Slip Control System for a Deep-Sea Mining Machine

Tracked vehicles capable of locomotion in the deep sea are used for manganese nodule mining. This requires specific technical solutions in various respects. Locomotion in the soft sea bed is one of them. For the Crawler to safely maneuver, an automatic drive mode with slip control of the driving tracks is essential. Based on experimental studies at IKS, University of Siegen, slip control for the NIOT-IKS mining machine has been developed and implemented. The experimental setup for the development of the slip control along with the logic of the automatic driving mode is described. The system is critically discussed and the test results and future work are briefly outlined. Note to Practitioners-The work is carried out as part of the polymetallic nodule mining program of the Government of India. The technique of slip control is a specific requirement for a tracked vehicle used in the deep sea. Slip is common in many vehicles-tracked and otherwise. Examples are steam engines in the early days and ordinary cars while negotiating slush or snow/ice and dozers working in soft soil. While these are manually controlled by drivers who have firsthand knowledge of the environmental conditions, in the case of a mining machine in deep sea, it has to be completely automatic and, hence, is challenging. The knowledge generated in this work could be effectively used by practitioners in other related areas of automobile engineering for updating their expertise. Also, similar techniques may be used for maneuvering vehicles sent to other planets     

Expression of INK4 inhibitors of cyclin D-dependent kinases during mouse brain development

In situ hybridization of mouse embryo sections demonstrated expression of mRNAs encoding two polypeptide inhibitors (p18INK4c and p19INK4d) of cyclin D-dependent kinase (CDK) 4 and CDK6 in the central nervous system. No expression of two other INK4 members, p16INK4a and p15INK4b, was observed. The p19INK4d and p18INK4c proteins formed complexes with either CDK4 or CDK6 in a temporal pattern consistent with the results of in situ hybridization. Expression of INK4c was observed at embryonic day 13.5 in neuroepithelial zones of the developing brain, being restricted to dividing neuroblasts but absent from differentiating postmitotic neurons. In the neocortex, p18INK4c was expressed precisely at those developmental stages when neuroblasts switch from a symmetric to an asymmetric pattern of cell division with concomitant increases in their G1 interval. INK4d RNA was detected from embryonic day 11.5 onward, at higher levels than INK4c and with a distinctly different spatial and temporal pattern. Marked INK4d expression was seen in dorsal root ganglia, spinal cord, and focally throughout the brain, but primarily in postmitotic neurons. Neural expression of INK4d continued postnatally into adulthood in postmitotic cells of the dentate gyrus, the pyramidal layer of the hippocampus, and in discrete regions of the cerebral cortex, cerebellum, thalamus, and brainstem. Downregulation of p19INK4d in the dentate gyrus after kainic acid-induced seizures indicated that its expression could also be modified in nondividing cells by excitotoxic stress. Therefore, p19INK4d may contribute to maintaining the quiescent state, acting as a buffer to prevent reactivation of cyclin D-dependent kinases in terminally differentiated cells.     

Malignoma versus bacterial spondylodiscitis: value of spinal MRI for the differential diagnosis in an emergency situation. Description in an acute case with progressive paraplegia

BACKGROUND: For the radiation oncologist in an emergency situation with acute progressive paraplegia distinguishing between benign versus malignant vertebral compression fracture without known malignoma may cause a severe diagnostic problem, when a rapid therapeutic decision is required. PATIENT AND METHOD: A case of an elderly diabetic patient with acute onset of a progressive neurologic deficit is reported. No malignancy was known so far. The CT of the spine showed a destruction of the 7th and 8th thoracic vertebral body with compression of the spinal cord. The patient was referred to the radiotherapist for radiation of a presumed malignant spinal process. RESULT: For differential diagnosis a magnetic resonance imaging (MRI) of the spine was performed and could lead to the correct diagnosis of an infectious spondylodiscitis. CONCLUSION: The MRI of the spine has a potential role for correct differentiation between benign and malignant spinal lesions and may thereby assist the radiotherapist in the decision making in an emergency situation.     

Si/SiGe n-MODFETs on thin SiGe virtual substrates prepared by means of He implantation

Si/SiGe n-type modulation-doped field-effect transistors grown on a very thin strain-relieved Si/sub 0.69/Ge/sub 0.31/ buffer on top of a Si(100) substrate were fabricated and characterized. This novel type of virtual substrate has been created by means of a high dose He ion implantation localized beneath a 95-nm-thick pseudomorphic SiGe layer on Si followed by a strain relaxing annealing step at 850/spl deg/C. The layers were grown by molecular beam epitaxy. Electron mobilities of 1415 cm/sup 2//Vs and 5270 cm/sup 2//Vs were measured at room temperature and 77 K, respectively, at a sheet carrier density of about 3/spl times/10/sup 12//cm/sup 2/. The fabricated transistors with Pt-Schottky gates showed good dc characteristics with a drain current of 330 mA/mm and a transconductance of 200 mS/mm. Cutoff frequencies of f/sub t/=49 GHz and f/sub max/=95 GHz at 100 nm gate length were obtained which are quite close to the figures of merit of a control sample grown on a conventional, thick Si/sub 0.7/Ge/sub 0.3/ buffer.     

A Micellar Route to Ordered Arrays of Magnetic Nanoparticles: From Size‐Selected Pure Cobalt Dots to Cobalt–Cobalt Oxide Core–Shell Systems

Starting with Co‐salt‐loaded inverse micelles, which form if the diblock copolymer polystyrene‐block‐poly(2‐vinylpyridine) is dissolved in a selective solvent like toluene and CoCl₂ is added to the solution, monomicellar arrays of such micelles exhibiting a significant hexagonal order can be prepared on top of various substrates with tailored intermicellar distances and structure heights. In order to remove the polymer matrix and to finally obtain arrays of pure Co nanoparticles, the micelles are first exposed to an oxygen plasma, followed by a treatment in a hydrogen plasma. Applying in‐situ X‐ray photoelectron spectroscopy, it is demonstrated that: 1) The oxygen plasma completely removes the polymer, though conserving the original order of the micellar array. Furthermore, the resulting nanoparticles are entirely oxidized with a chemical shift of the Co 2p_3/2 line pointing to the formation of Co₃O₄. 2) By the subsequent hydrogen plasma treatment the nanoparticles are fully reduced to metallic Co. 3) By exposing the pure Co nanoparticles for 100 s to various oxygen partial pressures pequation/tex2gif-inf-5.gif, a stepwise oxidation is observed with a still metallic Co core surrounded by an oxide shell. The data allow the extraction of the thickness of the oxide shell as a function of the total exposure to oxygen (pequation/tex2gif-inf-7.gif × time), thus giving the opportunity to control the ferromagnetic–antiferromagnetic composition of an exchange‐biased magnetic system.     

"即连即铸"的奥钢联连铸技术

1前言 生产率和作业率方面的收益以及可能性调整的灵活性是提高钢铁工业竞争力的关键因素.     

Site-directed mutagenesis of recombinant human beta 2-glycoprotein I identifies a cluster of lysine residues that are critical for phospholipid binding and anti-cardiolipin antibody activity

beta2-Glycoprotein I (beta2GPI) is a phospholipid-binding serum protein with anticoagulant properties. It plays a vital role in the binding of anti-cardiolipin Abs purified from patients with autoimmune disease when assayed in a cardiolipin (CL) ELISA. Based on a three-dimensional model of beta2GPI, electrostatic calculations, and earlier peptide studies, a highly positively charged amino acid sequence, Lys282-Asn-Lys-Glu-Lys-Lys287, located in the fifth domain of beta2GPI, has been predicted to be the phospholipid binding site. We tested this hypothesis by site-directed mutagenesis of residues in the predicted phospholipid binding site and by assessing the mutants for phospholipid binding and anti-beta2GPI activity. A single amino acid change from Lys286 to Glu significantly decreased the binding of beta2GPI to CL. Double and triple mutants 2k (from Lys286, 287 to Glu286, 287), 2ka (from Lys284, 287 to Glu284, 287), and 3k (from Lys284, 286, 287 to Glu284, 286, 287) possessed no binding of Ab to beta2GPI in a CL ELISA, as well as no inhibitory activity on the binding of iodinated native beta2GPI to CL. These results indicate that the residues Lys284, Lys286, and Lys287 in the fifth domain of beta2GPI are critical for its binding to anionic phospholipids and its subsequent capture for binding of anti-beta2GPI Abs.     

Adaptive flexibility and maladaptive routines in selecting fast and frugal decision strategies.

Decision routines unburden the cognitive capacity of the decision maker. In changing environments, however, routines may become maladaptive. In 2 experiments with a hypothetical stock market game (n = 241), the authors tested whether decision routines tend to persist at the level of decision strategies rather than at the level of options in strategy selection. The payoff structure of the task was changed after 80 decision trials, rendering a new strategy optimal with respect to expected payoff. Whereas most participants detected the appropriate strategy at the beginning of the task, they tended to retain it even when it was no longer optimal. A hint about a possible change had only a small influence on this maladaptive routine; a monetary incentive had none. Switching to a similar but not identical task relaxed the routine, but not much. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On enabling integrated process compliance with semantic constraints in process management systems

Key to broad use of process management systems (PrMS) in practice is their ability to foster and ease the implementation, execution, monitoring, and adaptation of business processes while still being able to ensure robust and error-free process enactment. To meet these demands a variety of mechanisms has been developed to prevent errors at the structural level (e.g., deadlocks). In many application domains, however, processes often have to comply with business level rules and policies (i.e., semantic constraints) as well. Hence, to ensure error-free executions at the semantic level, PrMS need certain control mechanisms for validating and ensuring the compliance with semantic constraints. In this paper, we discuss fundamental requirements for a comprehensive support of semantic constraints in PrMS. Moreover, we provide a survey on existing approaches and discuss to what extent they are able to meet the requirements and which challenges still have to be tackled. In order to tackle the particular challenge of providing integrated compliance support over the process lifecycle, we introduce the SeaFlows framework. The framework introduces a behavioural level view on processes which serves a conceptual process representation for constraint specification approaches. Further, it provides general compliance criteria for static compliance validation but also for dealing with process changes. Altogether, the SeaFlows framework can serve as formal basis for realizing integrated support of semantic constraints in PrMS.