Integrative and multi-disciplinary framework for the 3D rehabilitation of large mandibular defects

The International Journal of Advanced Manufacturing Technology - The restoration of mandibular defects, especially large deformities is regarded as the most challenging surgical procedure owing to...     

A selective organosilica membrane for ethyl acetate dehydration by pervaporation

Organosilica bis(triethoxysilyl) ethane (BTESE) membranes were explored for pervaporation dehydration of binary and ternary mixtures of ethyl acetate (EA) by undiluted sol coating combined with flash firing. Three BTESE membranes (M1, M2, and M3) were fabricated on macroporous supports by varying BTESE concentrations (0.5, 2.5, and 5 wt% BTESE, respectively) in polymer sols. The membranes were characterized by DLS, SEM, FTIR, XRD, contact angle, AFM, and pervaporation performance to discuss the effect of the BTESE contents in the polymer sol on the formation and dehydration performance of resulting organosilica membranes. It was found that 5 wt% loading of BTESE led to a highly selective membrane for dehydration of EA/H₂O mixture. Among the synthesized membranes, M3 delivered flux of 0.84 ± 0.05 kg.m⁻².h⁻¹ with a selectivity of >10,000 for EA/H₂O mixture (98/2 wt%) at 60°C. The time course of pervaporation dehydration for the EA/H₂O mixture (95/5 wt%) confirms the stability of BTESE membrane in the investigated time period of 120 h. Further, the membrane exhibited excellent selectivity larger than 10,000 for separation of ternary mixtures (90/2/8 wt%) of ethyl acetate/ethanol/water and n-propyl acetate/isopropanol/water respectively, the composition of which is similar to the top product of the distillation column used in the industrial esterification process. The best separation performance and excellent acid stability of BTESE membranes in this study suggest that the simple synthesis protocol of undiluted sol coating and flash firing will provide a cost-effective, quick, and efficient synthesis route for practical membrane based applications.     

Analyzing and automatically labelling the types of user issues that are raised in mobile app reviews

Mobile app reviews by users contain a wealth of information on the issues that users are experiencing. For example, a review might contain a feature request, a bug report, and/or a privacy complaint. Developers, users and app store owners (e.g. Apple, Blackberry, Google, Microsoft) can benefit from a better understanding of these issues – developers can better understand users’ concerns, app store owners can spot anomalous apps, and users can compare similar apps to decide which ones to download or purchase. However, user reviews are not labelled, e.g. we do not know which types of issues are raised in a review. Hence, one must sift through potentially thousands of reviews with slang and abbreviations to understand the various types of issues. Moreover, the unstructured and informal nature of reviews complicates the automated labelling of such reviews. In this paper, we study the multi-labelled nature of reviews from 20 mobile apps in the Google Play Store and Apple App Store. We find that up to 30 % of the reviews raise various types of issues in a single review (e.g. a review might contain a feature request and a bug report). We then propose an approach that can automatically assign multiple labels to reviews based on the raised issues with a precision of 66 % and recall of 65 %. Finally, we apply our approach to address three proof-of-concept analytics use case scenarios: (i) we compare competing apps to assist developers and users, (ii) we provide an overview of 601,221 reviews from 12,000 apps in the Google Play Store to assist app store owners and developers and (iii) we detect anomalous apps in the Google Play Store to assist app store owners and users.     

DEA window analysis and Malmquist index to assess energy efficiency and productivity in Jordanian industrial sector

This research evaluates the energy efficiency and productivity growth in the industrial sector over the period of 1999 till 2013 using data envelopment analysis (DEA). Two cases are analyzed; in the first case (GVA), the output is the gross value added, whereas two outputs are considered in the second case (GCO), CO₂ emission and GVA. Five key input factors are considered in both cases. From DEA window analysis, the technical inefficiency (TIE) values are zeros in windows (2001–2005) till (2003–2007), (2007–2011), and (2008–2012), whereas the pure technical inefficiency (PTIE) values are zeros in windows (1999–2003) till (2003–2007). Finally, the scale inefficiency (SIE) values are zeros in windows (2001–2005) till (2003–2007). These results help policy planners on how to better utilize resources and management efficiency over time and guide operational managers when to increase or decrease the scale. Moreover, the averages of inefficiency values in the GVA case are smaller than their corresponding in the GCO case, which indicates the negative effect of CO₂ emission on efficiency. Further, Malmquist index is estimated for three 5-year energy plans. The productivity index is found less than one for the third plan (2009–2013), which indicates a decrease productivity growth. In conclusions, research results provide valuable support when assessing the progress of energy efficiency and productivity in industrial sector.     

Formulation and release of doxycycline HCL from an ion activated in situ gelling delivery system for the treatment of periodontal disease

This study reports on the formulation of doxycycline HCL in an ion activated in situ gelling delivery system and its implications for the treatment of periodontal disease. The system is based on the use of alginate as the gelling agent and hydroxypropyl methylcellulose (HPMC) as a viscosity enhancing agent. The ion activated gelling mechanism in this system is based on the concept of interaction with the divalent calcium ions present in the gingival crevicular fluid (GCF). The gelling capacity of the prepared formulations was assessed visually and by investigating their rheological behavior upon mixing with human blood serum since it has the same composition as the GCF. The rheological behavior of all formulations was not affected by incorporation of the drug. In vitro release studies showed that the alginate/HPMC mixture, upon gelling after mixing with serum, can sustain the release of doxycycline HCL for an extended period of time which was more than 12 days. These results indicated that this system can be used as an in situ gelling local delivery system for the treatment of periodontal disease. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Sustained release of tetracycline from polymeric periodontal inserts prepared by extrusion

The specific aim of this study was to prepare polymeric inserts containing tetracycline that are intended for intraperiodontal pocket application. The inserts were prepared by a simple extrusion method and based on mixtures of polyvinyl alcohol, glyceryl behenate, xanthan gum, carrageenan, hydroxypropyl methylcellulose, and hyaluronic acid in addition to tetracycline HCL. The inserts were characterized regarding average weight, diameter, water content, and average tetracycline content. Zero‐order release kinetics of tetracycline were observed in case of three of the four batches of the prepared inserts with release profiles that were essentially similar. The release of the drug was incomplete in all cases. This was due, as shown by the equilibrium dialysis tests, to tetracycline binding by the polymers. However, the inserts performed more than 7 days drug sustained release which indicates promising results for local delivery of tetracycline for treatment of periodontal disease. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Performance of Primary Users in Spectrum Sharing Cognitive Radio Environment

This paper investigates the performance of the primary user in a multiuser cognitive radio environment. Using spectrum sharing method, multiple cognitive users compete to share a channel dedicated to the primary user in order to transmit their data to a common receiver unit. Only one cognitive user is scheduled to share the channel, and to do so, its transmit power should not increase the primary user’s outage probability above a certain limit. The average bit error rate and the average channel capacity of the primary user are derived in this setup for different cognitive scheduling schemes. The performance measures of the primary user are found to depend on the cognitive user’s scheduling criterion and on the parameters of the communication environment.     

Analyzing and enhancing the parallel sort operation on multithreaded architectures

The sort operation is a core part of many critical applications (e.g., database management systems). Despite the large efforts to parallelize it, the fact that it suffers from high data-dependencies vastly limits its performance. Multithreaded architectures are emerging as the most demanding technology in leading-edge processors. These architectures include simultaneous multithreading, chip multiprocessors, and machines combining different multithreading technologies. In this paper, we analyze the memory behavior and improve the performance of the most recent parallel radix and quick integer sort algorithms on modern multithreaded architectures. We achieve speedups up to 4.69× for radix sort and up to 4.17× for quicksort on a machine with 4 multithreaded processors compared to single threaded versions, respectively. We find that since radix sort is CPU-intensive, it exhibits better results on chip multiprocessors where multiple CPUs are available. While quicksort is accomplishing speedups on all types of multithreading processers due to its ability to overlap memory miss latencies with other useful processing.