Estimation of the virtual workpiece quality by the use of a spindle-integrated process force measurement

Existing workpiece quality estimations utilize material removal simulations in combination with dynamic force measurements. The common force measurement method, using plate dynamometer, is not practicable due to space-constrains, high costs and inertial forces in case of 5-axis machining that falsify the measurement considerably. This paper examines the potential of workpiece quality monitoring by the use of a spindle-integrated high-resolution force measurement that uses displacement sensors. Considering the experimentally determined transfer-function between the force at the TCP and the displacement sensor, it is possible to calculate cutting forces during machining. The virtual quality is compared with CMM measurements.     

Phytase Activity from Lactobacillus spp. in Calcium-Fortified Soymilk

Abstract: The presence of phytate in calcium-fortified soymilk may interfere with mineral absorption. Certain lactic acid bacteria (LAB) produce the enzyme phytase that degrades phytates and therefore may potentially improve mineral bioavailability and absorption. This study investigates the phytase activity and phytate degradation potential of 7 strains of LAB including: Lactobacillus acidophilus ATCC4962, ATCC33200, ATCC4356, ATCC4161, L. casei ASCC290, L. plantarum ASCC276, and L. fermentum VRI-003. Activity of these bacteria was examined both in screening media and in calcium-fortified soymilk supplemented with potassium phytate. Most strains produced phytase under both conditions with L. acidophilus ATCC4161 showing the highest activity. Phytase activity in fortified soymilk fermented with L. acidophilus ATCC4962 and L. acidophilus ATCC4161 increased by 85% and 91%, respectively, between 12 h and 24 h of fermentation. All strains expressed peak phytase activity at approximately pH 5. However, no phytate degradation could be observed.     

Assignment of glial brain tumors in humans byin vivo 1H-magnetic resonance spectroscopy and multidimensional metabolic classification

This study presents a simple approach for the noninvasive assignment of glial brain tumors according to malignancy by single-voxel proteon magnetic resonance spectroscopy at short echo times (TE≦50 milliseconds). Based on peak area ratios, a five-dimensional data set was obtained for each investigated subject. This vector was then projected along metabolic coordinates in a two-dimensional metabolic space. These coordinates had been determined in a previous study (Hagberg G et al., 1995,Magn Reson Med 34: 242–252). Tumor assignment was done without any knowledge of histology by comparing the location of the new cases to the features of the previous study. All 11 investigated glioblastomas multiforme, as well as 4 of 5 astrocytomas grade II, could easily be assigned to the groups of high- and low-grade tumors, respectively. Classification was more difficult in the case of a cystic astrocytoma grade II and one astrocytoma grade III. Two spectra measured in normal-appearing matter of glioblastoma patients were not classified as healthy. Using single-voxel proton magnetic resonance spectroscopy at short echo times with the knowledge of a base study, a straightforward, fast, and noninvasive differential diagnosis of glial brain tumors is possible. Supported by the Swiss National Science Foundation Research Grants No. 31-32533.91 (to J.S.) and 32.39773.93 (to W.S.).W.R. and E.W.R. have been supported by the Krebsliga beider Basel. A preliminary account of this work was given at the Third Annual Scientific Meeting of the International Society for Magnetic Resonance in Medicine, Nice, France, August 1995, abstract 1719.     

The Instructional Media for Different Levels in the Philippine Educational System

In the Philippines, the K＋I2 system is newly introduced and the readiness for its implementation undoubtedly made the teaching community confused and confounded. Thus, extra efforts are being done to upgrade and update all instructional materials. Even it＂ the Department of Education are preparing the faculty members through trainings, seminars and providing them with syllabus accompanying the new curriculum, still the confidence for the coming teaching assignments for the additional two years in the system is vet3.＇ Iow~ The faculty members are now strategizing teaching methodology for the subjects they have to handle through upgrading not only their knowledge but also the teaching materials they are to use in their classroom. With the changing environment, the learning style of students also advances. Children are now exposed to various modern gadgets, thus, they learn more advanced knowledge about their environment. These modern medium must be an advantage to the teaching profession. Teachers must know how and what the children learn through these medium and create some learning materials that will augment this knowledge in schools. This study is a partial analysis of the learning style of students in different levels of the educational system and the knowledge they acquire through different modern medium and test the gap between this and the knowledge they must learn in school. Also, this study will come up with what medium can be used as instructional medium that will aid the faculty members in their teaching courses or subjects in school.     

Prostaglandins and prostaglandin intermediates. 25. Synthesis of PGF2α Intermediates by addition of 1-metalated hept-1-ynes to a substituted cyclopentanecarbaldehyde bearing already the complete carboxylic side chain

Starting with the racemic aldehyde 4 , prepared from the tris(trimethylsilyl) ether 3 , the possibility was demonstrated of converting a trimethylsilylated primary hydroxy group with high selectivity into an aldehyde group in the presence of two trimethylsilylated secondary hydroxy groups employing oxalyl chloride and dimethyl sulfoxide (Swern reagent) as oxidant. The alkynylation of this aldehyde with 1-metalated hept-1-yne afforded a chromatographically separable mixture of two diastereomeric alcohols, both being suitable intermediates for the synthesis of PGF_2α. The diastereofacial selectivity of the addition strongly depends on the metal employed. Hept-1-yn-1-yllithium afforded a 67:33 mixture of (13 R*)- and (13 S*)-alcohol, hept-1-yn-1-yltriisopropoxytitanium, however, a 30:70 mixture.     

Production of a carotenoid-rich product by alginate entrapment and fluid-bed drying of Dunaliella salina

A new carotenoid-rich product was formed by entrapment of Dunaliella salina in calcium alginate beads of different alginate concentrations, followed by drying in a fluid-bed dryer. The drying process yielded β-carotene recoveries of between 79 and 89% and produced a change in the 9-cis/all-trans ratio of β-carotene isomers. The carotenoid stability of the product was dependant on both the storage conditions and alginate content (range 3·3–7·3 g litre⁻¹) of the beads. In the presence of light and oxygen total carotenoid degraded following a first order kinetic model with degradation constants between 0·016 and 0·039 days⁻¹, with the lowest degradation occurring with the lowest alginate concentration. Product stored in the dark and flushed with nitrogen produced first-order degradation constants of 0·012 and 0·020 days⁻¹ for the two higher alginate concentrations; that with the lowest alginate content showed no noticeable degradation after 58 days storage. During storage, the 9-cis isomer was significantly more unstable showing a relative loss under all conditions, degrading almost completely when stored in the presence of light and oxygen and reaching an equilibrium ratio with the all-trans isomer when stored in the dark and flushed with nitrogen. © 1998 SCI.