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1
Ren, Daxin, Fanyu Zeng, Liming Liu, and Kunmin Zhao. "Bending Properties of Mg Alloy Tailored Arc-Heat-Treated Blanks." Materials 12, no. 6 (2019): 977. http://dx.doi.org/10.3390/ma12060977.
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Tailored heat-treated blank is a special kind of sheet, and the plastic forming ability can be improved. In this work, the poor room-temperature plasticity of a tailored magnesium alloy blank was address through arc heat treatment. The formability of the material was enhanced through local modification with arc pretreatment. The plasticity of the tailored arc-heat-treated blank was verified through the V-bending test. The microstructure and mechanical properties of the blank were tested, and the mechanisms underlying its improved deformability were analyzed. The bendability of the blank first increased and then decreased as heat input increased. The maximum V-bending ability of the arc-heat-treated blank increased by 88% relative to that of the untreated blank. Although springback decreased under increasing heat input, the local strength and elastic modulus of the alloy blank were equivalent to those of the base metal. This result indicated that the springback resistance of the material did not improve. The back of the blank treated under the optimal parameters comprised heat-affected zones with good plasticity. Recrystallization and grain growth occurred in the heat-affected zones. The blank exhibited reduced hardness and improved malleability. When the heat input was further increased, however, a semi-melting zone formed on the lower surface of the blank. The formation of this zone resulted in the precipitation of intermetallic compounds from the crystal phase and increased the hardness of the blank. It also decreased the plasticity and malleability of the blank.
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Liu, Pei Xing, Hong Liang Yi, Ya Xu, Yi Lin Wang, and Yi Sheng Zhang. "Localized Austenitizing of the Blank to Make Tailored-Properties by Induction Heating." Advanced Materials Research 1063 (December 2014): 190–93. http://dx.doi.org/10.4028/www.scientific.net/amr.1063.190.
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In this research, a novel hot stamping process to make tailored-properties is proposed. The local areas of blank are heated by induction heating. In the high strength zones, they are heated to austenitizing temperature, and in the absorption zones without heating. The temperature field of transition zone is determined by the thermal conduction between austenitizing temperature and ambient temperature. This novel process can be used for industrialization without changing mold design and stamping process.
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Xing, Zhong Wen, Jun Jia Cui, Hong Sheng Liu, and Chun Feng Li. "Numerical and Experimental Investigation into Hot Stamping of High Strength Steel Sheet for Auto B Pillar Reinforced Panel." Advanced Materials Research 129-131 (August 2010): 322–27. http://dx.doi.org/10.4028/www.scientific.net/amr.129-131.322.
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Hot stamping is an innovative way to manufacture complex-shaped components of high strength steel (HSS) sheet with a minimum of springback, meanwhile, it can also obviously improve the tensile strength of the formed parts.The coupled thermo-mechanical FE model for hot stamping of HSS sheet for the B pillar was established by commercial software Pam-stamp. Dynamic explicit module was used to simulate the forming processes under different process parameters. The effects of process parameters on thinning of the blank were studied, the maximum thinning zones of the blank in hot stamping were analyzed. The results show that the thinning rates of the blank increase when the blank holder force(BHF) and friction coefficient increase, the maximum thinning zones appear at the straight wall and corner of the B pillar. The causal of blank thinning during hot stamping was analyzed. Experiments had been conducted with the process parameters obtained by simulation. The experimental and simulation results were in good agreement.
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Zheng, Zai Xiang, Jing Xu, and Guo Xian Liu. "Research on Friction Behavior in Tube Hydroforming Process." Applied Mechanics and Materials 217-219 (November 2012): 1774–78. http://dx.doi.org/10.4028/www.scientific.net/amm.217-219.1774.
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In the tube hydroforming process, the friction behavior between the tube blank and the die is very complex. As a result, it is very difficult to build a precise friction model in accordance with the actual working conditions by fully taking into account the various factors. In this paper, the friction behaviors between the tube blank and the die in the guided, transition and expansion zones have been studied with the help of numerical simulation and experimental tests. The influences of the different friction conditions in the three zones as well as the uneven friction behavior in the expansion zone on the thickness distribution of tube wall and the characteristics of material flow have been analyzed and experimental tests have been carried out for the verification. The conclusions have provided theoretical references for the process planning, selection of lubrication and tooling design in the actual production process of tube hydroforming.
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Rakhmanov, S. R. "Simulation of vibration piercing of pipe blank at press." Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 76, no. 11 (2020): 1128–38. http://dx.doi.org/10.32339/0135-5910-2020-11-1128-1138.
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In some cases, the processes of piercing or expanding pipe blanks involve the use of high-frequency active vibrations. However, due to insufficient knowledge, these processes are not widely used in the practice of seamless pipes production. In particular, the problems of increasing the efficiency of the processes of piercing or expanding a pipe blank at a piercing press using high-frequency vibrations are being solved without proper research and, as a rule, by experiments. The elaboration of modern technological processes for the production of seamless pipes using high-frequency vibrations is directly related to the choice of rational modes of metal deformation and the prediction resistance indicators of technological tools and the reliability of equipment operation. The creation of a mathematical model of the process of vibrating piercing (expansion) of an axisymmetric pipe blank at a piercing press of a pipe press facility is an actual task. A calculation scheme for the process of piercing a pipe plank has been elaborated. A dependence was obtained characterizing the speed of front of plastic deformation propagation on the speed of penetration of a vibrated axisymmetric mandrel into the pipe workpiece being pierced. The dynamic characteristics of the occurrence of wave phenomena in the metal being pierced under the influence of a vibrated tool have been determined, which significantly complements the previously known ideas about the stress-strain state of the metal in the deformation zone. The deformation fields in the zones of the disturbed region of the deformation zone were established, taking into account the high-frequency vibrations of the technological tool. It has been established that the choice of rational parameters (amplitude-frequency characteristics) of the vibration piercing process of a pipe blank results in significant increase in the efficiency of the process, the durability of the technological tool and the quality of the pierced blanks.
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Rathmann, Lewin, and Frank Vollertsen. "Experimental identification of essential features of micro strip drawing with double deflection." Advanced Technologies & Materials 43, no. 2 (2018): 1–5. http://dx.doi.org/10.24867/atm-2018-2-001.
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In sheet metal forming contact between blank and die edge is reduced to local contact zones. For micro range, they can easily be found during a simulation, but an experimental evidence is difficult. Therefore, an optical projection of strip drawing with double deflection is presented and it is demonstrated that the contact zones can be identified using this method. These results are compared to those from simulation and it is shown that they reflect the simulative results. The results are presented on the basis of using a die with a die radius of r = 0.6 mm. The height of the gap between die edge and blank at the moment of their maximum distance is determined in the experiment to d = 18 ± 9 μm while it is d = 2 μm in the simulation.
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Ghennai, Walid, Ouzine Boussaid, Hocine Bendjama, and Noureddine Guersi. "Pressure and Friction Effects on the Mechanical Behaviour of a Ductile Material during Deep Drawing." International Journal of Engineering Research in Africa 41 (February 2019): 8–19. http://dx.doi.org/10.4028/www.scientific.net/jera.41.8.
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The aim of this work is to study the plastic instabilities occurring on the stamped sheets during deep drawing process. The analysis of the plastic deformation of the material showed that the deformation occurs in bi-axial extension at the bottom of the punch due to thinning of the sheet, in local necking together at the vertical wall level of the sheet and below the blank holder due to thickening of the sheet. As a first step, an experimental characterization of the material is undertaken, whose experimental tests made it possible to determine the fundamental characteristics of the material. In the second step, a study of the material behaviour during forming process by numerical simulation using Abaqus finite element code is proposed. The various simulations undertaken showed the variation of the two parameters; the blank holder force and the friction effect. The blank holder force and friction, applied respectively to the blank flange region and between the tool-blank surfaces, make it possible to optimize the deformation limits and to repel any instability which may appear on the material in deep drawing. The simulations carried out on Abaqus code allow to visualize the material behaviour during deformation, by locating the thinning and necking zones on the sheet and from there, in order to locate areas at risk of failure. An optimization of the process is proposed by varying the considered parameters in a validated numerical model. Satisfactory results have been obtained which clearly show the failure and the safe zones.
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Anishchenko, Aleksandr, Volodymyr Kukhar, Viktor Artiukh, and Arkhipova Olga. "Superplastic forming of shells from sheet blanks with thermally unstable coatings." MATEC Web of Conferences 239 (2018): 06006. http://dx.doi.org/10.1051/matecconf/201823906006.
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The article is devoted to superplastic forming of non-uniformly heated sheet blanks from aluminum alloy AMg6M. To create an uneven temperature field over the surface of the blank, coatings made of sublimated substances were used from at temperatures 50…150°C below the superplastic forming temperature (450°C for AMg6M alloy). An aqueous solute of chloride and ammonium iodide having a sublimation temperature at normal pressure and a latent heat of conversion equal to 338 and 404°C, 330 and 355kJ/kg, respectively, was sprayed onto the central zones of the blanks. Superplastic forming of shells was carried out in two modes: 1) with simultaneous sublimation of the coating; 2) with the beginning of the sublimation of the coating upon reaching the height, which is formed by the workpiece, equal to 20-30% of the final shell height. The experiments showed a decrease in the thickness of the shells to be formed up to 4-10% on the working surface of the shells (without taking into account their flange zones) and the savings of sublimate during superplastic forming in the second mode. The optimal subliming coating for AMg6M alloy was ammonium chloride.
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Rubtsov, V. Yu, O. I. Shevchenko, and M. V. Mironova. "IMPROVING DYNAMIC REGIME OF ROLLING FOR INCREASING DURABILITY OF BALL-ROLLING MILL ROLLS." Izvestiya Visshikh Uchebnykh Zavedenii. Chernaya Metallurgiya = Izvestiya. Ferrous Metallurgy 61, no. 12 (2019): 927–32. http://dx.doi.org/10.17073/0368-0797-2018-12-927-932.
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One of the important reasons for the downtime of ball rolling mills is replacement of rolls due to their wear and tear. The degree and zones of critical wear of ball rolling rolls are investigated in the article, where the greatest wear is observed over the flanges in zone of billet capture. Conditions necessary to capture the blank and to perform rolling process are analytically determined. Variable frequency method of roll rotations is proposed as a progressive technology for blank supply. The results of tests for its variations in accordance with linear and quadratic law are presented. Known formulas determining average strain rate at rolls rotational speed change are converted for linear and quadratic dependences. Experimental studies have been carried out in conditions of EVRAZ Nizhnetagilsky Metallurgical Plant ball rolling mills during rolling of 60mm ball made of Sh-3G steel. Experiments were performed for given parameters of manual change in rolls rotation speed at blank capture by rollers. The results have shown a significant effect of change in rotational speed on average specific pressure during blank capture. Evaluation of torque-time and average contact pressure for calculated and experimental data are presented. Empirical characteristics are also described at variable rotational speed of rolls according to linear and quadratic law. Acceptable convergence of results of calculated and empirical characteristics is determined. Engineering solution has been proposed for that task. It consists in installation of a thyristor converter. This solution allows reduction of rolls speed before blank capture. Also, this solution will increase frequency to the nominal value according to the given law after blank capture. As an obtained result, there is uniform distribution of average contact pressure over the entire length of the roll under different operating conditions of mill in automatic mode. Application of this technique will reduce wear degree of the rolling tool. At the same time, productivity of ball rolling mill will be maintained. Rolls consumption and number of rolls change will decrease due to rolls wear.
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Liu, Cai-yi, Yan Peng, Ling Kong, Lu-han Hao, and Ren Zhai. "Hot forming with a nonuniform temperature field using die partition cooling." Metallurgical Research & Technology 116, no. 6 (2019): 613. http://dx.doi.org/10.1051/metal/2019044.
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High strength steel hot forming technology plays an important role in achieving lightweight vehicles, improving the safety of vehicles. The tensile strength of the blank formed by traditional hot forming process is as high as 1500–2000 MPa, the strength of the formed blank is high, but the elongation is usually low and comprehensive mechanical property is not high. In this article, the process control of material gradient properties hot forming technology is summarized through the analysis of strengthening mechanism of gradient distribution hot forming technology. Based on the traditional hot forming technology, a new hot forming technology based on partition cooling to achieve material property gradient distribution is proposed. By changing the cooling rate of blank in different zones is different, and the gradient distribution of material properties is finally obtained. The DEFORM is used to analyze the hot forming process of the blank under the nonuniform temperature field of the partition cooling. A set of partition cooling hot forming die was designed independently to verify the experimental results. The evolution mechanism of microstructure and its effect on material properties during hot forming under nonuniform temperature field with partition cooling were revealed.
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Mori, Ken-Ichiro, Tomoyoshi Maeno, and Yuzo Yanagita. "Deep Drawability and Bendability in Hot Stamping of Ultra-High Strength Steel Parts." Key Engineering Materials 716 (October 2016): 262–69. http://dx.doi.org/10.4028/www.scientific.net/kem.716.262.
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The deep drawability and bendability in hot stamping of ultra-high strength steel parts were examined. Although the cold drawability is greatly influenced by the blank shape, the limiting drawing depths for the square and circular blanks were equal for hot stamping because of small flow stress. In hot hat-shaped bending using draw-and form-type tools, the effect of the blankholder force generated with the draw-type tools on the springback was small, and the seizure for the form-type tools was smaller than that of the draw-type tools. Since both edges in contact with the electrodes are not heated for resistance heating, cracks were caused at the edges for resistance heating in the transversal directions in hot stamping of an S-rail with form-type tools, and thus it is required to control deformation of the non-heating zones.
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Liu, Philip Lance A., Rose Lou Marie C. Agbay, and Samantha S. Castañeda. "In vitro Antibacterial Activity of Mometasone Furoate, Fluticasone Propionate and Fluticasone Furoate Nasal Preparations Against Streptococcus pneumoniae, Hemophilus influenzae, Streptococcus viridans, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli." Philippine Journal of Otolaryngology-Head and Neck Surgery 25, no. 1 (2010): 13–16. http://dx.doi.org/10.32412/pjohns.v25i1.649.
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Objective: To test the antibacterial properties of three commercially available nasal corticosteroid preparations containing Mometasone Furoate (MF), Fluticasone Propionate (FP) and Fluticasone Furoate (FF) against S. pneumoniae, S. viridans, S. aureus, H. influenza, P. aeruginosa and E. coli.
 Methods:
 
 Study Design: Experimental in vitro study using the disc diffusion method.
 
 Clinical isolates of Streptococcus pneumoniae, Hemophilus influenzae, Streptococcus viridans, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli were inoculated on separate plates. 0.15 ml of nasal corticosteroid preparations containing MF, FP and FF were applied to blank paper discs, then placed on the plates, including an empty disc. Following 24 and 48 hours of incubation, the inhibition zones were measured to the nearest mm from the point of abrupt inhibition of growth.
 Results: After 24 and 48 hours of incubation, S. pneumoniae, S. viridans, and S. aureus showed inhibition zones to all three preparations. S. aureus and S. viridans show the largest zones of inhibition at 24 and 48 hours respectively. H. influenza, P. aeruginosa and E. coli were negative. The inhibition zones of each bacteria were shown to be statistically different. The preparation containing FP had the largest zone of inhibition at 24 and 48 hours, although post hoc tests showed their difference was not significant.
 Conclusion: The present study demonstrates possible antimicrobial properties of commercially-available nasal corticosteroid preparations. However, it is unclear whether these can be attributed to the steroids, their excipients, or both. Further studies testing each component may offer better insights into their therapeutic use.
 Keywords: Mometasone Furoate, Fluticasone Propionate, Fluticasone Furoate, Antibacterial, Nasal Corticosteroids, Allergic Rhinitis, Acute Bacterial Rhinosinusitis
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Luo, Rui-qiong, Fang Wei, Shu-shi Huang та ін. "Real-Time, Label-Free Detection of Local Exocytosis Outside Pancreatic β Cells Using Laser Tweezers Raman Spectroscopy". Applied Spectroscopy 71, № 3 (2016): 422–31. http://dx.doi.org/10.1177/0003702816670911.
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The examination of insulin (Ins) exocytosis at the single-cell level by conventional methods, such as electrophysiological approaches, total internal reflection imaging, and two-photon imaging technology, often requires an invasive microelectrode puncture or label. In this study, high concentrations of glucose and potassium chloride were used to stimulate β cell Ins exocytosis, while low concentrations of glucose and calcium channel blockers served as the blank and negative control, respectively. Laser tweezers Raman spectroscopy (LTRS) was used to capture the possible Raman scattering signal from a local zone outside of the cell edge. The results show that the frequencies of the strong signals from the local zones outside the cellular edge in the stimulated groups are greater than those of the control. The Raman spectra from the cellular edge, Ins and cell membrane were compared. Thus, local Ins exocytosis activity outside pancreatic β cells might be observed indirectly using LTRS, a non-invasive optical method.
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Wagner, Bernd. "Kontaktzonen im Museum. Kindergruppen in der Ausstellung Indianer Nordamerikas." Paragrana 19, no. 2 (2010): 192–203. http://dx.doi.org/10.1524/para.2010.0033.
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AbstractEuropean ethnological museums usually administer not only exhibitions but also large archives. Visitors of the exhibitions generally do not get to know that the archived objects exist. As these objects are omitted and difficult to access they leave a blank position as Deborah Poole remarks. Decisions as to why objects are displayed or archived are an important matter in museum studies. James Clifford is challenging museums to integrate contact zones in their exhibitions. Ethnological museums contribute to intercultural encounter by allowing contact to their archives, opening exhibition spaces for performative play of children and reflecting collections and collectors in terms of postcolonial theory.
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Millo, Grazielle, Apa Juntavee, Ariya Ratanathongkam, Natsajee Nualkaew, Peerapattana, Jomjai, and Supaporn Chatchiwiwattana. "Antibacterial Inhibitory Effects of Punica Granatum Gel on Cariogenic Bacteria: An in vitro Study." International Journal of Clinical Pediatric Dentistry 10, no. 2 (2017): 152–57. http://dx.doi.org/10.5005/jp-journals-10005-1426.
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ABSTRACT Aim This study evaluated the in vitro antibacterial effects of the formulated Punica granatum (PG) gel against Streptococcus mutans, Streptococcus sanguinis, and Lactobacillus casei. Materials and methods The PG extract was dissolved in water at 500 mg/mL. High performance liquid chromatography (HPLC) was used for identification and quantification of chemical marker punicalagin. Minimum bactericidal concentration (MBC) and time-kill assay (TKA) were investigated. Antibacterial activities of the formulated PG gel, 2% chlorhexidine (CHX) gel and blank gel were tested by measuring the zones of inhibition through agar well diffusion method. Results The HPLC results showed presence of punicalagin at 2023.58 ± 25.29 μg/mL in the aqueous PG extract and at 0.234% (w/w) in the formulated PG gel. The MBC for S. mutans, S. Sanguinis, and L. casei were 250, 125, and 500 mg/mL respectively. The TKA of 500 mg/mL aqueous PG extract showed total inhibition of S. mutans, S. Sanguinis, and L. casei at 6, 1, and 24 hours contact time respectively. Agar well diffusion revealed that for S. mutans, CHX gel > PG gel > blank gel; for S. sanguinis, CHX gel = PG gel > blank gel; for L. casei, CHX gel > PG gel = blank gel. Comparison of the PG gel potency showed that S. sanguinis = S. mutans > L. casei. Conclusion The PG gel equivalent to 0.234% punicalagin (w/w) inhibited S. mutans and S. sanguinis but not L. casei within 24 hours incubation period and has the potential to be used for caries prevention. How to cite this article Millo G, Juntavee A, Ratanathongkam A, Nualkaew N, Peerapattana J, Chatchiwiwattana S. Antibacterial Inhibitory Effects of Punica Granatum Gel on Cariogenic Bacteria: An in vitro Study. Int J Clin Pediatr Dent 2017;10(2):152-157.
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Merklein, Marion, and Uwe Vogt. "Enhanced Formability of Ultrafine-Grained Aluminum Blanks by Local Heat Treatments." Key Engineering Materials 410-411 (March 2009): 169–76. http://dx.doi.org/10.4028/www.scientific.net/kem.410-411.169.
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High strength aluminum blanks can be obtained by grain-refinement due to an Accumulativ Roll Bonding (ARB) process, in which two sheets are iteratively brushed, stacked on top of each other and subsequently rolled together. The high shear stresses during the rolling cycles result in an ultrafine-grained microstructure with an average grain size ranging between 200 to 1000 nm. Whereas the grain-refinement causes a drastically increased strength of the aluminum material, the formability of the ARB-blanks made of industrially used aluminum alloys such as the AA6016 deteriorates to the same degree as the strength rises. In this context, a local heat treatment of the ARB-blank reducing the material’s strength and increasing its ductility in specific zones will allow to recover the blank’s formability again. The research work presented in this paper studies the microstructural effects of a short-term heat treatment on the mechanical properties of ARB-blanks made of AA6016. Experimental investigations including hardness measurements, tensile tests as well as microscopic analyses show that heat treatments of only several seconds already result in significant increases of the material’s ductility and decreases of the material’s strength. By applying these microstructural mechanisms in terms of a specific heat treatment layout, functional gradients of strength and ductility adapted to the succeeding forming operation can be setup significantly enhancing the ARB-blank’s formability.
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Patterson, Jan E., M. L. McElmeel, and Nathan P. Wiederhold. "In vitro Susceptibility Testing of Essential Oils against Gram-positive and Gram-negative Clinical Isolates, including Carbapenem-resistant Enterobacteriaceae (CRE)." Open Forum Infectious Diseases 4, suppl_1 (2017): S370. http://dx.doi.org/10.1093/ofid/ofx163.907.
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Abstract Background In the era of antibiotic resistance, alternative anti-infectives must be explored. The National Action Plan for Combating Antibiotic-Resistant Bacteria calls for developing nontraditional therapeutics, including natural compounds such as essential oils (EOs) (Goal 4.4). A pilot study previously showed in vitro activity of EOs against CRE and warranted further study of their antibacterial activity. We studied cinnamon bark, clove, lavender, lemongrass, eucalyptus, oregano, rosemary, thyme, tea tree, manuka, and Thieves® blend (Young Living Essential Oils, Lehi UT) against an expanded panel of Gram-positive and Gram-negative isolates. Methods 30 Gram-positive and 70 Gram-negative clinical isolates, including CRE, were tested using CLSI methods. Isolates were grown overnight on TSA; 0.5 McFarland suspensions in sterile water were swabbed over Mueller–Hinton agar using the Kirby–Bauer method. 20 μl of full-strength oils were pipetted onto blank paper disks in a sterile dish. Disks were placed aseptically onto the plates immediately after inoculating disks. Vancomycin was tested with Gram-positives and meropenem with Gram-negatives. Median zone diameters are shown. Results EOs oregano, thyme, cinnamon bark, and lemongrass had the largest zones of inhibition against Gram-positive organisms and were larger than those of vancomycin for MRSA/MSSA. Cinnamon bark had the largest zone of inhibition against P. aeruginosa and was larger than that of meropenem. Oregano, thyme, cinnamon bark had the largest zones of inhibition against Enterobacteriaceae and were larger than those of meropenem against K. pneumoniae and E. cloacae. Conclusion Essential oils showed significant in vitro activity against clinical isolates, including CRE. Further study of the clinical activity of essential oils is warranted. Disclosures J. E. Patterson, Young Living Essential Oils: Independent Contractor, Salary
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Phanitwong, Wiriyakorn, Juksawat Sriborwornmongkol, and Sutasn Thipprakmas. "Zoning Lubricant Die Application for Improving Formability of Box-Shaped Deep Drawn Parts." Metals 11, no. 7 (2021): 1015. http://dx.doi.org/10.3390/met11071015.
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The ‘formability’ of sheet metal is a major keyword referring to process design in the sheet metal forming industry. Higher formability could reflect lower production costs and time. Many studies have been carried out to improve formability in various ways, by using the finite element method and experimental approaches. In the present research, a new zoning lubricant technique is proposed. The stainless steel SUS304 square deep drawn box is used as an investigative model. Based on the material flow analysis, we found that zoning lubricant die application could reduce the difference in material flow velocity between wall and corner zones. This material flow characteristic resulted in decreased nonconcurrent plastic deformation during the deep drawing process, as well as decreased stretching in the cup wall and the delaying of the fracture. In the present research, the design of the zoning lubricant die was strictly concerned with achieving functionality related to the friction coefficient, area of zoning, and blank-holder pressure. A smaller friction coefficient positioned in the corner zone and larger friction coefficient positioned in the wall zone are recommended. It was revealed that, by appropriate zoning lubricant die application, formability could be increased in terms of box height by approximately 7 mm or 10%.
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Albut, Aurelian. "Investigation Concerning Maximal Forming Depth of Tailor Welded Blanks Made from same Material but Different Thickness Ratios." Applied Mechanics and Materials 371 (August 2013): 275–79. http://dx.doi.org/10.4028/www.scientific.net/amm.371.275.
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The formability of tailor welded blanks is significantly reduced compared with the homogeneous blanks. Some of the important factors that are behind this fact are: material property changes in the weld and the heat-affected zones, non-uniform deformation because of the differences in thickness, properties and/or surface characteristics and location and orientation of the weld with respect to the direction of application of load. The objective of this resarch work is to establish a relation between thickness ratio and maximal forming depth in TWBs made from same material but having different thickness. For the numerical simulation it was considered a rectangular workpiece with dimensions: 147,8mm x 147,8mm. Depending on the thickness value of the blank, the design of the working tools must be modified the dimensions of the punch using the same die for all simulations. During the simulation the FLD predict de forming behaviour of the metal sheet. For this study there was not a statistically significant relationship between maximal forming depth and thickness ratio of the tailor welded blanks. But it was possible to generate fitted models, that are parabolic relations, starting with the maximal forming depth for ratio 1 (homogeneous sheet), when the ratio increases, firstly the maximal forming depth decreases until one point where the tendency changes and lately increases, and the maximal forming depth achieves values even higher than the initials. Also it can be said that the thicker is the thin sheet the closer is the parabolic fitted form.
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Ghazali, Tengku Muhammad, Rahman Karnila, and Dewita Dewita. "CHARACTERISTICS AND EFFECTIVENESS OF CHITOSAN ORININATED FROM THE CARAPACE OF T. ANOMALA SHRIMP AS AN ANTIBACTERIAL COMPOUND." Berkala Perikanan Terubuk 47, no. 1 (2019): 93. http://dx.doi.org/10.31258/terubuk.47.1.93-101.
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This study aims to investigate the inhibition zones of the chitosan against Pseudomonas aeruginosa. Carapace from T. anomala is used as raw material of chitosan. There were 5 treatments used, namely positive control (K0+), negative control (K0-), 5% chitosan (K1), 7% chitosan (K2) and 9% (K3) chitosan. The carapace was taken and then washed, dried, refined, demineralization, de-preoteinated, deasitelation and was tested using double layer method, discs and well diffusion. The proximate carapace test results were as follows, water content was 68.18 % gross wight (gw), moisture content 11.77 % dry wight (dw) protein content, 2.35 %dw fat content, 84.43 %dw ash content and carbohydrate content was 1.45 %dw. The chitosan of T. anomala characteristics were yellowish white flakes, odorless and tasteless with yield value, moisture content, ash content, mineral content (Ca, Fe, K, Na, P) and the degree of deacetylation 27.51 %; 7.31 %gw; 3.40 %dw; 12.17 mg/L; 4.90 mg/L; 3.40 mg/L; 5.49 mg/L; 0.27 mg/L; and 73.43 % respectively , Results on antimicrobial sensivity tests using double layer, disk blank and well diffusion. Shown clear zone, 13.87 mm, 11.34 mm and 14.62 mm. these values indicate that the antimicrobial effect of the chitosan is strong.
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Gasparik, M., Y. Gensterblum, A. Ghanizadeh, P. Weniger, and B. M. Krooss. "High-Pressure/High-Temperature Methane-Sorption Measurements on Carbonaceous Shales by the Manometric Method: Experimental and Data-Evaluation Considerations for Improved Accuracy." SPE Journal 20, no. 04 (2015): 790–809. http://dx.doi.org/10.2118/174543-pa.
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Summary In exploration for shale gas, experimental methane-sorption measurements represent a valuable source of information for resource estimates and for reservoir-modeling studies. Here, the main difficulty is the relatively low adsorption capacity of shales (typically 10% of the sorption capacity of coals), as well as the fact that the measurements need to be performed over a wide range of pressures and temperatures characteristic of past or present geological conditions. In this work, we demonstrate the capabilities of an adapted manometric apparatus to reliably measure excess sorption isotherms at pressures of up to 30 MPa and temperatures up to 423 K on carbonaceous shales. This is accomplished with an experimental design comprising separate heating zones for the sample cell and for the rest of the apparatus. An experimental and mass-balance approach is presented to quantify the temperature gradient existing between the two heating zones, as well as the thermal expansion of the sample cell, and to account for these in the calculation of the excess sorption. We demonstrate that the analysis of the helium-void-volume data over a large temperature range can be interpreted with respect to the thermal expansion of the sample and, in some cases, changes in pore-volume accessibility to helium. We propose to perform blank-expansion tests with non-adsorbing specimens (e.g., steel cylinders) as a quality check to eliminate device-specific artifacts resulting from unknown measurement uncertainties or from uncertainty in the equation of state. Two evaluation procedures are presented to quantitatively account for the blank tests in the final result of sorption measurements on shale samples. As an example, methane-sorption isotherms for carbonaceous shale at 311, 338, 373, and 423 K are presented. By use of a Monte Carlo algorithm to simulate the propagation of the experimental uncertainties, the final estimated uncertainty in excess sorption resulting from systematic errors was found to be ± 0.007 mmol/g at 25 MPa. The consideration of the blank-expansion tests in the mass balance further reduces the systematic error, at least to a point at which an excellent intralaboratory consistency is obtained. The estimated uncertainty resulting from random errors was found to significantly overestimate the actual precision of the experimental setup, and an explanation is provided with respect to experimental design. A data-reduction approach using an excess-sorption function based on a Langmuir-type absolute-sorption model was found to provide an excellent representation of the measured sorption data. By means of simplified model calculations we demonstrate that the excess-sorption formalism is a sufficient, simple, and adequate approach to applications in shale-gas-resource estimation. The uncertainties pertaining to representativeness of experimental sorption data of in-situ reservoir conditions are briefly discussed.
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Eaton, David W., Gerald M. Ross, Frederick A. Cook, and A. VanderVelden. "Seismic imaging of the upper mantle beneath the Rocky Mountain foreland, southwestern Alberta." Canadian Journal of Earth Sciences 37, no. 11 (2000): 1493–507. http://dx.doi.org/10.1139/e00-068.
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The Vibroseis Augmented Listen Time (VAuLT) experiment is a special seismic-reflection survey designed to image the fine-scale structure of the continental upper mantle of the Rocky Mountain foreland in southwestern Alberta to depths of 200 km or more. Two mutually perpendicular profiles were acquired across and within the Vulcan structure, a roughly east-west-trending tectonic belt in the crystalline basement beneath the Western Canada Sedimentary Basin that separates the Medicine Hat block from the Loverna block. Relative-amplitude-preserving processing procedures were developed to estimate the seismic-signal-penetration limit, which varies between 100 and 220 km depth. Amplitude-decay analysis and Q estimation show that a seismically unreflective zone within the Vulcan structure is not caused by inadequate signal penetration. This blank zone is interpreted as part of an intrusive complex that has overprinted the preexisting structural fabric. Unlike most other parts of Alberta, the reflection Moho is indistinct and the uppermost mantle (4560 km depth) is reflective, particularly for sourcereceiver offsets >10 km. South-dipping reflectivity in the lower crust and upper mantle beneath the Loverna block and northern Vulcan structure gives way to subhorizontal reflectivity beneath the Medicine Hat block. We interpret this reflectivity as compositional layering and (or) zones of ductile deformation that were previously part of the mafic lower crust, but that have now undergone metamorphic transformation to eclogite. The deepest observed reflection is an isolated, gently north-dipping event at ~120 km depth.
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Springe, M. J., C. R. Hann, and D. H. Johnson. "Quantitative Evaluation of a Standard for Immunogold Labeling of Collagen Type IV." Microscopy and Microanalysis 3, S2 (1997): 349–50. http://dx.doi.org/10.1017/s1431927600008631.
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Quantitative gold labeling studies allow the comparison of tissue antigens only if labeling conditions are the same. When labeling conditions deviate slightly, the labeling efficiency can also shift. Labeling efficiency can be determined on a standard containing known concentrations of the target antigen. When labeling this standard, the labeling density (LD) divided by the antigen concentration (C) gives the labeling efficiency (LE).(l) If the assumption is accepted that labeling efficiency is the same over the standard and tissue, then the antigen concentration in the tissue can be calculated from the labeling density. In this study, a labeling standard was constructed that contained collagen type IV in five concentrations and a blank agarose gel. Our design criteria specified that these six gels measure less than 2 mm across and the zones between protein concentrations be clearly delineated.The labeling standard was constructed by diluting lyophilyzed collagen type IV in water to final concentrations of 1,2,3,4, and 5 mg/ml.
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Khalil, Ahmed M., Reham A. Abdel-Monem, Osama M. Darwesh, Ahmed I. Hashim, Afaf A. Nada, and Samira T. Rabie. "Synthesis, Characterization, and Evaluation of Antimicrobial Activities of Chitosan and Carboxymethyl Chitosan Schiff-Base/Silver Nanoparticles." Journal of Chemistry 2017 (2017): 1–11. http://dx.doi.org/10.1155/2017/1434320.
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Schiff-bases of chitosan (CS) and carboxymethyl chitosan (CMCS)/silver nanoparticles (AgNPs) have been synthesized, characterized, and evaluated as antimicrobial agents against two Gram +ve bacteria (Bacillus cereus and Staphylococcus aureus) and two Gram −ve bacteria (Escherichia coli and Pseudomonas aeruginosa) in addition to Candida albicans as a fungus. The in situ reactions of CS and/or CMCS with some pyrazole aldehyde derivatives in acidic media containing silver nitrate to yield silver nanoparticles loaded onto CS and CMCS/Schiff-bases were carried out. Characterizations of the prepared compounds via FTIR spectroscopy, SEM, TEM, and TGA were carried out. Schiff-bases/silver nanoparticles of CS and CMCS showed higher antimicrobial activity than the blank CS and CMCS. The presence of AgNO3 (3% wt%) displayed high antibacterial efficiencies with inhibition zones in the extent of 19–39 mm. TEM analysis showed that the size of the silver nanoparticles is in the range of 4–28 nm for the prepared nanocomposites.
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Mironenko, Vladimir V., Agnia A. Cheslavskaya, and Sergei V. Belykh. "SIMULATION OF STRETCH-FORMING OF AIRBORNE VEHICLE’ SKIN WITH REGARD TO THE EFFECTS ARISING IN THE ZONES OF THE WORKPIECE BLANK CLAMPING BY JAWS." Scholarly Notes of Komsomolsk-na-Amure State Technical University 1, no. 18 (2014): 13–18. http://dx.doi.org/10.17084/2014.ii-1(18).2.
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Chan, L. C., C. H. Cheng, S. M. Chan, T. C. Lee, and C. L. Chow. "Formability Analysis of Tailor-Welded Blanks of Different Thickness Ratios." Journal of Manufacturing Science and Engineering 127, no. 4 (2005): 743–51. http://dx.doi.org/10.1115/1.2034518.
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This paper presents a formability analysis of tailor-welded blanks (TWBs) made of cold rolled steel sheets with varying thicknesses. Steel sheets ranging between 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, and 1.0 mm in thickness were used to produce TWBs of different thickness combinations. The primary objective of this paper is to characterize the effects of thickness ratios on the forming limit diagram (FLD) for a particular type of TWB. The TWBs chosen for the investigation are designed with the weld line located in the center of the specimens perpendicular to the principal strain direction. Nd:YAG laser butt-welding was used to prepare different tailor-made blank specimens for uniaxial tensile tests and Swift tests. The experimental results of the uniaxial tensile test clearly revealed that there were no significant differences between the tensile strengths of TWBs and those of the base metals. After the Swift tests, the formability of TWBs was analyzed in terms of two measures: The forming limit diagram and minimum major strain. The experimental findings indicated that the higher the thickness ratio, the lower the level of the forming limit curve (FLC) and the lower the formability of the TWBs. The findings also show an inverse proportional relationship between thickness ratios and minimum major strains. TWBs with a thickness ratio of close to 1 were found to have a minimum major strain closer to those of base metals. The effects of different thickness ratios on TWBs were further analyzed with a finite element code in a computer-aided engineering package, PAM-STAMP, while the failure criteria of the TWBs in the finite element analysis were addressed by the FLCs which were obtained from the experiments. However, the weld of the TWB in the simulation was simply treated as a thickness step, whereas its heat affected zones were sometimes disregarded, so that the effects of the thickness ratio could be significantly disclosed without the presence of weld zones. The results of the simulation should certainly assist to clarify and explain the effects of different thickness ratios on TWBs.
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Keller, I. E., A. V. Kazantsev, A. A. Adamov, and D. S. Petukhov. "SIMULATION OF MULTI-STAGE COLD FORMING OF A THIN-WALLED VESSEL." Problems of strenght and plasticity 82, no. 1 (2020): 75–88. http://dx.doi.org/10.32326/1814-9146-2020-82-1-75-88.
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The method of construction and attestation of a numerical model of cold stamping of thin-walled products made of anisotropic metal sheet for the design of technological operations is proposed. The relations of the associated law of plastic flow with the Barlat flow function and isotropic strain hardening are used. The method of design and processing the experiment is proposed for their identification. The forming limit curve is approximated numerically by the Marciniak - Kuczynўski method, and for its identification it is proposed to use a failure test under uniaxial tension and press equipment as an experimental. To do this, a coordinate grid is applied to a flat blank by laser engraving, whose distortions near the zones of strain localization and failure of the vessel give additional points of the forming limit curve. The constants of the Peng - Landel potential are found to describe the elasticity of a polyurethane die under large deformations using tests for free and constrained compression. All tests according to the method were performed for low-carbon sheet steel DC04EK 0.7 mm and SKU-PFL polyurethane. A numerical model of the process in the LS-DYNA package is designed using material models from its library. The calculations according to the model were confirmed by experiment, for which the main deformations were determined by the distorted coordinate grid on the workpiece after each operation at the control points. The calculation of the sequence of stages of stamping, drawing and bulging of the workpiece in the production of the vessel with and without intermediate annealing is performed and the dangerous zones and mechanisms of their formation are determined.
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Wu, Xiaochuan, Renhai Pu, Gongcheng Zhang, Xiaowei Fan, Dong Deng, and Bin Li. "Seismic interpretation of the diapiric structures and gas chimneys in the Liwan gas field, Pearl River Mouth Basin, northern South China Sea." Interpretation 6, no. 3 (2018): T499—T519. http://dx.doi.org/10.1190/int-2017-0129.1.
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Voluminous diapiric intrusions are present in 3D seismic data from the Liwan gas field area in the Baiyun sag of the Pearl River Mouth Basin, South China Sea. These diapirs are subdivided into magmatic diapirs and mud diapirs according to their seismic signatures and formation mechanisms. Saucer- and mound-shaped reflectors with anomalously high amplitudes distributed throughout the Early Miocene strata are interpreted as sills and laccoliths and are typified as magmatic diapirs. Mud diapirs in the study area can be divided into two types: wavy reflectors occurring at the basement of the sag caused by the gravitational instability of plastically deformed mudstones and columnar upheaval anomalies rooted in Paleogene rift sequences. Gas chimneys are characterized by vertical weak/blank zones accompanied by pull-down effects. Vertical gas chimneys and mud diapirs pierce the Middle Miocene strata. The vast majority of them are triggered by normal faulting; however, no deep-seated faults can be detected around the peripheries of igneous intrusions. Migration forces and pathways are represented by vertical mud diapirs and gas chimneys and thus control the distribution of shallow gases with negative-amplitude anomalies as well as gas hydrates.
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Yang, Kun, Hualong Xie, Cong Sun, Xiaofei Zhao, and Fei Li. "Influence of Vanadium on the Microstructure of IN718 Alloy by Laser Cladding." Materials 12, no. 23 (2019): 3839. http://dx.doi.org/10.3390/ma12233839.
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A deleterious Laves phase forms in the solidified structure of Inconel 718 (IN718) alloy during laser cladding. However, effective removal methods have not yet been identified. In this study, we first added the IN718 alloy cladding layers with a trace amount of vanadium (V, 0.066 wt.%). Then, we studied the solidification structure of cladding layers using a confocal laser scanning microscope and scanning electron microscopy. The microstructure and Laves phase morphology were investigated. The distribution of niobium (Nb) was observed by experiment as well. We found that V is evenly distributed in dendrites and interdendritic zones. A more refined dendrite structure, reduced second dendrite arm spacing and lower volume fraction of Laves phase were observed in the solidification structure. The results of linear energy-dispersive X-ray spectroscopy (EDS) indicate that the concentration of Nb decreases with an increasing of the distance from the Laves phase. The V-containing sample displayed a relatively slower decreasing tendency. The IN718 alloy sample was harder with the addition of V. In addition, the porosity of the sample decreased compared with the blank sample. The presented findings outline a new method to inhibit the Nb segregation in IN718 alloy during laser cladding, providing reference significance for improving the performance of IN718 alloy samples during actual processing.
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Nurjanah, Siti, Akhmad Rokiban, and Erdy Irawan. "Ekstrak Umbi Rumput Teki (Cyperus Rotundus) Sebagai Antibakteri Terhadap Staphylococcus Epidermidis Dan Propionibacterium Acnes." Biosfer: Jurnal Tadris Biologi 9, no. 2 (2018): 165–75. http://dx.doi.org/10.24042/biosfer.v9i2.3800.
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The tuber of cyperus rotundus are used to tradisional medicine. C. rotundus known to contain compounds of secondary metabolites such as alkoloids, sineol, pinene, siperon, rotunal, siperenon, siperol, tannins, flavonoids and scientifically it has been believed to have antimicrobial activity. Empirically this plant are used as an antibacterial, antitumor, anticancer, and antiallergic. The purpose of this study were determining the inhibition of extract of Cyperus rotundus against tubers of Staphylococcus epidermidis and Propionibacterium acnes. In this study C. rotundus extracted by maceration using 70% ethanol. The extracts tested against S. epidermidis and P. acnes using disc blank method. The results obtained from the mean diameter of the inhibition zones of exstract at concentrations of 20%, 40%, 60%, 80%, and 100% on S. Epidermidis 8.03 mm, 11.43 mm, 15.04 mm, 15.83 mm and 19.98 mm respectively and P. acnes 11.59 mm, 13.35 mm, 17.17 mm, 20.44 mm, and 30.08 mm respectively Aquades used as negative control and erythromycin used as positive control. Testing were continued by determining the Minimum Inhibitory Concentration (MIC). The result of MIC for S. epidermidis was 15% and P. acnes was 11%. The analysis showed that the antibacterial activity of the tubers extract is bacteriostatic for S. epdermidis and bacterisid for P. acnes.
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Krux, Rainer, Werner Homberg, M. Kalveram, Michael Trompeter, Matthias Kleiner, and Klaus Weinert. "Die Surface Structures and Hydrostatic Pressure System for the Material Flow Control in High-Pressure Sheet Metal Forming." Advanced Materials Research 6-8 (May 2005): 385–92. http://dx.doi.org/10.4028/www.scientific.net/amr.6-8.385.
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A promising approach to control the material flow within deep drawing and workingmedia based forming processes is the structuring of the tool surfaces in the contact zones between workpiece and die. In order to obtain a sufficient and an optimised material flow respectively – especially for non-symmetric or non-uniform workpiece geometries – a locally adapted distribution of surface structures is a practicable solution. The macroscopic, and also the microscopic surface structures can be manufactured sufficiently by means of a high-speed cutting process. The shape of the tool surface structure has a significant influence on the tribological conditions between workpiece and die. To adjust the surface structure distribution to the required material flow distribution, detailed knowledge about the correlation of the material flow from the tribological conditions between sheet and the forming tool is required. A further innovative approach, particularly for decreasing the friction coefficient, is the use of an innovative hydrostatic pressure system using fluid ducts. Its functional principle is based on the reduction of the contact shear stress at the sheet surface in the contact zone with the forming tool by means of locally applying a hydrostatic fluid pressure. To obtain information about the correlation of the material flow from the tool surface structures and from the parameters of the hydrostatic pressure system respectively, fundamental investigations have been carried out. In order to optimise the material flow, these toolbased approaches can be used as stand-alone solution, or in addition to other systems. If the surface structures and a hydrostatic pressure system are used in combination with the multi-point blank holder, which has already been qualified for the high-pressure sheet metal forming (HBU), a powerful system for the material flow control is available.
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Veldi, Martti, and Simon Bell. "A landscape of lies: Soviet maps in Estonia." SHS Web of Conferences 63 (2019): 08002. http://dx.doi.org/10.1051/shsconf/20196308002.
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Maps have long been used as ways of understanding the land as a means of defining borders, land ownership, resources, estimating tax-gathering potential and for defensive purposes. Many of the national mapping agencies originated as arms of the military. When a new regime takes over a country it may decide to prepare its own set of maps – not least for defensive purposes – and to restrict who has access to these maps. When the Soviet Union occupied the Baltic States in 1945 – and these became front-line areas during the Cold War, with large areas devoted to military installations and border zones – a whole new set of maps were created. We took a sample of maps of Estonia from the inter-war years and from the period of political and military occupation from 1945-1991. The Soviet army maps became freely available in the post-Soviet period and studying them and comparing them with the older maps reveals the way the land was perceived. Military maps were produced using different projections and scales, especially regarding the topography and other features relevant for military operations. The maps included deliberate mistakes and if publicly available they contained many blank spaces to hide sensitive areas and to pretend they did not exist. We also found that maps played a key role in planning future landscapes – kolkhoz maps showed how Estonia was foreseen as a complete planned system covering the whole country outside urban areas.
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Qing, Yun, Qian Ma, Ran Li, Xia Shen, XuJin Zhang, and LinFeng Han. "Influence of Channel Regulating Structures on the Transportation and Dissipation of Supersaturated Total Dissolved Gas." Advances in Civil Engineering 2021 (January 22, 2021): 1–8. http://dx.doi.org/10.1155/2021/6634972.
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Bubble dissolution during the flood discharge creates high total dissolved gas (TDG) concentration zones downstream of the dams. The dissipation of supersaturated TDG is a very slow process. Thus, the elevated TDG may remain through the water body for hundreds of kilometers downstream and lead to gas bubble disease (GBD) and even mortality in fish. To improve the navigation conditions of waterways, dikes (i.e., a solid structure) of varied sizes and shapes are commonly constructed. However, this would affect the dissipation and transportation of the supersaturated TDG. It would significantly change the turbulence intensity and hydropressure of the flow, which dominates the dissipation of TDG. Therefore, TDG distribution in the waterway differs from that in the natural river. In this study, a numerical simulation of the TDG at the Yangtze River’s upper reaches (one of the inland waterways in China) was conducted with the establishment of a two-dimensional TDG dissipation model. The effect of the dikes’ size and shape was analyzed to assess the influence of the regulation structures on the dissipation and transportation of the supersaturated TDG. Meanwhile, simulation in the study area with the natural topography was also set as blank control. Based on that, impact evaluation of TDG supersaturation on fish under different simulation scenarios was made. This study can provide a scientific basis for reducing the adverse effect of supersaturated TDG in fish and the construction of ecological waterway therefore.
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Stitt, James H., and Wendy Metcalf Straatmann. "Trilobites from the upper part of the Deadwood Formation (Upper Franconian and Trempealeauan stages, Upper Cambrian), Black Hills, South Dakota." Journal of Paleontology 71, no. 1 (1997): 86–102. http://dx.doi.org/10.1017/s0022336000038981.
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Trilobites assigned to 29 genera and 39 species are reported from the Deadwood Formation in the Black Hills of South Dakota. Two new species, Prosaukia lochmani and Arcifimbria pahasapaensis, are described. Brachiopods are reported from the Taenicephalus Zone.A biostratigraphic zonation is established for the upper part of the Deadwood Formation. The Taenicephalus Zone in the lower part of the study interval is succeeded upsection by the Ellipsocephaloides Zone, both of which are assigned to the Franconian Stage. These two zones are overlain in turn by the Illaenurus and Saukia Zones of the Trempealeauan Stage. These zones are used to correlate this part of the Deadwood with coeval strata in Montana and Wyoming, central Texas, Oklahoma, and Alberta, Canada. The lowstand of sea level that occurred in the Great Basin at the time of the deposition of the Saukiella junia Subzone of the Saukia Zone probably extended eastward into the Black Hills, resulting in the absence of this fauna in the Black Hills.
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Stankova, Svetla, Tzanko Tzankov, and Rosen Iliev. "The West Black Sea passive continental margin in the east part of Balkan Peninsula." Acta Scientifica Naturalis 5, no. 1 (2018): 102–7. http://dx.doi.org/10.2478/asn-2018-0014.
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Abstract The Black Sea Neozoic passive continental margin marks the natural „bridge” between the Moesian and Bulgarian continental microplates and the Black Sea oceanic microplatte. It was coming in to being after the saturation between the terrains which are composed the Neo Europe south east part during the Early Paleogene. The subaerial part of the margin includes the most east parts of the South Moesian, Hemus, and Upper Thracian and Sakar-Strandzha morphostructural zones. The subaquatic part of the margin is composed by the consequently orderly step lower to the Black Sea bottom: high shelf zone, lover shelf zone, continental slope and continental foot. The Black Sea Neozoic passive continental margin is characterized by low seismic activity. It is concentrated in some fault zones.
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Wang, Meng-Jiao, and Yakov Kutsovsky. "Effect of Fillers on Wet Skid Resistance of Tires. Part II: Experimental Observations on Effect of Filler-Elastomer Interactions on Water Lubrication." Rubber Chemistry and Technology 81, no. 4 (2008): 576–99. http://dx.doi.org/10.5254/1.3548221.
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Abstract It was demonstrated previously that on the worn surface of vulcanizates during wet skid tests, carbon black is covered by rubber whereas silica particles are at least partly exposed. In this report, the experimental results of the effects of carbon black and silica on wet skid resistance measured by various test methods and under different conditions are explained based on the “Three Zone Concept” of the contact area of tread compounds with the track surface during sliding or rolling. The three zones are water film squeezing, transition and traction zones. In the first two zones, where hydro-dynamic and micro-elastohydrodynamic lubrication mechanisms are dominant, silica is beneficial for wet friction. In the traction zone, where friction is governed by boundary lubrication, carbon black is preferred. Under test conditions where the water squeezing and transition zones are more developed, such as at high speed, lower temperature, smoother track surface, lower load, higher slip angle, and ABS brake, the silica shows better performance, but otherwise where the traction zone is larger, carbon black gives higher wet skid resistance. Accordingly, a new carbon-silica dual phase filler CSDPF 4210 that is characterized by high surface coverage with silica has been developed. With this material, the wet skid resistance of a passenger tire on a car with ABS at high speed and smooth road surface is significantly improved.
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Jiang, Yin Fang, Lei Fang, Zhi Fei Li, and Zhen Zhou Tang. "Study on the Formability of Square Box Deep Drawing of Tailor Rolling Blanks." Key Engineering Materials 464 (January 2011): 469–73. http://dx.doi.org/10.4028/www.scientific.net/kem.464.469.
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As a new lightweight structural sheet metal, tailor rolled blanks has a good prospect in the future development of the automobile industry, and its formability is the current research focus. We use ABAQUS software to analyze the impacts of blank holder force, thickness ratio, die radius, shape and size of sheet metal on the movement of the transition zone and thickness direction strain on the formability of square box of tailor rolled blanks in deep drawing. The results show that, generally, in the punch and side wall corner, where thinning is more serious is a dangerous rupture area, while the inner edge of flange part is prone to wrinkle. When the BHF is 140kN, the connection between the thin side and the transition zone where thinning is severe is also a dangerous area, and even more serious, likewise when the blank thickness ratio arrives at 1.4mm/0.8mm, or the blank size 260mm*260mm, thinning is very serious at the connection between the thin side and the transition zone which is a dangerous rupture area.
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Samiian, Laila, Dale F. Kraemer, Ryan Butterfield, and Sarah Rausch Osian. "Breast cancer disparities in Duval County, Florida." Journal of Clinical Oncology 31, no. 26_suppl (2013): 117. http://dx.doi.org/10.1200/jco.2013.31.26_suppl.117.
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117 Background: The age-adjusted death rate from breast cancer in Duval County is higher than the national average, with 26 deaths per 100,000 for all women. Breast cancer mortality is 38% higher for black women (37 per 100,000) in Duval County, than for white women (24 per 100,000). We sought to evaluate county specific breast cancer disparity data, in an effort to begin designing effective targeted interventions to reduce the disparities. Methods: Data on female breast cancer cases from 2004-2010 was extracted using the Florida Cancer Data System (FCDS). This data was analyzed using traditional descriptive statistics. Additional classification included health zones within Duval County, race, insurance, and age. Government (Tricare) and private or commercial insurance were combined in one group. The primary outcome was Stage at diagnosis, and time from diagnosis to treatment. Results: Using the FCDS, 6,502 new breast cancers were identified in Duval County from 2004–2010. Of these women, 73% were white, 24% black, 5% Hispanic, 2% Asian, and 2% unknown/other. Health Zone 1 which represents the urban core, has the largest population of Black women with breast cancer (76%), followed by health zone 5 and 4 (35% and 19%). Health Zone 1 has the highest volume of uninsured (10% vs 4% average for zones 2-6), and Medicaid breast cancer patients (8% vs 4% average for zones 2-6), and the lowest number of breast cancer patients with Government/Private insurance (33% vs 56%). Black women had higher percentage of advanced stage IV disease than any other race (8 % vs 4 %, p< .001). Women in Health Zone 1 are more likely to present with stage IV breast cancer than any other health zone in Duval County (10% vs 5%, p<0.01). Medicaid patients followed by the uninsured had the highest rate of stage IV at diagnosis (20% and 12% vs 4%, p<.001). Time from diagnosis to treatment was found to be longest in Black women (29 days vs 26 days, p< .001), Health Zone 1 (30 days vs county average 27 days, p<. 001), and those who were uninsured or had Medicaid (34 days vs 25 days for private insurance, p<0.001). Conclusions: Living in the urban core, black race, lack of insurance, and Medicaid funding was significantly associated with advanced stage at diagnosis and longer time from diagnosis to treatment in Duval County, Florida.
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Sawłowicz, Zbigniew, Łukasz Malinowski, Andy Giże, Jan Stanek, and Jerzy Przybyło. "Mineralogical-Geochemical Study of Corroded Iron-Based Metals from a Salt Mine Environment." Corrosion 76, no. 7 (2020): 666–77. http://dx.doi.org/10.5006/3493.
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Metal fragments (pipe, chain, valves), at advanced stages of corrosion, were collected underground in the Wieliczka salt mine. Macroscopically distinct zones of corroded material, as well as black blisters on the surface of different metal fragments, were studied using scanning electron microscopy with energy dispersive spectrometry (SEM-EDS), x-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and Mössbauer spectroscopy (MS). SEM-EDS studies showed various morphological forms with different chemical compositions. The original outer zone of the iron artifacts is mainly composed of aggregates of needle-shaped goethite crystals with idiomorphic crystals of halite. A subsequent zone, toward the inner margin, is composed mainly of fine granular aggregates of magnetite. Goethite (α-FeOOH) and akaganeite (β-FeOOH) form spherical, fibrous, and structureless aggregates in the next internal zone. Forms of aggregates seem to depend on the chloride content, 1 wt% to 3.5 wt% Cl in the structureless aggregates and 5 wt% to 9 wt% Cl in the regular ones. In addition, in the internal zone crystals of lepidocrocite form rosettes. Blisters are built of the acicular akaganeite crystals, which form fibrous aggregates in the shell and spherical ones in the interior. The relative concentrations of iron bearing minerals in the studied zones, i.e., akaganeite, hematite, goethite, magnetite, and lepidocrocite are established. Where they dominate, the zones are: black (magnetite), orange (goethite, lepidocrocite, akaganeite), and light brown (goethite).
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Mori, Ken-ichiro, Yasutaka Suzuki, Daisuke Yokoo, Michiya Nishikata, and Yohei Abe. "Steel sheets partnered with quenchable sheet in hot stamping of tailor-welded blanks and its application to separation prevention of fractured components." International Journal of Advanced Manufacturing Technology 111, no. 3-4 (2020): 725–34. http://dx.doi.org/10.1007/s00170-020-06100-4.
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Abstract The phase transformation and mechanical properties of non-quenchable steels partnered with the quenchable boron steel in hot stamping of tailor-welded blanks were evaluated to produce tailored components with partially balanced strength and ductility. The effect of the forming start temperature after natural air cooling on the phase transformation and mechanical properties for 270 MPa mild steel, non-quenchable steel, 440 MPa high strength steel, and 22MnB5 steel sheets was examined, and the 270 MPa and non-quenchable sheets had enough ductility after hot stamping. Tailored components having a hardness of about 500 HV1 in the high strength zone and a total elongation of about 30% in the high ductility zone were hot-stamped from a tailor-welded blank composed of 22MnB5 and 270 MPa sheets. It was found that the 270 MPa mild steel sheet is sufficient as a partner sheet of tailor-welded blanks. In addition, the safety of hot-stamped components was heightened by welding a 22MnB5 main blank with a 270 MPa steel patch. Even if the main blank is fractured by a collision, the hot-stamped component is not separated by the 270 MPa patch having high ductility.
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Pyle, Leanne J., Christopher R. Barnes, and Lee McKenzie McAnally. "Conodont biostratigraphy of the latest Cambrian - Early Ordovician upper McKay Group, southeastern British Columbia." Canadian Journal of Earth Sciences 44, no. 12 (2007): 1713–40. http://dx.doi.org/10.1139/e07-047.
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The age of the upper McKay Group based on conodont biostratigraphy is latest Cambrian (Cordylodus proavus Zone) to late Early Ordovician (middle Floian; Oepikodus communis Zone). A collection of 12 940 conodont elements was recovered from 306 samples of upper McKay Group strata exposed in the Western Main Ranges of the southern Canadian Rocky Mountains, southeastern British Columbia. The conodont fauna is assigned to 53 species representing 30 genera. Twelve zones are recognized, two of which are cosmopolitan: Cordylodus proavus Zone and Iapetognathus Zone. Seven Midcontinent Realm zones, in ascending order, include Polycostatus falsioneotensis, Rossodus tenuis, Rossodus manitouensis, low diversity interval, Scolopodus subrex, and Acodus kechikaensis zones, and Tropodus sweeti Subzone (of the Oepikodus communis Zone). Three Atlantic Realm zones, in ascending order, include Cordylodus angulatus, Acodus deltatus, and Paroistodus proteus zones. The zonation for the upper McKay Group establishes correlation with the Survey Peak Formation and lower Outram Formation of the Bow Platform, and with the Kechika Formation and lower Skoki Formation of the Macdonald Platform and Kechika Trough in the northern Rocky Mountains. The McKay Group represents deposition during post-rift thermal subsidence of the margin, although its thickness, abrupt transition to black shale of the overlying Glenogle Formation, and intercalation of volcanogenic rocks imply a history of differential subsidence similar to that of the northern Cordillera, probably related to periodic extension.
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Lamprecht, K., and Manfred Geiger. "Experimental and Numerical Investigation of the Formability of Laser Welded Patchwork Blanks." Advanced Materials Research 6-8 (May 2005): 689–96. http://dx.doi.org/10.4028/www.scientific.net/amr.6-8.689.
Full textAbstract:
Within the past decades tailored welded blanks have become a key product for the construction of lightweight automotive bodies. Following the principle of applying material only where it is really needed results in an improved stiffness and crash worthiness of the body-in-white, while at the same time weight and production costs may be reduced. An alternative to the concept of tailored blanks is the so-called patchwork blank technique. The principle of patchwork blanks is to add a flat piece of sheet metal onto the main blank in the areas where reinforcements are required. The assembly can be done by adhesive bonding, resistance spot welding or laser welding prior to forming. The major benefits of this technique in comparison to tailored blanks are the abolition of cutting operations and a high flexibility regarding the shape and position of the reinforcement. Even if there is a big application potential for patchwork blanks in automobile production, practical realisation of this innovative technique is hindered due to a lack of knowledge regarding the formability of patchwork blanks. In this study the formability of laser welded patchwork blanks is investigated by means of experimental trials and finite element analysis. In order to simulate accurately the forming processes of patchwork blanks using finite element analysis, knowledge about the characteristics of the weld metal, including the weld bead and the heat affected zone, is essential. Microhardness measurements have been applied to analyse the heat affected zone and to determine its lateral dimensions. The constitutive behaviour of the weld metal has been investigated by uniaxial tensile tests with a special sample geometry. The results obtained from these experimental investigations have been used to define different modelling techniques for the finite element analysis of patchwork blank forming processes. It can be shown that the consideration of the modified material properties along the weld seam leads to an improvement of the accuracy of the numerical calculation.
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Liu, XiaoHang, and Alexis Martinez. "Areal Interpolation Using Parcel and Census Data in Highly Developed Urban Environments." ISPRS International Journal of Geo-Information 8, no. 7 (2019): 302. http://dx.doi.org/10.3390/ijgi8070302.
Full textAbstract:
Areal interpolation is routinely used when spatial data are unavailable at desired geographical units. While many methods are available, few of them were developed specifically for and tested in highly developed urban cores. Even fewer studied subpopulation or population characteristics. This paper explores both issues using parcel map and decennial census data as ancillary information. Using census blocks as intermediate zones, the method first disaggregates source-zone data to intermediate zones, then disaggregates data to parcel level in intermediate zones intersecting target zones, and finally aggregates intermediate-zone and parcel-level estimates to obtain target-zone estimates. Compared to areal weighting and residential proportion, the proposed method is significantly more accurate. All three methods perform the best on population count, and worst on spatially clustered subpopulations such as black/African American population. Quotient variables are more difficult to interpolate than count variables. The research demonstrates the utility of parcel and decennial census data for areal interpolation in highly developed urban cores, and calls for future research on subpopulation and population characteristics.
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Liao, Xin, Wenda Zhang, Jiannan Chen, et al. "Deterioration and Oxidation Characteristics of Black Shale under Immersion and Its Impact on the Strength of Concrete." Materials 13, no. 11 (2020): 2515. http://dx.doi.org/10.3390/ma13112515.
Full textAbstract:
Black shale, which usually contains pyrite, is easily oxidized and generates acid discharge. This acidic environment is not favorable for concrete in engineering applications and is likely to affect the durability of engineering structures. This study investigated the effect of acid discharge from the weathering of black shale on the strength of concrete under partially immersed conditions. Black shale concrete immersion tests were conducted at different immersion depths to evaluate the oxidation conduction of black shale. Water chemistry and oxidation products were monitored during and after the immersion tests. The quality and strength of the black shale and concrete specimens were obtained before and after the immersion by testing the ultrasonic wave velocity and uniaxial compressive strength. The results indicated that a lower immersion depth of black shale reveals a higher degree of oxidation, and the capillary zone in black shale is critical for black shale oxidation in terms of mass transfer. The ultrasonic velocity of the concrete showed different change patterns in the immersed and non-immersed zones. Precipitation and additional hydration enhanced the quality and entirety of the concrete (increased ultrasonic velocity) at the non-immersed or partially-immersed zones, while the dissolution of concrete was dominant in the immersed zone (decreased ultrasonic velocity) and induced a reduction of concrete quality. The compressive strength of the concrete was enhanced after immersion. The concrete strength slightly increased by 5–15%. This phenomenon is attributed to the filling of the voids by the precipitations of minerals, such as goethite and anhydrite.
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Voitenko, S., and O. Sydorenko. "The influence of the natural-climate zone on the cattle productivity of Ukrainian Black-and-White Dairy breed." Tehnologìâ virobnictva ì pererobki produktìv tvarinnictva, no. 2(158) (November 24, 2020): 58–65. http://dx.doi.org/10.33245/2310-9289-2020-158-2-58-65.
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It has been highlighted the data of researches as for the influence of natural and climatic zones of Ukraine on display of economically useful signs of the most numerous cattle in the country like Ukrainian black-spotted dairy breed. It was the grounds to assert the efficiency of resources use in those conditions to which they are most adapted and have genetically determined potential. It was found that cowsof lactation breeding herds in the Forest-steppe zone produced 7344 kg of milk, which is 242 kg and 1125 kg more than in the Steppe and Polissya regions due to significant variation of the characteristic within each climatic zone (Cv = 11.6– 27,5%). The Polissya zone, where the animals' yieldwere 5764 kg, while in other climates 6982–6992 kg, does not contribute to the high productivity of the first lactation cows. It is proved that the duration of the service period in cows of three natural and climatic zones of Ukraine varied from 106 days in Polissya to 126 days – Forest-steppe, but it did not agree with the output of calves per 100 cows, which in 81 Polissya amounted to 82 and Forest-steppe – 79. The heifers of the Steppe zone are inseminated with live weight of 391 kg at the age of 477 days, and the Forest-steppe and Polissya with slightly less 385 kg and 387 kg, respectively, at the age of 493 days and 517 days. There is no significant difference in live weight at the ages of 6, 12 and 18 months between heifers of different natural and climatic zones of Ukraine, but the degree of development of the trait after 6 months was slightly better in cattle of the Steppe zone. A positive correlation was found between milk yield of first lactation cows of all natural climatic zones and their live weight at 6, 12 and 18 months of age, as well as negative calf age at first insemination (-0.587 ... -0.810) with significant correlation from the cattle of the Steppe zone. A high correlation coefficient (+0.703) was found in cows between live weight of heifers at first insemination and first lactation in the Polissya region. Key words: natural and climatic zones, Ukrainian Black-and-White Dairy breed, cows, yield, lactation, live weight, reproductive ability indicators, selection traits.
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Zamaslo, O. T., and D. A. Kozak. "Laundering Black Money by Means of Offshore Zones: The Negative Impact and Ways to Resolve." Business Inform 8, no. 523 (2021): 140–50. http://dx.doi.org/10.32983/2222-4459-2021-8-140-150.
Full textAbstract:
The article is aimed at examining the problem of laundering black money in the offshore jurisdictions. Attention is paid to the key factors that attract economic entities regarding business registration in offshore zones. The impact of the tax burden on the process of moving profits to offshore jurisdictions is considered. The volumes of losses of the State Budget of Ukraine related to tax evasion of the funds placed on the accounts of offshore companies have been studied. The most typical schemes of laundering black money in offshore zones are presented, as well as a number of stages that form the process of laundering are highlighted. Emphasis is placed on round tripping investment as a key mechanism for returning foreign funds to a resident in the form of foreign direct investment, the main factors in the use of round trip transactions by Ukrainian business entities are allocated. Attention is drawn to the percentage of countries, which are the largest investors in Ukraine. It is determined that the use of offshore schemes by Ukrainian businesses contributes to the growth of the shadowing of the national economy and causes a direct negative impact on Ukrainian financial security, which is confirmed by the results of the National Risk Assessment 2019. Emphasis is placed on the OECD / G20 Base Erosion and Profit Shifting (BEPS) initiative to prevent money laundering offshore, and Ukraine’s key measures to implement relevant international standards are specified. Prospects for further research in this direction are to identify measures directed towards deoffshorization of the national economy, including through the implementation of the BEPS 2.0 Action Plan.
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Doucet, René. "La Régénération préétablie dans les peuplements forestiers naturels au Québec." Forestry Chronicle 64, no. 2 (1988): 116–20. http://dx.doi.org/10.5558/tfc64116-2.
Full textAbstract:
The type and abundance of advance growth has been evaluated in 421 areas representing the major forest cover types in Quebec. Advance growth has been found to be abundant in mature stands of every cover type, except jack pine, and in all ecological zones. However its composition varied with cover types: balsam fir was the main species of advance growth in fir and mixedwood stands, while black spruce dominated advance growth in black spruce and jack pine stands. Most of the black spruce advance growth was from layer origin, especially in the black spruce ecological zone. Key words: Québec, regeneration.
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Jiang, Yin Fang, Lei Fang, Zhi Fei Li, and Zhen Zhou Tang. "Formability Window of Tailor Rolled Blanks at Blank-Holder Force." Advanced Materials Research 156-157 (October 2010): 488–91. http://dx.doi.org/10.4028/www.scientific.net/amr.156-157.488.
Full textAbstract:
As a new lightweight material and new technique,Tailor Rolled Blanks has a good prospect in energy-saving environmental protection and the future development of the automobile industry, formability window of Tailor Rolled Blanks at blank-holder force has important practical significance. Based on the research of a square box TRB, the paper proposes a theory of TRB’ formability window, also with the usage of an ABACUS finite element software to simulate the TRB sheet in the course of the critical wrinkling BHF curve and critical fracture BHF curve, to establish TRB formability window under the condition of blank holder force. The results not only show that the square box of TRB has the security zone in the deep drawing process, but also has got the wrinkling and fracture areas of the square box.
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Dribnenki, J. C. P., A. G. Green, and G. N. Atlin. "Linola™ 989 low linolenic flax." Canadian Journal of Plant Science 76, no. 2 (1996): 329–31. http://dx.doi.org/10.4141/cjps96-057.
Full textAbstract:
Linola™ 989 is the second low linolenic flax cultivar registered in Canada. In western Canada, Linola™ 989 is significantly earlier maturing than Linola™ 947 and Flanders, and has a significant yield advantage over Linola™ 947 in the Black and Brown soil zones. Linola™ 989 is significantly higher yielding than Flanders in the Black soil zone of Saskatchewan and Manitoba. Both Linola cultivars are yellow seeded. Key words: Flax, low linolenic acid, cultivar description, solin
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King, George A. "Vegetation and pollen relationships in eastern Canada." Canadian Journal of Botany 71, no. 2 (1993): 193–210. http://dx.doi.org/10.1139/b93-022.
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The relationship between the vegetation and modern pollen assemblages in eastern Canada is summarized and analyzed using isopoll maps, ordination, and cluster analysis. The major vegetation zones are shrub tundra, forest tundra (divided into shrub and forest subzones), lichen woodland, closed black spruce forest, mixed boreal forest, and coastal barrens. The pollen assemblages of these zones are distinguished by differences in the relative abundance of a few important pollen types rather than by floristic differences. Northern zones have relatively high Cyperaceae and low Picea pollen percentages, and southern zones have high Picea and Abies pollen percentages. Surface samples from each vegetation zone generally form distinctive groups in the ordination analysis. However, samples from the shrub subzone of the forest tundra cluster with shrub tundra samples, and lichen woodland samples cluster with samples from the closed black spruce forest and the forest subzone of the forest tundra. Cluster analysis separates the samples into geographically distinct groups. However, these groups generally contain samples from several vegetation zones. The surface sample data set analyzed here will prove useful in reconstructing the vegetation history of the region. Key words: pollen surface samples, modern vegetation, eastern Canada.