Geometric Modeling Approaches for Civil Engineering and Building Design

Abstract: The paper examines constraint strategies appropriate for modeling three-dimensional geometry in civil engineering design. Despite potential advantages, computer based geometric models are seldom used from the early stages of design since they are difficult to modify; this is because conventional models describe the results of design decisions rather than the intent. To support powerful modification operations, a model must incorporate constraints describing geometric intent; this allows geometric modifications to be propagated through an assembly so that the constraints are maintained. During the past decade, there has been significant research in geometric constraints. The paper reviews this research and identifies three basic constraint approaches: (1) the algebraic approach, which represents constraints as equations; (2) the deductive approach, which represents constraints as logical predicates; and (3) the constructive approach, which represents constraints as geometric operations. Since much of this research is oriented toward machine design, the paper compares modeling issues in machine design and civil engineering design in order to identify important research areas. These areas include the following two aspects of constraint organization: (1) hierarchical constraints, creating and manipulating constraints in meaningful groups; and (2) assembly constraints, defining constraints on the overall geometry of an assembly.     

Quantitation of Ink Transferred During Pharmaceutical Printing Operations Using Inductively Coupled Plasma Atomic Emission Spectroscopy

The identification of solid dosage forms is often achieved through printing with a non-toxic ink. Due to product purity requirements, a method to quantify the amount of ink applied to tablets and capsules is of interest to the pharmaceutical industry.

The following presentation investigated the use of inductively coupled plasma atomic emission spectroscopy (ICP-AES) as a direct method of quantifying the amount of ink on a tablet. Because the ink used contained an iron oxide pigment of known composition, quantitation of the iron content could be used to measure the amount of ink transferred to the tablet.

The quantitative results obtained using ICP-AES were in agreement with calculated values for the volume of ink in the gravure roll. Tablets exposed to “double printing” were easily detected by the ICP-AES method.     

Analysis of lipidation of recombinant Lyme vaccine protein (rOspA) by electrospray mass spectroscopy

Lipidation at the N-terminal of recombinant outer surface protein A (rOspA) is an important determinant of its immunogenicity. Lipidation patterns of rOspA can be sensitive to processing environments and storage conditions. In order to assure product consistency and stability. it is essential to characterize and monitor lipidation patterns of rOspA through its life-cycle. Electrospray mass spectroscopy combined with maximum entropy calculation was employed to analyze the lipidation of rOspA. The results revealed that more than 90% of protein is a tri-lipidated rOspA and the remainder is di-lipidated. It was demonstrated that the method is both sensitive and quantitative and has the potential to be used for routine quality control and stability testing.     

Binding constants in the formation of mammalian protein synthesis initiation complexes and the role of mRNA

Acute idiopathic thrombocytopaenic purpura is the most common of the thrombocytopaenias of childhood. Clinically it is associated with petechiae, mucocutaneous bleeding and occasionally haemorrhage into tissues. The oral mucosa is frequently involved. This paper describes a case presenting in general dental practice.     

Laser Doppler flowmetry during open reduction for developmental dysplasia of the hip

Laser Doppler flowmetry was used intraoperatively to monitor femoral head perfusion during open reduction of 13 congenital hip dislocations in 11 patients. Laser Doppler determinations ranged from 12 to 400 mV before reduction and 30 to 300 mV after reduction. Three patients had magnitude changes in excess of 50%. One had increased perfusion, and two had decreased blood flow. Avascular necrosis of the hip occurred in one patient that was not predicted by laser Doppler flowmetry. Femoral head perfusion measured 175 mV for the dislocated hip and 180 mV after reduction of the femoral head and completion of the pelvic osteotomy. The authors conclude that laser Doppler flowmetry is not a reliable method for monitoring femoral head perfusion during open reduction of the hip for developmental hip dysplasia.     

Attitudes toward service use among wife caregivers of frail older veterans

This study investigated (a) attitudes toward service use among wife caregivers of frail older veterans; and (b) the relationship between those attitudes and service utilization by the wives. The study focused on three sets of attitudinal variables: attitudes towards various kinds of dependencies; individual and family ethos concerning service use; and perceptions of responsibility for care. Respondents were 80 wife caregivers of frail older (age 55+) veterans at a Department of Veterans Affairs Medical Center in a Midwestern state. Most caregivers agreed that it is acceptable to get help with the physical care of the husband and to get help themselves for the emotional strains caused by caregiving. Acceptability of a wife's getting help with the physical care of her husband was a positive predictor of number of services ever used and frequency of in-home service use. Wives' view that help from outside agencies should be used only as a last resort was the strongest and most consistent negative predictor of both number of services ever used and frequency of service use.