Penetration–elimination method for five-axis CNC machining of sculptured surfaces

In this paper, a new tool positioning strategy for five-axis machining, called the penetration–elimination method (PEM), is introduced. The PEM gains from two innovative techniques that can considerably improve the computational efficiency during the calculation of the optimal tool orientations.The first technique includes developing a quantitative definition for the gouging concept and using this definition in conjunction with powerful numerical root-finder algorithms to determine the optimized tool orientations. The second technique dynamically detects the ineffective grid points and drops them from calculations and consequently takes a great role in reducing the computational burden. The ability of the PEM in removing various types of gouging has been shown via several examples. The computational efficiency of the PEM has been compared with another recently described method named the arc-intersect method (AIM). This comparison shows that although the two methods reach the same solution for the tool orientation, the PEM is averagely 7.5 times faster than the AIM.     

Fuzzy-based multiscale edge detection

A new fuzzy-based multiscale edge detection technique is presented. The proposed approach achieves optimal edge detection using the wavelet decomposition of the original signal followed by a novel fuzzy-based decision technique that is applied across the scales. Results indicate a significant improvement in locating edges compared to other multiscale approaches.     

Comparison of DFE and MLSE Receiver Performance on HF Channels

Data communication at rates near or above 2 kbits/s on 3 kHz-baadwidth HF radio channels is subject to impairment from severe linear dispersion, rapid channel time variation, and severe fading. In this investigation, recorded 2.4 kbit/s QPSK signals received from HF channels were processed to extract a time-varying estimate of the channel impulse response. From the estimated channel impulse responses, performance-related parameters were computed for ideal matched filter reception, maximum-likelihood sequence-estimation (MLSE), and decision feedback equalization (DFE). The results indicated that the simpler DFE receiver suffered only a small theoretical performance degradation relative to the more complex MLSE receiver. Other HF channel impulse response statistics were also obtained to shed light on equalization and filter adaptation techniques.     

Health and safety aspects of irrigation of raw-eaten food crops with reused water

The Monterey Wastewater Reclamation Study for Agriculture (MWRSA) has Completed its first year of a five-year pilot effort to investigate and to demonstrate feasibility of food crop irrigation with reclaimed municipal effluent. The project comprises a 96-plot field trial for statistical comparison of three water treatments: an eight-hectare commercial scale farm for demonstration of water reclamation for growing lettuce, broccoli, cauliflower, celery, and artichokes; an aerosol study, a virus assay, market studies, and other ancillary investigations. First year results preliminarily indicate that the main hypothesis of the study will prove to be true, i.e. “raw-eaten food crops irrigated with properly treated municipal wastewater effluent are safe for human consumption”.     

Simulation of a feedback and adaptive systems

A computer approach for simulating a feedback system and its adaptive versions is presented. It is conceived with recursion formulas to describe the interconnected elements of the system. The potential of the approach is explored by applying it to an existing practical system. It is then enhanced by a performance analysis leading to a provision of a unified system evaluation technique. The approach permitted experimentation with different combination of system parameters, system inputs and system configuration. The efficiency of the approach suggets its suitability for a rational engineering design of systems.     

Primary lymphoproliferative disorders of the breast

Primary breast lymphoproliferative disorders are rare lesions and include both the malignant lymphomas and the benign pseudolymphomas. We reviewed 4,491 consecutive cases of breast cancer diagnosed and treated between 1973 and 1988. Patients with lymphoma in other sites and those with lymphomas limited to axillary nodes were excluded. RESULTS. Five patients (0.11%) presented with primary lymphoreticular lesions, of which three were primary non-Hodgkin's lymphoma and two were pseudolymphomas. Patients were followed clinically through to the present time or until death occurred. Surgical procedures included incisional or excisional biopsy in four patients and modified radical mastectomy in one. Two patients received chemo-therapy and one received radiotherapy. One patient with pseudolymphoma subsequently developed infiltrating ductal carcinoma of the same breast. Three patients with primary breast non-Hodgkin's lymphoma died within the follow-up period, with a mean survival of 33 months. CONCLUSIONS. We conclude that primary breast lymphoma is a rare and aggressive breast malignancy with a poor prognosis despite different treatment options.     

Novel Structural Modulation in Ceramic Sensors Via Redox Processing in Gas Buffers

High selectivity, enhanced sensitivity, short response time, and long shelf-life are some of the key features sought in the solid-state ceramic-based chemical sensors. As the sensing mechanism and catalytic activity are predominantly surface-dominated, benign surface features in terms of small grain size, large surface area, high aspect ratio and, open and connected porosity, are required to realize a successful material. In order to incorporate these morphological features, a technique based on rigorous thermodynamic consideration of the metal/metal oxide coexistence is described. By modulating the oxygen partial pressure across the equilibrium M/MO proximity line, formation and growth of new oxide surface on an atomic/submolecular level under conditions of "oxygen deprivation," with exotic morphological features, has been achieved in potential sensor materials. This paper describes the methodology and discusses the results obtained in the case of potential semiconducting ceramic oxide-based carbon monoxide and hydrogen sensors with enhanced characteristics.     

Calcified right ventricular fibroma causing outflow obstruction. Report of a case with successful excision

A 5-year-old boy with clinical findings of pulmonic stenosis was found to have a large calcified mass in the right ventricular outflow region and a gradient of 120 mm Hg between the right ventricle and the pulmonary artery. At surgery, an ovalshaped tumor attached to the interventricular septum and obstructing the right ventricular outflow tract was removed. The child survived and is doing well. Histologically, the tumor had the characteristics of fibroma. A hemodynamic study three months after surgery showed almost complete abolishment of the gradient. To our knowledge this is the fifth reported case of calcified right ventricular fibroma with successful operation. In childhood intracardiac calcifications, together with obstruction, are highly suggestive of this lesion.