CLP(ℜ) and some electrical engineering problems

The Constraint Logic Programming Scheme defines a class of languages designed for programming with constraints using a logic programming approach. These languages are soundly based on a unified framework of formal semantics. In particular, as an instance of this scheme with real arithmetic constraints, the CLP() language facilitates and encourages a concise and declarative style of programming for problems involving a mix of numeric and non-numeric computation.In this paper we illustrate the practical applicability of CLP() with examples of programs to solve electrical engineering problems. This field is particularly rich in problems that are complex and largely numeric, enabling us to demonstrate a number of the unique features of CLP(). A detailed look at some of the more important programming techniques highlights the ability of CLP() to support well-known, powerful techniques from constraint programming. Our thesis is that CLP() is an embodiment of these techniques in a language that is more general, elegant and versatile than the earlier languages, and yet is practical.An earlier version of this paper appeared in the proceedings of the 4th International Conference on Logic Programming, Melbourne, May 1987. Much of this work was carried out while the authors were at Monash University, Melbourne, Australia.     

Peer reviewed: the u.s. Dioxin inventory: are there missing sources?

Some attempts to balance atmospheric emissions of dioxins with deposition have suggested "missing sources." But the evidence disappears in the uncertainties in deposition data.     

A MECHANISM FOR ENHANCING IONIC ACCESSIBILITY INTO SELECTIVE ION EXCHANGE RESINS

ABSTRACT

A bifunctional monophosphonic/sulfonic acid ion exchange resin with high capacity has been synthesized. Metal ion studies have been carried out with europium, americium, and ferric nitrate in solutions of varying acidity, with and without sodium nitrate added. The bifunctional resin complexes far higher levels of Eu(III) from 0.5 and 1 N nitric acid than the monofunctional phosphonic acid resin. It is postulated that the sulfonic acid ligand provides an access mechanism for the metal ions into the polymer matrix by hydrating the matrix and preventing its collapse in high ionic strength solutions thus allowing for rapid ionic complexation by the selective phosphonic acid ligands. The bifunctional monophosphonic/sulfonic acid resin has both ligands bound to a polystyrene support. It complexes higher levels of metal ions than a comparable resin differing only by having the monophosphonic acid ligand directly bound to the C-C backbone. Results are compared to a diphosphonic / sulfonic acid resin.     

The standard potential of the peroxosulphate/sulphate couple

The standard potential of the couple

has been shown to be 1.81 V in aqueous solution at 25°C. This value is much higher than those reported previously, and is consistent with the chemical properties of H₂SO₅ (Caro's acid).     

Radiation characteristics of a high-emissivity cylindrical-spherical cavity with obscuration

We have calculated, to first order, the apparent emissivity of the bounding diffuse surfaces of a high-emissivity cylindrical-spherical cavity enclosure. Our calculations indicate that to achieve emissivities close to a perfectly absorbing blackbody cavity along the bounding surfaces of the spherical enclosure, the radius of the sphere must be equal to or greater than a factor of 4 times the cylinder radius R(S) > or = 4R(C). Furthermore, to achieve emissivities approaching a blackbody cavity along the lower bounding surfaces of the cylindrical enclosure, the length of the cylinder must be a factor of 4 times greater than the radius of the cylinder L > or = 4R(C). In addition, we present the mathematical framework necessary to calculate radiant transfer within a cavity enclosure that contains obscuration. These results can be applied to the design of high-emissivity blackbody calibration cavities and to the reduction of stray light in terrestrial and spaceborne optical systems.     

Electroformed Spray Masks

This paper describes production experience in the manufacture of electroformed spraying and painting masks, this manufacture being carried out as a sideline to the manufacture of hard nickel electro-formed high pressure moulds. The final use of the masks, the masters on which they are electroformed, plating methods and the final engineering problems in finishing the masks are described. The preferred method is to mount a sample moulding on a Perspex base plate, to make the resulting master conductive by silver spraying (twin jet gun, chemical reduction) followed by electrodeposition, first in an acid copper, then in a periodic reverse cyanide copper bath, building up a total thickness of 0·04 in.     

UV resonance Raman probe of heme-bound imidazole established by 15N-labeling of hemoglobin

Recent studies of Cu, Zn superoxide dismutase, and of zinc-finger peptides have established that histidine ligands can be detected in ultraviolet resonance Raman (UVRR) spectra, following NH/D exchange of the imidazole. UVRR spectroscopy therefore offers promise for monitoring histidine ligation in heme proteins. In this work, we characterize heme-bound histidine UVRR bands for N-acetyl-microperoxidase-8 (MP-8) and microperoxidase-11 (MP-11), and also for hemoglobin (Hb). The Hb UVRR spectra are dominated by tyrosine and tryptophan contributions, but a band appears at 1340 cm⁻¹ in D₂O solution, which is assigned to a mode of Fe-bound imidazole. This band shifted 24 cm⁻¹ in protein which was labeled with ¹⁵N via expression of the Hb gene in E. coli grown on ¹⁵NH₄⁺. In MP-11, the position of this band is insensitive to ligation or oxidation state changes, but it is 2 cm⁻¹ lower in deoxyHb than in the CO adduct. This shift may reflect mechanical forces on the proximal histidine in the T state, and/or changes in its H-bonding.     

ION-SELECTIVE POLYMER-SUPPORTED REAGENTS

ABSTRACT

The design and synthesis of polymer-supported reagents that can selectively complex targeted metal ions from multi-component solutions will continue to be an important area of research into the 21^st century. Environmental remediation and sensor technology are only two of a number of areas in which such polymers can be applied. This paper reviews the recent literature with an emphasis on the key ligands that have been immobilized in order to better understand where this research is heading in the near future.     

POLYMER-SUPPORTED REAGENTS FOR MOLECULAR SEPARATIONS

A Hammett study of the complexing abilities of various polymer-supported reagents for phenols, anilines, and benzoic acids is described. For each polymeric reagent, the percent absorbed of each family of compounds is correlated with the Hammett substituent constants. A carboxylic acid resin shows no interaction with phenols and benzoic acids; only a weak interaction with anilines is found since 25% of each is absorbed regardless of the substituent present on the aromatic ring. This contrasts with the strong interaction displayed by the sulfonic resin and the moderate interaction of the phosphinic resin. Phosphonic and phosphonate monoester resins absorb increasing amounts of anilines as their basicity increases. The purely coordinating- phosphonate diester resin absorbs uniformly low levels of the three families of compounds with no substituent effect on the percent absorbed. The sulfonic resin quantitatively absorbs the anilines within the temperature range 6 to 40 C while the phosphinic resin absorbs decreasing levels within the same range. The phosphinic resin is more selective than the sulfonic resin under competitive conditions     

Longitudinal findings from the normative aging study: I. Does mental health change with age?

Longitudinal changes in self-reported symptoms were investigated using the Cornell Medical Index (CMI) in a sample of 2,041 men. The average man completed 5 CMIs (range?=?2–8) over 17 (range?=?2–25) years. Using a two-stage growth model, we first regressed symptoms against time on study for each man. The average slope of physical symptoms showed a moderate increase over time, but the average slope of psychological symptoms showed little change. Next individual differences in change were examined using age at entry as an explanatory variable. Age accounted for 50% of the variance in physical symptoms at entry and 7% of the variance in slopes, but explained neither baseline level nor change in psychological symptoms. Rather, a U-shaped curve described the relation between age and psychological symptom change. These results, in concert with a developmental perspective, may help reconcile conflicting findings on aging and mental health. (PsycINFO Database Record (c) 2010 APA, all rights reserved)