48 research outputs found
KORELASI PERCEPATAN TANAH MAKSIMUM DAN ANALISIS FAULT FRACTURE DENSITY (FFD) TERHADAP POTENSI LONGSOR DI CIANJUR JAWA BARAT
No full textPeristiwa gempa bumi telah menimbulkan dampak negatif diantaranya adalah pemicu bencana longsor yang tidak mudah untuk diidentifikasi. Salah satu daerah yang telah terindikasi memiliki potensi longsor yang tinggi adalah daerah Cianjur, hal ini dilihat dari keberadaan faktor-faktor pemicu longsor di daerah tersebut. Oleh karenanya dibutuhkan mitigasi bencana longsor akibat gempa bumi untuk mengurangi kerugian. Sehingga dalam penelitian ini dilakukan studi korelasi dua faktor pemicu longsor yaitu gempa bumi yang diinterpretasikan oleh percepatan tanah maksimum dan keberadaan zona sesar yang diidentifikasi oleh fault fracture density (ffd). Setelah korelasi tersebut dilakukan menggunakan analisis statistik regresi linier langkah selanjutnya adalah memverifikasi adanya potensi longsor dengan menggunakan analisis citra fotogrametri dengan algoritma Chan-Vese. Berdasarkan perhitungan percepatan tanah maksimum di Cianjur terungkap bahwa kisaran nilai sekitar 5.518 gal hingga 5.550 gal, nilai tertinggi ditemukan di Cidaun. Sedangkan, analisis ffd menunjukkan bahwa zona sesar dan rekahan di Cianjur menghasilkan tiga kelompok kelas densitas; tinggi 143-238 km / km2, densitas sedang 95-134 km / km2, dan rendah 0-95 km / km2. Kemudian hasil statistik menunjukan korelasi positif antara kedua subjek yang berarti informasi tentang ffd dapat dijelaskan oleh percepatan tanah dan telah terverifikasi menggunakan algoritma Chan-Vese yang menghasilkan background gambar dan objek tersegmentasi yang secara khusus menunjukkan adanya zona potensial longsor. Sehingga dapat disimpulkan bahwa hasil korelasi dan validasi ini telah berhasil dengan memuaskan mengkategorikan lima kelas potensi longsor di Cianjur yaitu; kelas sangat tinggi, tinggi, sedang, rendah dan sangat rendah. Tak dapat dipungkiri bahwa riset ini dapat berkontribusi untuk memberikan informasi dasar bagi para pembuat kebijakan seperti BNPB di Cianjur dalam perencanaan mitigasi longsor.
Kata kunci: longsor, gempa bumi, percepatan tanah maksimum, fault fracture density, Chan-Vese
A JURIDICIDADE E OS PARÂMETROS PARA A APLICAÇÃO DA TEORIA DA FAILING FIRM DEFENSE NO DIREITO CONCORRENCIAL BRASILEIRO
No full textEsta pesquisa examina a compatibilidade da teoria da failing firm defense (FFD) com o direito brasileiro, bem como os critérios a serem utilizados para a sua incorporação ao ordenamento jurídico pátrio. Trata-se de tese desenvolvida inicialmente nos Estados Unidos, mas que se espraiou para o modelo concorrencial de diversas jurisdições, referente à possibilidade de se aprovar um ato de concentração, malgrado produza efeitos anticoncorrenciais, a fim de evitar os malefícios da falência de uma empresa em grave crise econômico-financeira. Assim, inicialmente há o aprofundamento acerca da juridicidade da recepção de referida teoria à luz da regulação antitruste brasileira. Sob essa perspectiva, parte da relevância da FFD nos sistemas concorrenciais norte-americano e europeu. Em seguida, investiga de maneira mais estrita se a legislação antitruste nacional autoriza a recepção da FFD. Ao cabo da primeira parte, cuida dos benefícios e riscos da FFD. Em um segundo momento, discute quais seriam os critérios adequados para aplicar a FFD, levando em consideração o arranjo jurídico-institucional brasileiro. Nesse sentido, examina os requisitos consagrados na legislação norte-americana. Posteriormente, são aprofundadas as peculiaridades da teoria no sistema europeu. Com base nesses sistemas, tenta traçar parâmetros que podem auxiliar na construção de um modelo para o sistema concorrencial brasileiro. Por derradeiro, expõe as conclusões do trabalho relativas à juridicidade ou não da aplicação da FFD no direito concorrencial brasileiro e aos critérios que podem ser utilizados com esse desiderato. Failing Firm Defense. Ato de Concentração. Empresa em Crise
Fixed flexion deformity following total knee arthroplasty. A prospective study of the natural history.
No full textAuthor(s) Pre or Post Print Version OnlyINTRODUCTION: Stiffness following total knee arthroplasty (TKA) is a disabling problem resulting in pain and reduced function. OBJECTIVE: The aim of our study was to evaluate the natural course of fixed flexion deformity (FFD ) following primary total knee arthroplasty. METHODS: Prospective review of 1626 patients undergoing primary TKA from 2001 to 2006 with a minimum of 4 year follow up. Demographic data included post-operative range of motion; type of prosthesis used, treatment modalities for stiffness and the final range of motion were recorded. FFD was defined as class 1(5-15 degrees) and Class 2 (> 15 degrees). Patients with a pre-operative FFD of >15, infection, stiffness treated with manipulation or revision surgery were excluded from the study. RESULTS: Of the 1626 patients evaluated, 170 (10.5%) presented with a FFD. 18 patients were excluded from the study and 16 were lost to follow up. 124 (91.2%) were class 1 and 12 (8.8%) were class 2. FFD improved from a mean of 8.8 degrees to 0.4 degrees (p<0.0001) in 11.4 months. In 94.1% patients the FFD completely resolved (i.e. < 5 degrees) at a mean of 10.8 months (p<0.0001). In the remaining 5.9% of patients, FFD improved from a mean of 16.4 to 6.9 degrees at a mean follow up of 21.5 months (p<0.0001). CONCLUSION: A gradual improvement in the FFD can be expected up to 2 years and a small residual flexion contracture does not cause functional deficit. LEVEL OF EVIDENCE: Prospective cohort study, level 3
Constrained Aerodynamic Shape Optimisation of the Flying V Outer Wing
No full textThe Flying V is a flying wing aircraft consisting of two pressurised passenger cabins placed in a V shape. Its longitudinal and lateral control is ensured via elevons and split flaps on the outboard wing, and rudders on the tip-mounted winglets. The goal of this study is to devise a design for the outboard wing of the Flying V through a constrained aerodynamic shape optimisation at cruise conditions. The design process is divided into a geometry preparation phase in which the existing parametrisation is adjusted, followed by a planform design optimisation guided by the Differential Evolution algorithm making use of a vortex-lattice method and an Euler flow analysis. The cross-sectional shape of the wing is subsequently optimised through a Free-Form Deformation (FFD) shape optimisation based on the Euler equations. Two FFD optimisations are conducted to evaluate the effect of the constraint related to the integration of the elevons. The highest lift-to-drag ratio is obtained by neglecting the elevon integration and amounts to 20.3. Whereas the design constraints imposed by the elevon integration reduce the maximum lift-to-drag ratio to 19.4. The overall efficiency gain compared to the original aircraft design is equivalent to 13% and 8% for the designs, respectively.Flying-VAerospace Engineerin
Constrained Aerodynamic Shape Optimisation of the Flying V Outer Wing
No full textThe Flying V is a flying wing aircraft consisting of two pressurized passenger cabins placed in a V shape. Its longitudinal and lateral control is ensured via elevons and split flaps on the outboard wing, and rudders on the tip-mounted winglets. The goal of this study is to devise a design for the outboard wing of the Flying V through a constrained aerodynamic shape optimization at cruise conditions. The design process is divided into a geometry preparation phase in which the existing parametrization is adjusted, followed by a planform design optimization guided by the Differential Evolution algorithm making use of a vortex-lattice method and an Euler flow analysis. The cross-sectional shape of the wing is subsequently optimized through a Free-Form Deformation (FFD) shape optimization based on the Euler equations. Two FFD optimizations are conducted to evaluate the effect of the integration of the elevons. The highest lift-to-drag ratio is obtained by neglecting the control surface integration and amounts to 20.3. While the constraints related to this elevon integration reduce the efficiency to 19.4. The overall efficiency gain compared to the original aircraft design is equivalent to 13% and 8%, respectively. A further increase is expected once the inefficient outboard wing is optimized in more detail
Effect of chitosan lemon essential oil coatings on storage-keeping quality of strawberry
No full text[EN] Film-forming dispersions (FFD) were prepared with 1% high molecular weight chitosan and 3% lemon essential oil and were submitted to two different homogenization treatments. The particle size and viscosity of the FFD were evaluated and stand-alone coatings were characterized in terms of water vapour permeability (WVP) and antimicrobial activity. The FFD were applied to cold-stored strawberries, cv. Camarosa, and the physicochemical properties, fungal decay and respiration rate of strawberries were determined throughout cold storage at 5 degrees C. The use of microfluidization to prepare chitosan-based FFD led to a significant reduction in the particle size and apparent viscosity of the dispersions, with no significant effect on the decrease in the WVP of the stand-alone coatings. Chitosan coatings did not show a significant effect in terms of the acidity, pH and soluble solid content of strawberries throughout storage. In contrast, coatings slowed down the respiration rate of samples when lemon essential oil was added to the FFD. Adding lemon essential oil enhanced the chitosan antifungal activity both in in vitro tests and during cold storage in strawberries inoculated with a spore suspension of Botrytis cinerea.The authors acknowledge the financial support provided by Conselleria de Empresa, Universidad y Ciencia (project GV/2010/082), Universitat Politecnica de Valencia (project PAID-06-09-2834) and Ministerio de Economia y Competitividad (project AGL2010-20694). Author A. Perdones is grateful to Universitat Politecnia de Valencia for a FPI grant.Perdones Montero, Á.; Sánchez González, L.; Chiralt, A.; Vargas, M. (2012). Effect of chitosan lemon essential oil coatings on storage-keeping quality of strawberry. Postharvest Biology and Technology. 70:32-41. https://doi.org/10.1016/j.postharvbio.2012.04.002S32417
First report of collagenase production by Trichosporon sp. strain isolated from pollen of Amazonian bee (Melipona seminigra seminigra)
No full textTrichosporon yeasts are widely employed to produce lipids, lipases, and aspartic peptidases, but there are no previous studies on collagenase production. This work aimed to select the best collagenase producing Amazonian Trichosporon strains. Moreover, a 2(3)-full factorial design (FFD) and a 2(2)-central composite design combined with Response Surface Methodology were applied to optimize production and find the best conditions for hydrolysis of type I bovine collagen. Most of the studied strains had some collagenolytic activity, but the selected one achieved the highest value (44.02 U) and a biomass concentration of 2.31 g/L. The best collagenase production conditions were 160 rpm of agitation, pH 5.5 and a substrate concentration of 4.0 g/L. The former experimental design showed that substrate concentration was the only statistically significant factor on both biomass concentration and collagenase activity, while the latter showed simultaneous effects of substrate concentration and pH on collagenolytic activity, which peaked at pH 5.5-6.4 and substrate concentration of 3.0-3.4 g/L. An additional 2(3)-FFD was finally used to optimize the conditions collagen hydrolysis, and pH 6, 25 degrees C and a substrate concentration of 7.5 (g/L) ensured the highest hydrolysis degree. This study is the first that describes optimized conditions of collagenase production by Trichosporon strains
The benefits of elective spinal implant removal: a retrospective study of 137 patients
No full textPURPOSE While spinal instrumentations are becoming more common, the advantages of elective spinal implant removal remain ambiguous. We hypothesized that elective implant removal of the posterior spine is beneficial. METHODS A retrospective study evaluated 137 consecutive trauma patients with elective implant removal of the posterior spine. If additional cages were present, they were not removed. Primary outcomes were the change in pre- and post-operative pain, fingertip-floor distance (FFD), and Cobb angles. Some secondary outcomes consisted of complications, work disability, and pelvic incidence (PI). Different stabilization approaches and cage sizes were compared. RESULTS The presence and amount of pain as well as the FFD showed significant improvement. There was no loss of reduction. Delayed wound healing was observed in 9 %, but only 3 % needed revision. Thoracic fascial dehiscences were seen only in patients (9 %) that had stand-alone posterior surgery. Larger cages were associated with increased work disability. An increased PI was associated with less post-operative pain and decreased FFD. CONCLUSIONS In this study, trauma patients benefited from elective implant removal of the posterior spine due to lower presence and level of pain, improved function and low revision rates; irrespective of an initial combined or stand-alone posterior approach or varying cage sizes. However, stand-alone posterior instrumentation may be accompanied by increased rates of fascial dehiscence surgeries and larger cages may lead to increased work disability. Increased PI may be associated with less pain after spinal implant removal
PARAMETRIZATION OF HIGH-SPEED TRAIN STREAMLINE SHAPE
No full text
In the past decade, the high speed trains (HSTs) in China have experienced a booming development, with the design of CRH380A as a predominant example. A series of brand new HSTs have been developed with high aerodynamic performance, which includes the running resistance, the lift of the trailing car, pressure waves when trains pass by each other, aerodynamic noise in the far field, etc. In order to design HSTs with better aerodynamic performance, it is necessary to perform aerodynamic shape optimization, especially to optimize the streamline shape of HSTs. Parametrization is the basis for the whole optimization process, since good parametrization approach not only affects the optimization strategy, but also determines the design space and optimization efficiency. In the present paper, a series of work related to the streamline shape parametrization performed by the author in recent years have been introduced. Four different parametrization approaches have been exhibited, which are Local Shape Function method (LSF) and Free-Foam Deformation method (FFD), Modified Vehicle Modeling Function method (MVMF), Class function/Shape function Transformation method (CST). These methods could be categorized into two kinds: shape disturbance approach (LSF and FFD) and shape description approach (MVMF and CST). Among these four methods, some are developed by the authors while some are locally modified so as to meet the parametrization of the streamline shape. The detailed process of these four approaches are exhibited in the present paper and the characteristics of these four approaches are compared.</p
Parametric optimization of material extrusion 3D printing process: an assessment of Box-Behnken vs. full-factorial experimental approach
No full textThis work investigates the efficiency of the Box-Behnken design (BBD) in contrast with the full-factorial design (FFD) in ultimate tensile strength (UTS) of PA12 material extrusion 3D printing (ME-3DP) specimens. Three input parameters, i.e., the raster angle (A), layer thickness (B), and nozzle temperature (C) with three levels each, were employed to compare the BBD and FFD efficiency. The 81 full-factorial UTS initial experimental data used in this research have been produced in a previous work published by the authors. Fifteen (15) out of 81 experiments were selected for the BBD design with three repetitions on the central point (0,0,0). Main effect plots (MEP), interaction plots, surface plots, ANOVA analysis, normality plots, mean absolute percentage error (MAPE), and the root-mean-square error (RMSE) evaluate the BBD and FFD approaches. The BBD MAPE and RMSE indexes show that the Box-Behnken design is appropriate for parameter analysis and processing investigation resulting in a 5.3% MAPE and 2.75 RMSE, close to 5.2% and 2.44 of the full-factorial MAPE and RMSE indexes. © 2022, The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature
