This paper describes a methodology for capturing the tacit knowledge of the manual grinding and polishing process. Key Process Variables (KPVs) i.e. contact force, tool path, feed rate, etc. of the ...manual operator performing the task are captured with a `sensorised' hand-held belt grinder, while the changes to the work-piece geometry is captured using a 3-D laser scanner. These KPVs are fed into an analytical material removal model to generate a material removal profile, which can then be calibrated using the actual material removed determined from the manual surface finishing process. The skill of the surface finishing skill is encapsulated in this material removal model and reduces the need for costly robotic Design of Experiment (DoE) trials with test coupons to develop empirical material removal models. Parts from the production process require different processing variables, but the common objective is to generate various material removal maps in order to manufacture a part of a desired form and dimension. The metal removal rate (MRR) model could then be utilized by the industrial robot to determine suitable polishing parameters to accomplish the polishing task. The characteristics of the skilled worker's captured motions can then be extracted and used for optimization of the industrial robot polishing tool path.
Inhibitors of farnesyltransferase are effective against a variety of tumors in mouse models of cancer. Clinical trials to evaluate these agents in humans are ongoing. In our effort to develop new ...farnesyltransferase inhibitors, we have discovered bioavailable aryl tetrahydropyridines that are potent in cell culture. The design, synthesis, SAR and biological properties of these compounds will be discussed.
In our effort to develop new farnesyltransferase inhibitors, we have discovered bioavailable aryl tetrahydropyridines that are potent in cell culture. The design, synthesis, SAR and biological properties of these compounds will be discussed.
The active principle of Artemisia annua L., artemisinin, is currently being developed to a registered antimalarial drug. For production purposes, plants with a high artemisinin content are required. ...The development of the artemisinin content and of the biosynthetically related sesquiterpenes artemisinic acid, arteannuin B, and artemisitene was observed in A. annua plants, during a vegetation period in Vietnam, where this species is indigenous. In addition, the essential oil content and composition were studied. Samples of leaves, buds, flowers, or post-bloom flowers and fruits were taken at different stages: vegetative (5, 6, and 8 months old), at mass formation of buds (9 months), at full bloom (10 months), and post-bloom (10.5 months). The highest artemisinin content (0.86% dry weight) was present in the leaves of 5 months-old plants. At this stage also the highest leaf yield was found. Subsequently, the artemisinin content gradually dropped. At the age of 5 months the highest artemisinic acid and arteannuin B contents, 0.16 and 0.08% dry weight, respectively, were found as well. Artemisitene was present at all stages of development, ranging from 0.002 to 0.09% dry weight. With 1.9% v/w, the essential oil content was maximal just before flowering and was composed of 55% monoterpenes and 45% sesquiterpenes. At all other stages (0.4-1.0% v/w oil) this ratio was ca. 30%/70%. The main components of the oil were camphor and germacrene-D.
We demonstrate a high dynamic range Josephson parametric amplifier (JPA) in which the active nonlinear element is implemented using an array of rf-SQUIDs. The device is matched to the 50 \(\Omega\) ...environment with a Klopfenstein-taper impedance transformer and achieves a bandwidth of 250-300 MHz, with input saturation powers up to -95 dBm at 20 dB gain. A 54-qubit Sycamore processor was used to benchmark these devices, providing a calibration for readout power, an estimate of amplifier added noise, and a platform for comparison against standard impedance matched parametric amplifiers with a single dc-SQUID. We find that the high power rf-SQUID array design has no adverse effect on system noise, readout fidelity, or qubit dephasing, and we estimate an upper bound on amplifier added noise at 1.6 times the quantum limit. Lastly, amplifiers with this design show no degradation in readout fidelity due to gain compression, which can occur in multi-tone multiplexed readout with traditional JPAs.
Introduction: Regeneration of CD4+ T lymphocytes has been shown to be thymus-dependent in bone marrow transplant recipients and after intensive chemotherapy. The rate of CD4+ T cell regeneration is ...correlated positively with enlargement of the thymus, as shown on radiographs, and higher rates of CD4+ T lymphocyte regeneration were observed in children as compared with adults, consistent with thymic function diminishing with age. We hypothesized that in HIV infected patients CD4+ T cell recovery during highly active antiretroviral therapy (HAART) may also be thymus dependent. Therefore, repopulation of naive (CD45RA+), memory (CD45RO+) and total CD4+ T lymphocytes and total CD8+ T lymphocytes in peripheral blood was assessed in 13 HIV infected children during the initial 3 months of HAART. Results: Significantly higher recovery rates of naive, memory and total CD4+ T cells were observed in children below the age of 3 years as compared with older children. Kinetics of total CD8+ T cells showed no relation to age. Moreover, recovery rates of naive CD4+ T cells in patients below 3 years of age were 10-40 fold higher as compared with previously reported naive CD4+ T cell recovery rates in adults on HAART. Conclusions: High recovery rates of naive, memory and total CD4+ T cells can be achieved in children below 3 years of age. Changes in CD8 counts did not correlate with age. These results indicate that regeneration of CD4+ T cells during HAART may be a thymus-dependent process.
Knowledge of the small strain stiffness of the heavily overconsolidated Gault Clay, which has up to 30% calcium carbonate content, is rather limited. This has resulted in some difficulties in the ...analysis and design of structures constructed in the Gault. In this Technical note, the small strain stiffness of the Gault Clay is examined based on results from triaxial tests with internal small strain measurements, published geophysical data, and values deduced from the back-analysis of full-scale field observations of an excavation at Lion Yard Cambridge, U.K. Comparisons of stiffness values have also been made between the Gault Clay and the non-carbonate heavily overconsolidated London Clay. The results of these examinations have led to the conclusion that the stiffness-strain characteristic of Gault Clay is highly non-linear and exhibits first yield at a threshold shear strain of about 10−5, beyond which the stiffness deteriorates dramatically from an initially very high value. After modest straining the stiffness reduces to values comparable to those for London Clay. The Gault Clay behaves like a low plasticity clay at small strains but as a high plasticity clay at medium to large strains. This behaviour is probably due to the breakdown of the weakly cemented bonding caused by the calcium carbonate content.
We present a proposal for a cold copper distributed coupling accelerator that
can provide a rapid route to precision Higgs physics with a compact 8 km
footprint. This proposal is based on recent ...advances that increase the
efficiency and operating gradient of a normal conducting accelerator. This
technology also provides an $e^{+}e^{-}$ collider path to physics at multi-TeV
energies. In this article, we describe our vision for this technology and the
near-term R&D program needed to pursue it.
The TiO 2 nanorod array (TiO 2 -NA) acting as electron transport layer (ETL) is incorporated with the perovskite solar cells (PSCs). The composition of perovskite is carefully optimized to achieve ...uniform films on the nanostructured ETL. The concentration of chlorine (Cl) has huge impact on the morphology of the perovskite layer deposited on TiO 2 -NA. Meanwhile, the incorporation of TiO 2 -NA enhances the extraction efficiency of the carrier due to the increased charge extraction area in the solar cell devices.
The Japanese atomic bomb survivors and three other cohorts of children exposed to radiation are analyzed, and evidence is found for a reduction in the radiation-induced relative risk of cancers other ...than leukemia with time following exposure. Multiplicative adjustments to the excess risk either of the form exp-δ · (time since exposure) or of the form $\text{time since exposure}^{\gamma}$ give equivalent goodness of fit. Using the former type of adjustment an annual overall reduction of 6.9-8.6% in excess relative risk is indicated (depending on the year after which this reduction might take effect). Using the second type of multiplier an adjustment to the excess relative risk varying between $\text{time after exposure}^{-2.0}$ and $\text{time after exposure}^{-3.2}$ fits best overall. All these reductions are statistically significant at the 5% level. There is no significant variation by cohort, by sex, by cancer type, or by age at exposure group in the degree of annual reduction in excess relative risk. Although time-adjusted relative and absolute risk models give equivalently good fits within each cohort, there is significant variation between cohorts in the degree of increase of risk with time in the absolute risk formulation, in contrast to the lack of such heterogeneity for the relative risk formulation. It is shown that if the range of observed reductions in relative risk is assumed to operate 40 or more years after exposure in the youngest age groups, the calculated UK population risks would be reduced by 30-45% compared to those based on a constant relative risk model.
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