A rubber-modified thermoplastic where the morphology produced by phase-separation induced by polymerization disappears at high conversions

An unexpected experimental finding is reported where the primary morphology developed during polymerization-induced phase separation in a rubber-modified thermoplastic practically disappears at high conversions. This process was evidenced by light scattering (LS) and scanning electron microscopy (SEM) for a particular composition of solutions of polyisobutylene oligomers (PIB) in isobornylmethacrylate (IBoMA), during the free-radical polymerization of the monomer. The primary phase separation produced a dispersion of domains rich in PIB containing significant amounts of the monomer (IBoMA). Polymerization of the monomer in these domains occurred at high overall conversions producing the filling of dispersed domains with a PIBoMA-PIB blend that could not be distinguished from the matrix. Under these conditions the final material had the appearance of a homogeneous blend.     

Inverse Analysis of Impact Test Data: Experimental Study on Polymeric Materials Displaying Brittle Behaviour

This paper deals with the influence of the testing equipment on impact load measurements. A previously developed method of analysis and processing of the experimental data based on a refined analogical model of the impact event and inverse problem techniques is used. This method makes it possible to obtain the mechanical response of the material, notwithstanding the disturbance of the dynamic effects associated to the test. Results from tests carried out both on falling weight and swing pendulum instrumented testing machines are compared. It is shown that this method can give an accurate estimation of the actual bending force in impact testing independent of the testing equipment.     

The Utility of Nasal Challenges to Phenotype Asthma Patients

Asthma is a heterogeneous disease in terms of both phenotype and response to therapy. Therefore, there is a great need for clinically applicable tools allowing for improved patient classification, and selection for specific management approaches. Some interventions are highly helpful in selected patients (e.g., allergen immunotherapy or aspirin desensitization), but they are costly and/or difficult to implement. Currently available biomarkers measurable in peripheral blood or exhaled air display many limitations for asthma phenotyping and cannot identify properly the specific triggers of the disease (e.g., aeroallergens or NSAID). The united airway concept illustrates the relevant epidemiological and pathophysiological links between the upper and lower airways. This concept has been largely applied to patient management and treatment, but its diagnostic implications have been less often explored. Of note, a recent document by the European Academy of Allergy and Clinical Immunology proposes the use of nasal allergen challenge to confirm the diagnosis of allergic asthma. Similarly, the nasal challenge with lysine acetylsalicylate (L-ASA) can be used to identify aspirin-sensitive asthma patients. In this review, we will summarize the main features of allergic asthma and aspirin-exacerbated respiratory disease and will discuss the methodology of nasal allergen and L-ASA challenges with a focus on their capacity to phenotype the inflammatory disease affecting both the upper and lower airways.     

Collective intelligence as mechanism of medical diagnosis: The iPixel approach

Collective intelligence (CI) is an active field of research, which capitalizes the knowledge of human collectives in order to create, to innovate and to invent. There are two important mechanisms to implement CI: recommender and reputation systems. Recommender systems are used to provide filtered information from a large amount of elements. The recommendations are intended to provide interesting elements to users. Recommendation systems can be developed using different techniques and algorithms where the selection of these techniques depends on the area in which they will be applied. This work presents iPixel Recommender Engine, which is focused on the medical field. iPixel Recommendation Engine supports the process of differential diagnosis by recommending mammographic evaluations. Each mammogram is collectively tagged by the users’ community with a semantic sense; this feature allows iPixel acquires collective knowledge. iPixel can associate more than one feature with each mammogram. This work also presents a qualitative evaluation, where the basic features that a recommendation system should have in the medical field were obtained. Finally, a comparison was carried out with other similar recommender systems in order to know the Pixel advantages.     

Basic actions to improve energy efficiency in commercial buildings in operation

Numerous studies have focused on improving energy efficiency in commercial buildings. Engineers and researchers have developed complex methods to improve energy efficiency, but buildings are often managed by non-specialised technicians who need understandable and cost-effective actions to implement in their buildings. This paper presents basic actions on which to base improvements in energy efficiency in commercial buildings in operation. Furthermore, obtained results and details of the implementation of these techniques in various buildings in the Universitat Politècnica de València are presented.     

Small-scale experiments of self-sustaining decomposition of NPK fertilizer and application to events aboard the Ostedijk in 2007

Small-scale experiments to investigate the self-sustaining decomposition (SSD) behaviour of NPK 16.16.16 fertilizer have been undertaken. These experiments show that this material will undergo self-sustaining decomposition and are used to give insight into the behaviour of the reaction. A three-step decomposition process is observed leading to a self-sustained reaction reaching temperatures of 200–350 °C. The measured heat of reaction is 0.73–1.8 MJ/kg. Measurements are applied to the events that occurred aboard the ship Ostedijk in 2007 in which a SSD reaction occurred. The mass loss rate from the cargo was calculated to range from 0.5 kg/s on the first day to 12 kg/s on the last day. From this measurement, the maximum fire size was estimated to be in the range 5.8–29 MW.     

Compact Modules for Wireless Communication Systems in the E-Band (71–76 GHz)

The millimeter-wave spectrum above 70 GHz provides a cost-effective solution to increase the wireless communications data rates by increasing the carrier wave frequencies. We report on the development of two key components of a wireless transmission system, a high-speed photodiode (HS-PD) and a Schottky Barrier Diode (SBD). Both components operate uncooled, a key issue in the development of compact modules. On the transmitter side, an improved design of the HS-PD allows it to deliver an output RF power exceeding 0 dBm (1 mW). On the receiver side, we present the design process and achieved results on the development of a compact direct envelope detection receiver based on a quasi-optical SDB module. Different resonant (meander dipole) and broadband (Log-Spiral and Log-Periodic) planar antenna solutions are designed, matching the antenna and Schottky diode impedances at high frequency. Impedance matching at baseband is also provided by means of an impedance transition to a 50 Ohm output. From this comparison, we demonstrate the excellent performance of the broadband antennas over the entire E-band by setting up a short-range wireless link transmitting a 1 Gbps data signal.     

Influence of the density of states on the open-circuit voltage in small-molecule solar cells

Open-circuit voltages are strongly dependent on the density-of-states in solar cells based on disordered semiconductors. In this work, organic solar cells based on tetraphenyldibenzoperiflanthene and fullerene C₇₀ with a bilayer structure were fabricated to investigate the variation in the density-of-states with the substrate temperature during deposition of the donor. The maximum open circuit voltage was reached at a substrate temperature of 60 °C. Organic thin-film transistors were also fabricated to study their electrical properties, such as the mobility and the density-of-states. Finally, an organic solar cell with p–i–n structure was fabricated at the optimized substrate temperature, and a power conversion efficiency of almost 4% was obtained.     

A BER-Based Partitioned Model for a 2.4GHz Vehicle-to-Vehicle Expressway Channel

Statistical channel models based on BER performance are presented for a frequency- and time-selective vehicle-to-vehicle wireless communications link in an expressway environment in Atlanta, Georgia, where both vehicles traveled in the same direction. The models are developed from measurements taken using the direct sequence spread spectrum (DSSS) technique at 2.45GHz. A collection of tapped delay line models, referred to as a “partitioned” model in the paper, is developed to attempt to capture the extremes of BER performance of the recorded channel. Overall and partition models are compared to the recorded channel in terms of the BER statistics obtained when the channels are inserted in a dedicated short range radio (DSRC) standard simulation system. The quality of the match between synthesized and recorded channel BER statistics is analyzed with respect to type of modulation (fixed or adaptive), the frame length, and the length of the interval over which the BER was calculated. Guillermo Acosta was born in Mexico City, Mexico, in 1962. He is a Ph.D. Candidate and a graduate research assistant in the School of Electrical and Computer Engineering at the Georgia Institute of Technology, in Atlanta, Georgia. He obtained his Bachelor of Engineering with Honors and Master of Engineering, both in Electrical Engineering, from Stevens Institute of Technology, Hoboken, New Jersey, in 1985 and 1987, respectively. He also obtained a Master of Business Administration with Honors from the Instituto Tecnologico Autonomo de Mexico (ITAM), Mexico City, Mexico, in 1996. Mr. Acosta has held technical and managerial positions in the recording, radio, and TV industries and in the Communications Ministry of Mexico. He has been an adjunct instructor in Electrical Engineering in the Instituto Tecnologico y Estudios Superiores de Monterrey Campus Estado de Mexico (ITESM-CEM) and the Universidad Iberoamericana. He is member of the IEEE, INCE, Tau Beta Pi, and Eta Kappa Nu. Mary Ann Ingram received the B.E.E. and Ph.D. degrees from the Georgia Institute of Technology, in Atlanta, Georgia, in 1983 and 1989, respectively. From 1983 to 1986, she was a Research Engineer with the Georgia Tech Research Institute in Atlanta, performing studies on radar electronic countermeasure (ECM) systems. In 1986, she became a graduate research assistant with the School of Electrical and Computer Engineering at the Georgia Institute of Technology, where in 1989, she became a Faculty Member and is currently Professor. Her early research areas were optical communications and radar systems. In 1997, she established the Smart Antenna Research Laboratory (SARL), which emphasizes the application of multiple antennas to wireless communication systems. The SARL performs system analysis and design, channel measurement, and prototyping, relating to a wide range of wireless applications, including wireless local area network (WLAN) and satellite communications, with focus on the lower layers of communication networks. Dr. Ingram is a Senior Member of the IEEE.