Analysis of coffee cut-stems (CCS) as raw material for fuel ethanol production

Coffee cut-stems (CCS) represent a promising candidate for fuel ethanol production in tropical countries because of their high availability and high biomass yield per hectare. In this work, pretreatment of this agricultural residue with dilute sulfuric acid and liquid hot water (LHW) was integrated in the simulation and economic assessment of the process for fuel ethanol production. High reducing sugars concentration and ethanol yields were obtained with the LHW pretreatment at a high energy cost. Acid pretreatment is still one of the most applied technologies for lignocellulosic materials due to its efficiency and lower energy consumption. For the determination of the pollution environmental impact index of the process with and without cogeneration system, the Waste Reduction Algorithm (WAR) was used. Thus, the high lignin and low water contents of the coffee cut-stems signified a high potential for energy cogeneration.     

Polymerase chain reaction products (PCR) on “DNA barcode zone” resolved by temporal temperature gradient electophoresis: A tool for species identification of mixed meat specimens – A technical note on preliminary results

The capability of PCR-TTGE to detect meat species in mixed animal samples was investigated as a necessary step in developing a method where the identification will be performed matching on the “DNA barcode” zone the sequences of resolved PCR products obtained from a limited set of “universal” primers. Exemplary mixtures from five important meat species were analyzed. At this stage more PCR reactions have to be applied on a sample but this should be easily improved using primers simultaneously (as a “cocktail”) in a single reaction.     

An FPGA implementation of the AES-Rijndael in OCB/ECB modes of operation

Implementation in one FPGA of the AES-Rijndael in Offset Codebook (OCB) and Electronic Codebook (ECB) modes of operation was developed and experimentally tested using the Insight Development Kit board, based on Xilinx Virtex II XC2V1000-4 device. The circuit was designed to provide simultaneous data privacy and authenticity in applications which require small area such as wireless LANs, cellular phones, and smart cards. The experimental clock frequency was equal to 50 MHz and translates to the throughputs of 493 Mbit/s for block size and key size of 128 bits, respectively. The circuit combines the efficiency of OCB authentication with the high security of Rijndael encryption/decryption algorithms, offering an authenticated encryption/decryption scheme.     

Sequence–Structure–Property Relationships of Recombinant Spider Silk Proteins: Integration of Biopolymer Design,Processing, and Modeling

The mechanical properties of spider silks drive interest as sources of new materials. However, there remains a lot to learn regarding the relationships between sequence, structure, and mechanical properties. In order to predict the types of sequence–functional relationships, synthesis–characterization–computation are integrated using recombinant spider silk‐like block copolymers. Two designs are studied, both with origins from the spider Nephila clavipes. These proteins are studied both experimentally and in silico to understand the relationships between sequence chemistry, processing, structure, and materials function. Films formed from the two proteins are thoroughly characterized. In parallel, molecular modeling is used to assess the propensity of the two sequences to form β‐sheets or crystalline structures. The results demonstrate that the modeling predicts the structural differences between the two silk‐like polymers and these features can also be related to differences in functional outcomes. With this example of relating sequence design (hydrophobic–hydrophilic domains), experiment (genetic design and synthesis), processing (film and fiber formation) and modeling (predictions of crystallinity), synergy among these methods is demonstrated for predictable material outcomes. This approach offers a robust discovery path when looking towards next generation approaches to targeted materials outcomes.     

Dependability modeling of real-time systems using stochastic reward nets

Dependability modeling plays a major role in the design, validation and maintenance of real-time computing systems. Typical models provide measures such as mean time to failure, reliability and safety as functions of the component failure rates and fault/error coverage probabilities. In this paper we propose a modeling technique that allows the coverage to be dependent upon the local (i.e. embedded at task level) and global (i.e. available at system level) fault/error detection and recovery mechanisms. This approach also ensures important savings in terms of the simulation time required for deriving the coverage probabilities. Stochastic. reward nets are employed as a unique dependability modeling framework. For illustrating the usefulness of this technique we analyze dependability of a railroad control computer.     

Measuring the uniqueness and variety of analog circuit design features

Analog circuit design activity is currently a less formalized process, in which the main source for innovation is the designer's ability to produce new designs by combining basic devices, sub-circuits, and ideas from similar solutions. There are few systematic methods that can fuse and transform the useful features of the existing designs into new solutions. Moreover, most automated circuit synthesis tools are still limited to routine tasks, like transistor sizing and layout design. Developing new design techniques that can combine the existing design features requires metrics that describe the uniqueness and variety of the features. This paper evaluates for analog circuits two such general-purpose metrics proposed in [1] and [2]. Three case studies are discussed on using the metrics to characterize the design features of current mirrors, transconductors, and operational amplifiers. The two metrics and the presented study is useful in producing an overall characterization of analog circuit features. This can help in enhancing the circuit design process, training of young designers, and developing new automated synthesis tools that can explore more solution space regions that are likely to include novel design features.     

MobiSoC: a middleware for mobile social computing applications

Recently, we started to experience a shift from physical communities to virtual communities, which leads to missed social opportunities in our daily routine. For instance, we are not aware of neighbors with common interests or nearby events. Mobile social computing applications (MSCAs) promise to improve social connectivity in physical communities by leveraging information about people, social relationships, and places. This article presents MobiSoC, a middleware that enables MSCA development and provides a common platform for capturing, managing, and sharing the social state of physical communities. Additionally, it incorporates algorithms that discover previously unknown emergent geo-social patterns to augment this state. To demonstrate MobiSoC's feasibility, we implemented and tested on smart phones two MSCAs for location-based mobile social matching and place-based ad hoc social collaboration. Experimental results showed that MobiSoC can provide good response time for 1,000 users. We also demonstrated that an adaptive localization scheme and carefully chosen cryptographic methods can significantly reduce the resource consumption associated with the location engine and security on smart phones. A user study of the mobile social matching application proved that geo-social patterns can double the quality of social matches and that people are willing to share their location with MobiSoC in order to benefit from MSCAs.

A new family of optimized orthogonal Space-Times codes for PPM-based MIMO systems with imperfect channel estimates

In this contribution, we develop a single Multiple-Input Multiple Output (MIMO) transceiver for Orthogonal PPM (OPPM) data transmitted over (baseband) faded MIMO channels with a priori unknown path-gains. The signaling-scheme we adopt allows to equip the Maximum-Likelihood receiver with reliable estimates of the (possibly time-varying) MIMO channel, without reducing the conveyed information throughput. Hence, after evaluating the performance of the proposed transceiver via a suitable version of the Union-Chernoff Bound, we introduce a novel family of unitary orthogonal Space-Times Block Codes (e.g., the Space-Time OPPM codes), that are able to attain both maximum diversity and coding gains. Afterwards, we present closed-form formulas for evaluating the SNR loss induced by mistiming effects possibly impairing the received signals. Lastly, we report several numerical results supporting both the medium/long coverage ranges attained by the proposed transceiver in outdoor applications and its performance robustness against correlated channel fading, mistiming effects and degradation induced by dense-multipath fading. This work is partially supported by Italian National Project Women 2005093248     

Multiresolution Abnormal Trace Detection Using Varied-Length n-Grams and Automata

Detection and diagnosis of faults in a large-scale distributed system is a formidable task. Interest in monitoring and using traces of user requests for fault detection has been on the rise recently. In this paper we propose novel fault detection methods based on abnormal trace detection. One essential problem is how to represent the large amount of training trace data compactly as an oracle. Our key contribution is the novel use of varied-length n-grams and automata to characterize normal traces. A new trace is compared against the learned automata to determine whether it is abnormal. We develop algorithms to automatically extract n-grams and construct multiresolution automata from training data. Further, both deterministic and multihypothesis algorithms are proposed for detection. We inspect the trace constraints of real application software and verify the existence of long n-grams. Our approach is tested in a real system with injected faults and achieves good results in experiments     

CNTs in Optoelectronic Devices: New Structural and Photophysical Insights on Porphyrin‐DWCNTs Hybrid Materials

The preparation and physical characterization of diverse porphyrin‐derived double‐walled carbon nanotubes (DWCNTs) conjugates are described. A porphyrin molecule is covalently linked and physically adsorbed to COOH‐derived DWCNTs. The photophysical properties of all porphyrin‐CNTs derivatives are studied in solution and in polymeric matrices. Definitive experimental evidence for photoinduced electron and/or energy transfer processes involving the porphyrin chromophores and the CNT wall is not obtained, but solid‐state UV‐vis absorption profiles display electronic transitions fingerprinting J‐ and H‐ type aggregates, where porphyrin molecules intermolecularly interact “head‐to‐tail” and “face‐to‐face”, respectively. In parallel, molecular modeling based on force‐field simulations is performed to understand the structure of the porphyrin‐CNTs interface and the nature of the interactions between the porphyrins and the DWCNTs. Finally, multilayered ‐ type devices are fabricated with the aim of investigating the interaction of the porphyrin‐derived DWCNTs with poly(3‐hexylthiophene)‐pyrene matrices containing small amounts of 1‐[3‐(methoxycarbonyl)propyl]‐1‐phenyl‐[6.6]C₆₁.