Scale periodicity and its sampling theorem

The scalar transform is a new representation for signals, offering a perspective that is different from the Fourier transform. We introduce the notion of a scalar periodic function. These functions are then represented through the discrete scale series. We also define the notion of a strictly scale-limited signal. Analogous to the Shannon interpolation formula, we show that such signals can be exactly reconstructed from exponentially spaced samples of the signal in the time domain. As an interesting, practical application, we show how properties unique to the scale transform make it very useful in computing depth maps of a scene     

The integration of process and geometry within an open architecture machine tool controller

The authors discuss in detail the anticipated future requirements of an advanced control for metal cutting machine tools; of particular interest is the integration of process monitoring and optimization with the normal processes of interpolation and axis control. A detailed discussion of the philosophy underlying the development of the UBC open architecture machine tool controller and its current capabilities is also presented.     

A thrombolytic decision tree.

We constructed a decision analysis model based on data in the medical literature to estimate the possible outcomes of thrombolytic therapy in patients 50 to 80 years old with possible myocardial infarction. We used the model to test the most likely effects of treatment (determined by averaging the values in reports of large studies) and the worst effects reported so far. The program begins by asking the patient's age, the hours from the onset of pain, and the probability of acute myocardial infarction. It then provides an opportunity to perform sensitivity analyses by changing the values for these variables and for the probability of death in the absence of thrombolytic therapy, as well as for the probability of major stroke and hemorrhage. The counterintuitive findings observed with this program are that the benefits of thrombolytic therapy increase with age and that young patients derive surprisingly little benefit from it.     

Management of the patient with minor traumatic brain injury

Staff in the accident and emergency department and critical care unit are often confronted with patients who have sustained life-threatening injuries. In such situations the symptoms of a minor traumatic brain injury (MTBI) may be missed. It is important that, when the physical symptoms begin to subside, nurses are aware of the symptoms of MTBI and respond accordingly. A post-concussion syndrome may develop 2 weeks to 2 months after a MTBI. This syndrome can affect the patient's ability to perform the usual activities of living. This article defines MTBI, describes the symptoms encountered in patients with MTBI, and outlines the pathophysiology, clinical findings, treatment and nursing interventions.     

An experimental investigation of triboelectrification in cohesive and non-cohesive pharmaceutical powders

A detailed experimental investigation has been undertaken of the triboelectrification process of the pharmaceutical excipient alpha-lactose monohydrate and selected drugs. Particle charge studies involved the design and construction of an apparatus to incorporate pneumatic powder feed, triboelectric charging via a cyclone separator and simultaneous powder charge (Q) and mass (M) measurements using a modified Faraday well. Preliminary studies showed the charging of the selected materials to be unaffected by relative humidity up to 84%, due to the very low hygroscopicity of the powders. Experiments using lactose size fractions with brass, steel and cellulose contact charging surfaces conducted at different feeder gas pressures, gave net electronegative specific charge values (Q/M) for the metal surfaces, and electropositive values for cellulose. Specific charge increased linearly with gas pressure for the metals, and non-linearly for cellulose. Samples of micronised lactose and beclomethasone dipropionate (BDP) showed more tendency than unmicronised samples to adhere to the contact surface which resulted in more complex charging processes. A novel system to analyse the charge and mass data in further detail was developed, giving relative Q/M values at unit time intervals. It is proposed that this will overcome the limitations of reliance on the final net specific charge value. Preliminary results indicated differences in the charging mechanism for lactose in contact with the two metal surfaces.