil resistance to root penetration was higher in NT > MT > CT, and was accentuated at the 0.15-0.30 m depth. The increase in the BD led to a reduction in the LLWR due to the effects of soil resistance to penetration and air-filled porosity, which in turn determined the range of soil available water. Results indicated that LLWR value followed the sequence: PC = PM > PSR in the 0-0.15 m soil layer, and was not influenced by tillage systems in the 0.15-0.30 soil layer The critical bulk density value (BDc, the BD value at which LLWR = 0, was lower in NT and MT tillage systems compared with CT, therefore resulting in a smaller frequency of higher BD values than BDc in the soil under CT.

  1. The barley straw residues avoid high erosion rates in persimmon plantations. Eastern Spain

    Science.gov (United States)

    Cerdà, Artemi; González Pelayo, Óscar; Giménez-Morera, Antonio; Jordán, Antonio; Novara, Agata; Pereira, Paulo; Mataix-Solera, Jorge

    2015-04-01

    distributed soil erosion and sediment delivery model (WATEM/SEDEM) in Northern Ethiopia. Land Degradation & Development 24, 188-204. DOI 10.1002/ldr.1121 Lavigne, C., Achard, R., Tixier, P., Lesueur Jannoyer, M. 2012. How to integrate cover crops to enhance sustainability in banana and citrus cropping systems. Acta Horticulturae 928, 351-358. Le Bellec, F., Damas, O., Boullenger, G., Vannière, H., Lesueur Jannoyer, M., Tournebize, R., Ozier Lafontaine, H. 2012. Weed control with a cover crop (Neonotonia wightii) in mandarin orchards in Guadeloupe (FWI). Acta Horticulturae 928, 359-366. Liu, Y., Tao, Y., Wan, K.Y., Zhang, G.S., Liu, D.B., Xiong, G.Y., Chen, F. 2012. Runoff and nutrient losses in citrus orchards on sloping land subjected to different surface mulching practices in the Danjiangkou Reservoir area of China. Agricultural Water Management 110, 34-40. Lu, J., Wilson, M.J., Yu, J. 1997. Effects of trench planting and soil chiselling on soil properties and citrus production in hilly ultisols of China Soil and Tillage Research 43, 309-318. Lü, W., Zhang, H., Wu, Y., Cheng, J., Li, J., Wang, X. 2012. The impact of plant hedgerow in Three Gorges on the soil chemicophysical properties and soil erosion. Key Engineering Materials 500 142-148. Liu, Y., Tao, Y., Wan, K.Y., Zhang, G.S., Liu, D.B., Xiong, G.Y., Chen, F. 2012. Runoff and nutrient losses in citrus orchards on sloping land subjected to different surface mulching practices in the Danjiangkou Reservoir area of China. Agricultural Water Management 110, 34-40. Lu, J., Wilson, M.J., Yu, J. 1997. Effects of trench planting and soil chiselling on soil properties and citrus production in hilly ultisols of China Soil and Tillage Research 43, 309-318. Lü, W., Zhang, H., Wu, Y., Cheng, J., Li, J., Wang, X. 2012. The impact of plant hedgerow in Three Gorges on the soil chemicophysical properties and soil erosion. Key Engineering Materials 500 142-148. Mahmoud, E., Abd El-Kader, N. 2014. Heavy metal immobilization in

  2. Extreme soil erosion rates in citrus slope plantations and control strategies. A literature review

    Science.gov (United States)

    Cerdà, Artemi; Ángel González Peñaloza, Félix; Pereira, Paulo; Reyes Ruiz Gallardo, José; García Orenes, Fuensanta; Burguet, María

    2013-04-01

    approach. Catena, 85 (3), 231-236. Cerdà, A., Jurgensen, M.F., Bodi, M.B. 2009. Effects of ants on water and soil losses from organically-managed citrus orchards in eastern Spain. Biologia, 64 (3), 527-531. Cerdà, A., Morera, A.G., Bodí, M.B. 2009. Soil and water losses from new citrus orchards growing on sloped soils in the western Mediterranean basin. Earth Surface Processes and Landforms, 34 (13), 1822-1830. Lavigne, C., Achard, R., Tixier, P., Lesueur Jannoyer, M. 2012. How to integrate cover crops to enhance sustainability in banana and citrus cropping systems. Acta Horticulturae, 928, 351-358. Le Bellec, F., Damas, O., Boullenger, G., Vannière, H., Lesueur Jannoyer, M., Tournebize, R., Ozier Lafontaine, H. 2012. Weed control with a cover crop (Neonotonia wightii) in mandarin orchards in Guadeloupe (FWI). Acta Horticulturae, 928, 359-366. Liu, Y., Tao, Y., Wan, K.Y., Zhang, G.S., Liu, D.B., Xiong, G.Y., Chen, F. 2012. Runoff and nutrient losses in citrus orchards on sloping land subjected to different surface mulching practices in the Danjiangkou Reservoir area of China. Agricultural Water Management, 110, 34-40. Lu, J., Wilson, M.J., Yu, J. 1997. Effects of trench planting and soil chiselling on soil properties and citrus production in hilly ultisols of China Soil and Tillage Research, 43 (3-4), 309-318. Lü, W., Zhang, H., Wu, Y., Cheng, J., Li, J., Wang, X. 2012. The impact of plant hedgerow in Three Gorges on the soil chemicophysical properties and soil erosion. Key Engineering Materials, 500, 142-148. Wang, L., Tang, L., Wang, X., Chen, F. 2010. Effects of alley crop planting on soil and nutrient losses in the citrus orchards of the Three Gorges Region. Soil and Tillage Research, 110 (2), 243-250. Wu J., Li Q., Yan L. 1997. Effect of intercropping on soil erosion in young citrus plantation - a simulation study. Chinese Journal of Applied Ecology, 8 (2), 143-146. Wu, D.-M., Yu, Y.-C., Xia, L.-Z., Yin, S.-X., Yang, L.-Z. 2011. Soil fertility indices of citrus

  3. CUSTOS E RENTABILIDADE DO MILHO EM FUNÇÃO DO MANEJO DO SOLO E DA ADUBAÇÃO NITROGENADA MAIZE COSTS AND PROFITABILITY ACCORDING TO SOIL MANAGEMENT AND NITROGEN FERTILIZATION

    Directory of Open Access Journals (Sweden)

    Flávio Hiroshi Kaneko

    2009-12-01

    ="font-style: normal;">PALAVRAS-CHAVE: Zea mays; custo de produção; plantio direto; plantio convencional.

     

    Agronomic practices that help farmers to raise yield and reduce costs must be studied to ensure agricultural sustainability. Thus, the objective of this study was to analyze economically the effect of soil management and nitrogen fertilization in maize crops. Treatments consisted of a combination of 3 soil management techniques (plow harrows + floating harrows, chisel + floating harrows, and no-tillage, 5 periods of nitrogen fertilization (control - 0 kg ha-1 N; 120 kg ha-1 after sowing (S; 120 kg ha-1 in the V6 stage; 30 kg ha-1 (S + 90 kg  颞下颌关节继发性强直与幼年期髁状突纵行骨折的关系%Relationship between secondary ankylosis of temporomandibular joint and childhood longitudinal fracture of mandibular condyle

    Institute of Scientific and Technical Information of China (English)

    姚军; 周继林; 胡敏; 洪民; 王燕一

    2005-01-01

    论:幼年期髁突纵行骨折对TMJ造成严重继发性损伤,髁突纵行骨折与关节强直关系密切.%BACKGROUND: Much attention has been focused on mandibular condyle fracture, which has long been considered as a severe injury to the temporomandibular joint(TMJ). Restricted by diagnostic methods, many studies have been conducted on transverse fracture whereas little attention has been paid to longitudinal fracture of the mandibular condyle. Even less is known about longitudinal fracture in young children.OBJECTIVE: To evaluate the effects of childhood longitudinal fracture of the mandibular condyle on secondary ankylosis of TMJ.DESIGN: A randomized controlled study.SETTING: Department of Stomatology, General Hospital of Chinese PLA.MATERIALS: The experiment was completed in the Center for Experimental Animals, General Hospital of Chinese PLA. Twelve young Chinese experimental miniature pigs bred by the Institute of Experimental Animals, Beijing Agriculture University, aged 2 -3 months and weighing(5 -5.5) kg, were used and raised with mixed feed, and then divided into 3 groups randomly.METHODS: Food and water was forbidden for the miniature pigs 12 hours before operation. Under anesthesia with(5.0 - 15.0) mg/kg ketamine/xylazine abdominally injected, conventional disinfection was performed in the right lateral decubitus position and layer-by-layer preauricular incisions were made on the left side of the miniature pigs. The joint cyst was incised transversely and the lower cavity of TMJ was exposed and dragged downwards. The mandibular condyle was cleaved into two vertically along the inner 1/3 part of it with a 5.0 mm-wide bone chisel to cause inferior and posterior sagittal fractures. The miniature pigs were executed 3 months and 6 months after operation, and their condyles were cut for observation.MAIN OUTCOME MEASURES:①The morphological changes of mandibular condyle specimens in the three groups observed with the naked eyes.②The pathological

  4. STUDY ON STONE ARTIFACT RESOURCE CATCHMENTS IN THE XIAOHUANGSHAN SITE,ZHEJIANG PROVINCE%浙江嵊州小黄山遗址石制品资源域研究

    Institute of Scientific and Technical Information of China (English)

    何中源; 张居中; 杨晓勇; 王海明; 张恒

    2012-01-01

    valley takes shape in mountainous areas,thus it is conjectured that those raw materials could be brought from the mountain area to the Xinsheng Basin. According to the present stream network of watershed,it is inferred that most of raw materials could be easily obtained from Chongren River,ca. 320m north of the site and the Changle River, ca. 1400m southeast of the site. However,more attention must be paid to sources of stones,it is proposed that ancient people obtained basalt mainly from the Chongren River, while shale and granite only can be found in Changle River, and the rest raw materials can be obtained from both rivers. All these foundings indicate that Xiaohuangshan people had a good knowledge and sense of selectivity on different kinds of rocks.Relationships between stone artifacts and lithology of raw materials were also examined in this paper. About 88. 8% of grinding slabs and hand-stones were made of basalt, they differ sharply from many sites' grinding tools made on sandstones. Many tools which were edged,such as stone axes,adzes and chisels were made of diabase or shale. Chalcedony was made into stone bails almost. Such differences prove that Xiaohuangshan people had some empirical knowledge on properties of different lithic raw materials, and they were able to select different materials to produce a variety of implements.To sum up,the analysis of Stone Artifact Resource Catchments in the Xiaohuangshan Site shows that collecting rock pieces from rivers around the site was the principal strategies of raw material exploitation adopted by the Xiaohuangshan people. They chose different kinds of rock pieces collected from the river bed as raw materials and they also had an empirical knowledge on properties of different rocks. The choosing for basalt to make grinding slabs may be related to people's favorable characteristics, however, this assumption requires more evidences.%本文采用“遗址内”(on-site)的资源域分析方法,通过对小黄山遗址

  5. The use of straw mulch as a strategy to prevent extreme soil erosion rates in citrus orchard. A Rainfall simulation approach

    Science.gov (United States)

    Cerdà, Artemi; Giménez-Morera, Antonio; Jordán, Antonio; Pereira, Paulo; Novara, Agata; García-Orenes, Fuensanta

    2014-05-01

    -115. 10.1016/j.still.2010.05.005. García-Orenes, F., Roldán, A., Mataix-Solera, J., Cerdà, A., Campoy, M., Arcenegui, V., Caravaca, F. 2012. Soil structural stability and erosion rates influenced by agricultural management practices in a semi-arid Mediterranean agro-ecosystem. Soil Use and Management 28, 571-579. DOI: 10.1111/j.1475-2743.2012.00451.x Haregeweyn, N., Poesen, J., Verstraeten, G., Govers, G., de Vente, J., Nyssen, J., Deckers, J., Moeyersons, J. 2013. Assessing the performance of a Spatially distributed soil erosion and sediment delivery model (WATEM/SEDEM) in Northern Ethiopia. Land Degradation & Development 24, 188-204. DOI 10.1002/ldr.1121 Iranzo, M., Cañizares, J.V., Roca-Perez, L., Sainz-Pardo, I., Mormeneo, S., Boluda, R. 2004. Characteristics of rice straw and sewage sludge as composting materials in Valencia (Spain). Bioresource Technology 95, 107-112 Le Bellec, F., Damas, O., Boullenger, G., Vannière, H., Lesueur Jannoyer, M., Tournebize, R., Ozier Lafontaine, H. 2012. Weed control with a cover crop (Neonotonia wightii) in mandarin orchards in Guadeloupe (FWI). Acta Horticulturae 928, 359-366. Liu, Y., Tao, Y., Wan, K.Y., Zhang, G.S., Liu, D.B., Xiong, G.Y., Chen, F. 2012. Runoff and nutrient losses in citrus orchards on sloping land subjected to different surface mulching practices in the Danjiangkou Reservoir area of China. Agricultural Water Management 110, 34-40. Lu, J., Wilson, M.J., Yu, J. 1997. Effects of trench planting and soil chiselling on soil properties and citrusproduction in hilly ultisols of China Soil and Tillage Research 43, 309-318. Lü, W., Zhang, H., Wu, Y., Cheng, J., Li, J., Wang, X. 2012. The impact of plant hedgerow in Three Gorges on the soil chemicophysical properties and soil erosion. Key Engineering Materials 500 142-148. Robichaud, P.R., Lewis, S.A., Wagenbrenner, J.W., Ashmun, L.E., Brown, R.E. 2013a. Post-fire mulching for runoff and erosion mitigation. Part I: Effectiveness at reducing hillslope erosion rates

  6. SUSTAINABILITY EFFECTS OF Crotalaria juncea L. AND Crotalaria spectabilis ROTH ON SOIL FERTILITY AND SOIL CONSERVATION

    Science.gov (United States)

    László, Márton, ,, Dr.

    2010-05-01

    fertility. The first set of actions, such as lime application, erosion control measures, and chiseling of sub-surfacehardpan, are "one time" investments which often benefit not only the farming communities but also society at large, improved water quality, food security, etc. Costsharing among all beneficiaries in society should be the carefully thought about. The second set of actions relates to the protection and or maintance of the enhanced soil capital, through balanced plant nutrition applications, appropriate crop rotations, etc., the cost of which have definitely to be fully supported by farmers. However, farmers will bear these costs only if the economic, institutional and legal frame conditions are favourable, i. e. when there are enough incentives to reinvest instead of consuming the capital stock. Possible interventions to enhance soil fertility management, therefore, range from policies affecting farm gate prices, security of land use, access to credit, access to markets, relations between input and output prices, fertilizer supply and distribution right through to access to information on improved soil fertility management (soil organic matter management, prevention of nutrient losses by run off - leaching, efficient use of fertilizers). This cannot be obtained with isolated measures and projects but requires a coherent strategy for soil fertility enhancement and sustainable soil management (Janssen 1993). The implementation of such a strategy, finally, requires a strong commitment of national governments which was often lacking in the past, as well as support from the international community. Neither human needs are satisfied, especially food demands, nor are the natural resources protected. Gross plant production was decreased with twenty percent in the last 10 years. Morever, this inadequate rate is obtained partly by degradation of the environment resulting from overexploiting of soil resources. The reversal of this trend and a sustained increase of