A survey on offline scheduling with rejection

In classical deterministic scheduling problems, it is assumed that all jobs have to be processed. However, in many practical cases, mostly in highly loaded make-to-order production systems, accepting all jobs may cause a delay in the completion of orders which in turn may lead to high inventory and tardiness costs. Thus, in such systems, the firm may wish to reject the processing of some jobs by either outsourcing them or rejecting them altogether. The field of scheduling with rejection provides schemes for coordinated sales and production decisions by grouping them into a single model. Since scheduling problems with rejection are very interesting both from a practical and a theoretical point of view, they have received a great deal of attention from researchers over the last decade. The purpose of this survey is to offer a unified framework for offline scheduling with rejection by presenting an up-to-date survey of the results in this field. Moreover, we highlight the close connection between scheduling with rejection and other fields of research such as scheduling with controllable processing times and scheduling with due date assignment, and include some new results which we obtained for open problems.     

Fabrication of Transparent Silicon Nitride from Nanosize Particles

Compaction of ultrafine silicon nitride (Si₃N₄) powder at high pressures and various temperatures followed by pressureless sintering was investigated. The powder, consisting of nearly spherical particles (16 nm in diameter) of amorphous stoichiometric Si₃N₄, was pressed in a diamond anvil cell under pressures up to 5 GPa and temperatures ranging from liquid nitrogen to 500°C. Quality of compaction, evaluated by visual transparency and hardness of the produced compacts, depended on the amount of adsorbed gases on the surface of the particles and on the temperature of compaction. Visually transparent compacts were produced by pressing the starting powder without outgassing in liquid nitrogen under 5 GPa. The transparent compacts exhibited a hardness of 1200 kg/mm² after pressing in the diamond anvil cell at 500°C for 3 h at 5 GPa. After subsequent pressureless sintering conducted for 1 h at 5 GPa. After subsequent pressureless sintering conducted for 1 h at 1400°C in a tube furnace under nitrogen, the hardness of these samples increased to over 2000 kg/mm² and the visual transparency was maintained. The results demonstrated that transparency was maintained. The results demonstrated that transparent compacts of nanosize amorphous Si₃N₄ particles could be sintered to high hardness at relatively low temperatures without using sintering aids or applying pressure during sintering.     

Peripheral Artery Disease Is Associated with a Deficiency of Erythrocyte Membrane n-3 Polyunsaturated Fatty Acids

Population-based data suggest that individuals who consume large dietary amounts of n-3 polyunsaturated fatty acids (PUFA) have lower odds of peripheral artery disease (PAD); however, clinical studies examining n-3 PUFA levels in patients with PAD are sparse. The objective of this study is to compare erythrocyte membrane fatty acid (FA) content between patients with PAD and controls. We conducted a cross-sectional study of 179 vascular surgery outpatients (controls, 34; PAD, 145). A blood sample was drawn and the erythrocyte FA content was assayed using capillary gas chromatography. We calculated the ratio of the n-3 PUFA eicosapentaenoic acid (EPA) to the n-6 PUFA arachidonic acid (ARA) as well as the omega-3 index (O3I), a measure of erythrocyte content of the n-3 PUFA, EPA, and docosahexaenoic acid (DHA), expressed as a percentage of total erythrocyte FA. Compared with controls, patients with PAD smoked more and were more likely to have hypertension and hyperlipidemia (p < 0.05). Patients with PAD had a lower mean O3I (5.0 ± 1.7% vs 6.0 ± 1.6%, p < 0.001) and EPA:ARA ratio (0.04 ± 0.02 vs 0.05 ± 0.05, p < 0.001), but greater mean total saturated fats (39.5 ± 2.5% vs 38.5 ± 2.6%, p = 0.01). After adjusting for several patient characteristics, comorbidities, and medications, an absolute decrease of 1% in the O3I was associated with 39% greater odds of PAD (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.03–1.86, and p = 0.03). PAD was associated with a deficiency of erythrocyte n-3 PUFA, a lower EPA:ARA ratio, and greater mean total saturated fats. These alterations in FA content may be involved in the pathogenesis or development of poor outcomes in PAD.     

Biochemical Investigation of the Interaction of pICln,RioK1 and COPR5 with the PRMT5–MEP50 Complex

The PRMT5–MEP50 methyltransferase complex plays a key role in various cancers and is regulated by different protein–protein interactions. Several proteins have been reported to act as adaptor proteins that recruit substrate proteins to the active site of PRMT5 for the methylation of arginine residues. To define the interaction between these adaptor proteins and PRMT5, we employed peptide truncation and mutation studies and prepared truncated protein constructs. We report the characterisation of the interface between the TIM barrel of PRMT5 and the adaptor proteins pICln, RioK1 and COPR5, and identify the consensus amino acid sequence GQF[D/E]DA[E/D] involved in binding. Protein crystallography revealed that the RioK1 derived peptide interacts with a novel PPI site.     

Intertemporal and interspatial productivity differentials in U.S. manufacturing

This study analyzes the role productivity plays in explaining the variation in regional manufacturing growth rates. Using the neoclassical growth accounting procedure, we measure productivity from an intertemporal and interspatial perspective. Previous regional studies of U.S. manufacturing look only at the contribution of intertemporal productivity growth in explaning regional growth. These studies ignore the level of productivity and its effect on regional growth. For each year of our study, we rank regions by their interspatial productivity index. We find little difference between the productivity growth rates among the regions of the north and south. Differences among the regions emerge only when we consider interspatial productivity differentials. The North's level of factor productivity is 25 to 30% higher than the South's. The absolute productivity disadvantage of the South, however, is offset by its low input prices. Thus, it is the cost advantage of the South and not its productivity advantage that explains the region's relatively high growth rate.     

Comparing Vacuum and Extreme Ultraviolet Radiation for Postionization of Laser Desorbed Neutrals from Bacterial Biofilms and Organic Fullerenes

Vacuum and extreme ultraviolet radiation from 8 - 24 eV generated at a synchrotron was used to postionize laser desorbed neutrals of antibiotic-treated biofilms and a modified fullerene using laser desorption postionization mass spectrometry (LDPI-MS). Results show detection of the parent ion, various fragments, and extracellular material from biofilms using LDPI-MS with both vacuum and extreme ultraviolet photons. Parent ions were observed for both cases, but extreme ultraviolet photons (16 - 24 eV) induced more fragmentation than vacuum ultraviolet (8 - 14 eV) photons.     

Time dependence of cellular chemical changes induced in prostate PC-3 cancer cells by two structurally related cardenolides monitored by Fourier transform infrared (FT-IR) spectroscopy

Human PC-3 prostate cancer cells were incubated in the presence of two cardenolides, i.e., ouabain and 19-hydroxy-2'-oxovoruscharin. Their effects were monitored by infrared spectroscopy of the cells after different exposure times to the cardenolides. Analysis of changes in absorbance intensities indicated that, for both compounds, the absorbance at one wavenumber with a minor contribution of a second wavenumber is sufficient to build a linear model accurate enough to assign more than 97% of the spectra to their correct time slot. Student t-tests and twodimensional correlation analysis (2D-COS) indicated that both drugs have very similar effects on PC-3 cells. However, asynchronous 2D maps revealed significant differences and allowed the sequence of the spectral changes to be determined: 1395 → 1695 cm(-1) for ouabain, and 1400 → 1655 → 1100 → 1250 → 1020 cm(-1) for 19-hydroxy-2'-oxovoruscharin. 2D correlation map subtraction allowed the identification of very specific differences in the impact of both compounds on PC-3 cells, in particular the ability of 19-hydroxy-2'-oxovoruscharin to affect nucleic acid of PC-3 cells.     

Design approaches for the X band LLRF system

The low-level RF (LLRF) system regulates disturbances over a limited bandwidth in accordance with its capabilities and the RF loop parameters. The disturbances usually originate in the RF system or can be coupled to the RF system from the environment. In this paper a general overview of the possible design approaches for a digital LLRF system operating in X band is presented. Firstly, the possible design approaches of the RF front/back ends are presented and reviewed. We also define the main design parameters for the RF front/back ends. Parameters like isolation between channels, noise, gain, linearity and number of IF stages are put into the perspective of machines using RF components in the X band. An important part of the LLRF system is the local RF timing generation and distribution, which is also treated in the paper. In the second part of the paper the main design approaches in the digital signal processing part of the LLRF system are presented. The emphasis is on the algorithms that are machine specific. Some standard processing algorithms like adaptive feed-forward and arbitrary shaping of feed-forward pulses are presented. Finally, a suggestion for the X band LLRF design is given.     

Bulk Modulus and Young's Modulus of Nanocrystalline γ-Alumina

Compression measurements were performed for the first time on nanocrystalline γ-alumina utilizing a diamond anvil cell (DAC) and the energy dispersive X-ray diffraction method. The cubic unit cell ( a = 0.7924 nm) for γ-alumina was found to have a volume compression of about 2.4% over the pressure range from ambient to 3.8 GPa at room temperature under both hydrostatic and nonhydrostatic conditions. Using the first-order Bridgman equation and the Birch equation of state, the isothermal bulk modulus ( B ₀) was determined to be 162 ± 14 GPa and Young's modulus ( E ) was estimated to be 253 ± 22 GPa assuming a Poisson's ratio for γ-alumina of 0.24 ± 0.2.