53 research outputs found
Sensitivity analysis of the add-on price estimate for the edge-defined film-fed growth process
The analysis is in terms of cost parameters and production parameters. The cost parameters include equipment, space, direct labor, materials, and utilities. The production parameters include growth rate, process yield, and duty cycle. A computer program was developed specifically to do the sensitivity analysis
Advanced Czochralski silicon growth technology for photovoltaic modules
Several economic analyses had indicated that large-diameter, multiple ingot growth using a single crucible with melt replenishment would be required for Cz growth to be economically viable. Based on the results of these analyses, two liquid and two solid feed melt replenishment approaches were initiated. The sequential solid feed melt replenishment approach, which demonstrated elements of technical feasibility is described in detail in this paper. Growth results of multiple ingots (10-cm-diameter, totaling 100 kg; and 15-cm-diameter, totaling 150 kg weight per crucible) are presented. Solar cells were fabricated and analyzed to evaluate the effects of structure and chemical purities as a result of multiple growth. The results indicate that, with semiconductor-grade silicon, feedstock impurity build-up does not seem to degrade cell performance. For polycrystalline cells, the average efficiencies are 15 to 25% lower than those of single crystalline cells. Concerns regarding single crystal yields, crucible quality and growth speed are indicated, and present status and future research thrusts are also discussed
Cost of Czochralski wafers as a function of diameter
The impact of diameter in the range of 10 to 15 cm on the cost of wafers sliced from Czochralski ingots was analyzed. Increasing silicon waste and decreasing ingot cost with increasing ingot size were estimated along with projected costs. Results indicate a small but continuous decrease in sheet cost with increasing ingot size in this size range. Sheet costs including silicon are projected to be 60/sq m (1980 $) depending upon technique used
Computed tomography guided laser ablation of osteoid osteoma: a study of 30 cases
Background: Osteoid osteoma (OO) is a benign but painful bone lesion that primarily occurs in children and young adults 1. Male:Female ratio is 3:1. The aim of the study was to present our experience of CT guided LASER ablation of radiologicaly proven Osteoid osteomas in the various bones.Methods: Over the period of 5 years 30 cases of osteoid osteomas in various bones diagnosed on various modalities were treated by CT guided LASER ablation. Bone wise distribution of cases was spine (3), upper end of femur (11), lower end of femur (6), upper end of tibia (4), upper end of humerus (3), lower end of radius (2) and calcaneum (1). 22 patients were treated under spinal and regional anesthesia and 8 patients were treated under short general anesthesia. All the patients were treated on day care basis. The LASER fiber was inserted in the nidus under CT guidance through bone biopsy needle and 1800 joules energy delivered in the lesion continuous mode.Results: 29 (96%) patients have complete relief of pain in twenty-four hours after LASER ablation, One week after treatment all 30 patients were pain free. No neurologic complication was observed in any of our patients with spinal osteoid osteomas.Conclusions: CT guided LASER ablation is a safe, simple and effective method of treatment for osteoid osteoma
Performance up gradation of static VAR compensator with thyristor binary switched capacitor and reactor using model reference adaptive controller
There are various static var compensator configurations are available and listed in the literature. Their performances are evaluated based on their voltage support, dynamic response, losses, cost, and additional filter requirement, if any. In this paper, efforts are made to improve the dynamic performance parameter such as rise time, settling time, and peak overshoots. A new topology with an adaptive controller is presented, in which capacitor and reactor banks are divided in their binary values and connected in the shunt. Capacitor and reactor banks are operated by thyristorised switches. Both these banks are operated in closed-loop form as a cascade control. Amongst these, capacitor bank operates as coarse control, and reactor bank acts as fine control. For the performance enhancement, a model reference adaptive controller is used. The system identification toolbox is used to evaluate the mathematical model of the plant with Matlab. The model\u27s performance was analyzed deeply by the adaptive controller with different reference models such as critical, under, and overdamped. The performance parameters such as rise time, settling time, and peak overshoot in the form of reactive power swings, are evaluated and plotted for different adaptive gains using MIT rules
New 2,6,9-trisubstituted adenines as adenosine receptor antagonists: a preliminary SAR profile
A new series of 2,6,9-trisubstituted adenines (5–14) have been prepared and evaluated in radioligand binding studies for their affinity at the human A1, A2A and A3 adenosine receptors and in adenylyl cyclase experiments for their potency at the human A2B subtype. From this preliminary study the conclusion can be drawn that introduction of bulky chains at the N6 position of 9-propyladenine significantly increased binding affinity at the human A1 and A3 adenosine receptors, while the presence of a chlorine atom at the 2 position resulted in a not univocal effect, depending on the receptor subtype and/or on the substituent present in the N6 position. However, in all cases, the presence in the 2 position of a chlorine atom favoured the interaction with the A2A subtype. These results demonstrated that, although the synthesized compounds were found to be quite inactive at the human A2B subtype, adenine is a useful template for further development of simplified adenosine receptor antagonists with distinct receptor selectivity profiles
The Short-Term Effect of Weight Loss Surgery on Volumetric Breast Density and Fibroglandular Volume
Purpose:
Obesity and breast density are both associated with an increased risk of breast cancer and are potentially modifiable. Weight loss surgery (WLS) causes a significant reduction in the amount of body fat and a decrease in breast cancer risk. The effect of WLS on breast density and its components has not been documented. Here, we analyze the impact of WLS on volumetric breast density (VBD) and on each of its components (fibroglandular volume and breast volume) by using three-dimensional methods.
Materials and Methods:
Fibroglandular volume, breast volume, and their ratio, the VBD, were calculated from mammograms before and after WLS by using Volparaâ„¢ automated software.
Results:
For the 80 women included, average body mass index decreased from 46.0 ± 7.22 to 33.7 ± 7.06 kg/m2. Mammograms were performed on average 11.6 ± 9.4 months before and 10.1 ± 7 months after WLS. There was a significant reduction in average breast volume (39.4 % decrease) and average fibroglandular volume (15.5 % decrease), and thus, the average VBD increased from 5.15 to 7.87 % (p < 1 × 10−9) after WLS. When stratified by menopausal status and diabetic status, VBD increased significantly in all groups but only perimenopausal and postmenopausal women and non-diabetics experienced a significant reduction in fibroglandular volume.
Conclusions:
Breast volume and fibroglandular volume decreased, and VBD increased following WLS, with the most significant change observed in postmenopausal women and non-diabetics. Further studies are warranted to determine how physical and biological alterations in breast density components after WLS may impact breast cancer risk.ECU Open Access Publishing Support Fun
Assessment of Health Care Cost for Complex Surgical Patients: Review of Cost, Re-Imbursement and Revenue Involved in Pancreatic Surgery at a High-Volume Academic Medical Centre
AbstractBackgroundPancreatic surgery is complex with the potential for costly hospitalization.MethodsA retrospective review of patients undergoing a pancreatic resection was performed.ResultsThe median age of the study population was 64 years. Half of the cohort was female (51%), and the majority were white (62%). Most patients underwent a pancreaticoduodenectomy (PD) (69%). The pre-operative age-adjusted Charlson comorbidity index was zero for 36% (n = 50), 1 for 31% (n = 43) and ≥2 for 33% (n = 45). The Clavien–Dindo grading system for post-operative complication was grade I in 17% (n = 24), whereas 45% (n = 62) were higher grades. The medians direct fixed, direct variable, fixed indirect and total costs were 15 397, 31 631, respectively. There was a positive contribution margin of 6790. On univariate analyses, age, type of operation and complication grade were associated with total cost (P ≤ 0.05), whereas operation type and complication grade were associated with a net margin (P = 0.01). These findings remained significant on multivariate analysis (P < 0.05).ConclusionsIncreased cost, reimbursement and revenue were associated with type of operation and post-operative complications
A Self-Bracketing Search Technique for the Classical Dispersion Analysis of Infrared Reflectance Data
Smart Wireless Sensor Network For Smart Home
System controls and monitoring has become a need in our households due to increase in use of modern applications and devices such as smart home security systems like CCTVs, E-lock systems, also other various appliances like smart lights, fans, air conditioners etc. The current solution for this is the smart wireless sensor network. This network use various monitoring setups like night visions, cameras, and infrared lasers. Also some are even designed to study the behavior pattern of the user and function accordingly. Electricity control of a building can be handled effectively with the help of sensor network. Such networks can be integrated in buildings, offices, homes for energy harvesting also its storage which can be used for the electronic components and circuit. The network can also be beneficial for the betterment of the living conditions of the home inhabitants by having a constant survelance for elderly and young children. As the system of networks is completely automated it reduces the human error and reduces energy consumption by optimizing it perfectly. Newer self-maintaining sensor networks can even enhance the security infrastructure of a home, office or an institute. This study further elobrate the functioning and uses of wireless sensor networks
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