Ender nailing of acute humeral shaft fractures in multiple injuries

From January 1987 to April 1993, 25 multiply injured patients were treated with closed intramedullary Ender nail fixation of the humeral shaft. Criteria for the procedure were humeral diaphyseal fractures with associated multiple injuries. Seventeen distal and mid-shaft fractures were treated via a modified anterograde approach in which the rotator cuff is not violated. Eight proximal third fractures were treated via the standard retrograde approach. Postoperative follow-up averaged 36 months. Full range of motion was attained 17 of the 25 patients. Of the eight remaining patients, three with a slightly limited range of motion achieved full range of motion following nail removal; three had preoperative radial nerve palsy which resolved within 1 year, and two patients required follow-on plating. In 92 per cent (23 of 25) there were no incidences of infection or non-union. Flexible nails avoid complications of reaming. The modified anterograde approach allows excellent shoulder motion since it does not violate the rotator cuff. Ender nails provide excellent fixation and clinical outcome in the multiply injured patient and are cost effective compared with interlocking nails.     

Evaluating the learning process of mechanical CAD students

There is little theoretical or experimental research on how beginner-level trainees learn CAD skills in formal training sessions. This work presents findings on how trainees develop their skills in utilizing a solid mechanical CAD tool (Pro/Engineer version 2000i² and later version Wildfire). Exercises at the beginner and intermediate levels were designed so that several variations of a solid object are built by non-experienced trainees as they accumulate training time. In this case, trainees are fourth year mechanical engineering seniors and as such, they were of a similar technical and gender make-up. This assessment was conducted over the duration of training (16-week long semester). The test exercises were used to assess the trainees’ speed and proficiency in the use of CAD by (1) measuring their performance time and (2) feature count (number of features-of-size used to build the test parts). Using performance time data, empirical learning curves are generated. Breaking these curves into declarative and procedural components provides insight into how fast the trainees develop cognitive and motor CAD skills. In order to confirm that this methodology can be extended to other CAD platforms, a follow-up study was performed on a different set of beginner-level trainees with similar make-up while using the same beginner-level parts but with a more recent version of Pro/Engineer: Wildfire. One significant result of this study is that the procedural and declarative components of CAD learning are largely cognitive.     

Comparison of optimum tapered cascade and optimal square cascade for separation of xenon isotopes using enhanced TLBO algorithm

The present study is conducted to propose a new code for optimizing a multicomponent isotope separation cascade. An efficient code is developed using an enhanced TLBO algorithm with a novel mutation for calculating the optimal parameters. The results indicate that by implementing a new objective function derived from the combination of D function with total interstage flow rates, the optimum tapered cascade is more efficient than the optimal square one. Also, the best feed locations for the separation of the middle components in the square cascade are the middle stages.     

Incorporating human factors in order picking planning models: framework and research opportunities

Order picking (OP) activities, essential to logistics operations, are laborious and time-intensive. Humans are central actors in the OP process and determine both OP effectiveness and efficiency. Many researchers have developed models for planning OP activities and increasing the efficiencies of such systems by suggesting different warehouse layouts, OP routes or storage assignments. These studies have, however, ignored workers’ characteristics, or human factors, suggesting that they cannot be substantiated, which led to only partially realistic results. This paper proposes a conceptual framework for integrating human factors into planning models of OP activities and hypothesises that doing so improves the performance of an OP system and workers’ welfare. The framework is based on a systematic literature review that synthesises findings documented in the OP and human factors literature. The results of the paper may assist researchers and practitioners in designing OP systems by developing planning models that help in enhancing performance and reducing long-term costs caused by work-related inefficiencies.     

Exploring the Design and Spectroscopic Characteristics of PVA/Si3N4/SiBr4 New Structures for Electronics and Optics Devices

Silicon - This work aims to design of silicon nitride (Si3N4) and silicon bromide (SiBr4) doped polyvinyl alcohol (PVA) as promising semiconductors materials which can be used in various...     

Intumescent flame retardant polyurethane/starch composites: Thermal,mechanical, and rheological properties

Intumescent flame retardant polyurethane/starch (IFRPU/starch) composites were prepared by means of melt blending. Microencapsulated ammonium polyphosphate (MCAPP) was added to improve its compatibility with matrix, retardation of reaction between acid and carbon source, and its water resistancy. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of hydrogen bonding and entangled network between IFR system and PU matrix. Further, scanning electron microscopy (SEM) illustrated homogeneity of starch in matrix. By addition of 10 wt % of starch and 20 wt % of IFR, limiting oxygen index (LOI) increased from 22.0 to 40.0 and UL94 V0 rating was achieved. Differential scanning calorimetry (DSC) detected three endothermic transitions and one glass transition (T_g). The temperature of transition III and T_g increased with starch due to crosslinking between PU and starch. The improved thermal stability in the presence of starch was confirmed by thermogravimetric analysis (TGA). Beside the fact that starch was used as a carbonization agent to improve flame retardancy, it also effectively led to enhanced mechanical and viscoelastic properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41158.