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Challenges, Volume 7, Issue 2 (December 2016)

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Editorial

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Open AccessEditorial Innovations in Detection of Deliberate or Accidental Contamination with Biological Agents in Environment and Foods
Challenges 2016, 7(2), 22; doi:10.3390/challe7020022
Received: 29 November 2016 / Revised: 30 November 2016 / Accepted: 30 November 2016 / Published: 7 December 2016
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Research

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Open AccessArticle A Linear Bayesian Updating Model for Probabilistic Spatial Classification
Challenges 2016, 7(2), 21; doi:10.3390/challe7020021
Received: 8 September 2016 / Revised: 28 October 2016 / Accepted: 21 November 2016 / Published: 29 November 2016
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Abstract
Categorical variables are common in spatial data analysis. Traditional analytical methods for deriving probabilities of class occurrence, such as kriging-family algorithms, have been hindered by the discrete characteristics of categorical fields. To solve the challenge, this study introduces the theoretical backgrounds of the
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Categorical variables are common in spatial data analysis. Traditional analytical methods for deriving probabilities of class occurrence, such as kriging-family algorithms, have been hindered by the discrete characteristics of categorical fields. To solve the challenge, this study introduces the theoretical backgrounds of the linear Bayesian updating (LBU) model for spatial classification through an expert system. The main purpose of this paper is to present the solid theoretical foundations of the LBU approach. Since the LBU idea is originated from aggregating expert opinions and is not restricted to conditional independent assumption (CIA), it may prove to be reasonably adequate for analyzing complex geospatial data sets, such as remote sensing images or area-class maps. Full article
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Open AccessArticle Stand-Off Device for Plastic Debris Recognition in Post-Blast Scenarios
Challenges 2016, 7(2), 23; doi:10.3390/challe7020023
Received: 28 October 2016 / Revised: 2 December 2016 / Accepted: 12 December 2016 / Published: 15 December 2016
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Abstract
The fast analysis of crime scenes is a very critical issue for investigators that should collect, as much as possible, all and only meaningful evidence, and rapidly bring back to normality the involved area. With the scope to respond to the end user’s
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The fast analysis of crime scenes is a very critical issue for investigators that should collect, as much as possible, all and only meaningful evidence, and rapidly bring back to normality the involved area. With the scope to respond to the end user’s requirements, the project FORLAB (Forensic Laboratory for in-situ evidence analysis in a post blast scenario) has set, as its main goal, to develop a system of sensors for fast screening of post-blast scenes. In this frame, a new sensor based on laser induced fluorescence has been developed for standoff individuation and localization of plastic debris in post-blast scenarios. The system can scan large areas in short times (in some cases, minutes) providing real-time images of the scene where material discrimination is highlighted. In fact, the combined use of a laser source with a high repetition rate and of a signal collection setup based on a fixed intensified charged coupled device (ICCD) with a large field of view has allowed for the brief duration of the scanning process. In addition, dedicated software elaborates the fluorescence data obtained from the targets and retrieves a chemical characterization useful for material recognition. Full article
(This article belongs to the Special Issue Challenges in New Technologies for Security)
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Open AccessArticle Validation of a Miniaturized Spectrometer for Trace Detection of Explosives by Surface-Enhanced Raman Spectroscopy
Challenges 2016, 7(2), 14; doi:10.3390/challe7020014
Received: 7 June 2016 / Revised: 8 August 2016 / Accepted: 10 August 2016 / Published: 19 August 2016
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Abstract
Surface-enhanced Raman spectroscopy (SERS) measurements of some common military explosives were performed with a table-top micro-Raman system integrated with a Serstech R785 miniaturized device, comprising a spectrometer and detector for near-infrared (NIR) laser excitation (785 nm). R785 was tested as the main component
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Surface-enhanced Raman spectroscopy (SERS) measurements of some common military explosives were performed with a table-top micro-Raman system integrated with a Serstech R785 miniaturized device, comprising a spectrometer and detector for near-infrared (NIR) laser excitation (785 nm). R785 was tested as the main component of a miniaturized SERS detector, designed for in situ and stand-alone sensing of molecules released at low concentrations, as could happen in the case of traces of explosives found in an illegal bomb factory, where solid microparticles of explosives could be released in the air and then collected on the sensor’s surface, if placed near the factory, as a consequence of bomb preparation. SERS spectra were obtained, exciting samples in picogram quantities on specific substrates, starting from standard commercial solutions. The main vibrational features of each substance were clearly identified also in low quantities. The amount of the sampled substance was determined through the analysis of scanning electron microscope images, while the spectral resolution and the detector sensitivity were sufficiently high to clearly distinguish spectra belonging to different samples with an exposure time of 10 s. A principal component analysis procedure was applied to the experimental data to understand which are the main factors affecting spectra variation across different samples. The score plots for the first three principal components show that the examined explosive materials can be clearly classified on the basis of their SERS spectra. Full article
(This article belongs to the Special Issue Challenges in New Technologies for Security)
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Open AccessArticle Early Warning of Biological Threats via Surface-Enhanced Raman Spectroscopy: A Case Study of Bacillus Spores
Challenges 2016, 7(2), 24; doi:10.3390/challe7020024
Received: 31 October 2016 / Revised: 15 December 2016 / Accepted: 16 December 2016 / Published: 20 December 2016
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Abstract
A study on the application of surface-enhanced Raman spectroscopy (SERS) in detecting biological threats is here reported. Simulants of deadly Bacillus anthracis endospores were used. This study proposes an automated device where SERS is used as a fast, pre-alarm technique of a two-stage
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A study on the application of surface-enhanced Raman spectroscopy (SERS) in detecting biological threats is here reported. Simulants of deadly Bacillus anthracis endospores were used. This study proposes an automated device where SERS is used as a fast, pre-alarm technique of a two-stage sensor equipped with a real-time polymerase chain reaction (PCR). In order to check the potentialities of SERS in terms of sensitivity and specificity for on-site, real-time, automatic detection and identification of biological agents, two strains of genetically and harmless closely B. anthracis-related spores, Bacillus thuringiensis and Bacillus atrophaeus, were used as simulants. In order to assure the selectivity of the SERS substrate against B. thuringiensis spores, the substrate was functionalized by specific peptides. The obtained SERS measurements are classified as positive or negative hits by applying a special data evaluation based on the Euclidian distance between each spectrum and a reference spectrum of blank measurement. Principal component analysis (PCA) was applied for discriminating between different strains representing dangerous and harmless spores. The results show that the SERS sensor is capable of detecting a few tenths of spores in a few minutes, and is particularly sensitive and fast for this purpose. Post-process analysis of the spectra allowed for discrimination between the contaminated and uncontaminated SERS sensors and even between different strains of spores, although not as clearly. For this purpose, the use of a non-functionalized SERS substrate is suggested. Full article
(This article belongs to the Special Issue Challenges in New Technologies for Security)
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Open AccessFeature PaperArticle Field Prototype of the ENEA Neutron Active Interrogation Device for the Detection of Dirty Bombs
Challenges 2016, 7(2), 17; doi:10.3390/challe7020017
Received: 14 June 2016 / Revised: 13 October 2016 / Accepted: 14 October 2016 / Published: 19 October 2016
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Abstract
The Italian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA) Neutron Active Interrogation (NAI) device is a tool designed to improve CBRNE defense. It is designed to uncover radioactive and nuclear threats including those in the form of Improvised Explosive
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The Italian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA) Neutron Active Interrogation (NAI) device is a tool designed to improve CBRNE defense. It is designed to uncover radioactive and nuclear threats including those in the form of Improvised Explosive Devices (IEDs), the so-called “dirty bombs”. The NAI device, at its current development stage, allows to detect 6 g of 235U hidden in a package. It is easily transportable, light in weight, and with a real-time response. Its working principle is based on two stages: (1) an “active” stage in which neutrons are emitted by a neutron generator to interact with the item under inspection, and (2) a “passive” stage in which secondary neutrons are detected originating a signal that, once processed, allows recognition of the offence. In particular, a clear indication of the potential threat is obtained by a dedicated software based on the Differential Die-Away Time Analysis method. Full article
(This article belongs to the Special Issue Challenges in New Technologies for Security)
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Open AccessArticle Optimization of Plating Conditions for the Determination of Polonium Using Copper Foils
Challenges 2016, 7(2), 18; doi:10.3390/challe7020018
Received: 28 June 2016 / Revised: 12 October 2016 / Accepted: 13 October 2016 / Published: 21 October 2016
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Abstract
The technique of adsorption of polonium onto metal surfaces by spontaneous deposition has found applications in the analysis of environmental samples such as marine sediments, foodstuff, water, and tobacco since the 1960s. Silver foil has been preferred by many scientists but can become
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The technique of adsorption of polonium onto metal surfaces by spontaneous deposition has found applications in the analysis of environmental samples such as marine sediments, foodstuff, water, and tobacco since the 1960s. Silver foil has been preferred by many scientists but can become quite expensive for routine analysis. Deposition onto copper was first proposed in the 1970s, but has remained poorly studied. In the present study, the cost-effective and rapid optimum conditions necessary for the optimal recovery of Po from aqueous solutions during spontaneous deposition onto copper foils was evaluated while minimizing the deposition of Bi and Pb, which may interfere with subsequent analyses. A series of experiments was performed to determine adsorption yields for Po, Bi, and Pb to copper foils for a range of pH values from 1.0 to 5.5, with and without stable Bi and Pb carriers. Different methods for cleaning the copper foils were also compared. After initial measurements, Po, Bi, and Pb were desorbed from the disc in plating solutions without added activity. At higher pH values (3.0 and 5.5), less Bi was adsorbed to the copper foils, and subsequent desorption removed up to 99.1% of the plated Bi. The polonium yield remained fairly constant at all pH values and was unaffected by the desorption process. There was also no measureable increase in the polonium activity after 33 days, suggesting that Bi and Pb were not significantly co-deposited. All three cleaning methods performed well, whereas uncleaned foils in the same solution showed limited uptake. The use of copper foil under the optimum conditions described here could provide a valuable alternative to the use of silver in 210Po analyses. Full article
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Review

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Open AccessReview Challenges in Specialty Coffee Processing and Quality Assurance
Challenges 2016, 7(2), 19; doi:10.3390/challe7020019
Received: 24 June 2016 / Revised: 26 August 2016 / Accepted: 17 October 2016 / Published: 24 October 2016
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Abstract
Coffee is an important crop that assures a sustainable economy to farmers in tropical regions. A dramatic concern for coffee production is currently represented by climate change, which threatens the survival of Coffea arabica cultivation worldwide and imposes modifications of the agronomic practices
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Coffee is an important crop that assures a sustainable economy to farmers in tropical regions. A dramatic concern for coffee production is currently represented by climate change, which threatens the survival of Coffea arabica cultivation worldwide and imposes modifications of the agronomic practices to prevent this risk. The quality of coffee beans depends on optimized protocols of cultivation, ripe berries collection, and removal of the outer fruit layers by dry or wet processes and moisture reduction. Storage and shipment represent two steps where bean quality needs to be preserved by preventing fungal contamination that may impact the final product and form mycotoxins, mainly ochratoxin A. In this review, we describe the challenges faced by the coffee industry to guarantee quality from production to roasting and brewing. An overview of novel technologies, such as the application of starter cultures in fermentation and the exploitation of industrial enzymes in accelerating the process of flavour development in coffee beans, is given. Moreover, the results of studies on microbial populations on coffee and the differences found in fungi, yeasts and bacteria composition among the investigations, are summarized. In particular, this review describes new attempts to contain the development of mycotoxigenic fungi, through the application of antagonistic microorganisms such as S. cerevisiae. The new wave of specialty coffees, i.e., those with a cupping score higher than 85/100, is also presented. It is shown how, through careful coffee production methods and controlled fermentation processes, coffee producers may increase their income by assuring high standards of quality and high added value for the coffee experience sector. Full article
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Other

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Open AccessOpinion Technical Problem Identification for the Failures of the Liberty Ships
Challenges 2016, 7(2), 20; doi:10.3390/challe7020020
Received: 25 August 2016 / Revised: 31 October 2016 / Accepted: 1 November 2016 / Published: 8 November 2016
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Abstract
The U.S. Liberty Ship Building Program in World War II set a record—a total of 2700 Liberty Ships were built in 6 years, in order to support the battle against Nazi-Germany. However, numerous vessels suffered sudden fracture, some of them being split in
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The U.S. Liberty Ship Building Program in World War II set a record—a total of 2700 Liberty Ships were built in 6 years, in order to support the battle against Nazi-Germany. However, numerous vessels suffered sudden fracture, some of them being split in half. This paper demonstrates and investigation of the Liberty Ships failure and problems, which reveals that the failures are caused by a combination of three factors. The welds produced by largely unskilled work force contain crack type flaws. Beyond these cracks, another important reason for failure associated with welding is the hydrogen embitterment; most of the fractures initiate at deck square hatch corners where there is a stress concentration; and the ship steel has fairly poor Charpy-Impact tested fracture toughness. It has been admitted that, although the numerous catastrophic failures were a painful experience, the failures of the Liberty Ships caused significant progress in the study of fracture mechanics. Considering their effect, the Liberty Ships are still a success. Full article
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Open AccessConcept Paper Putting Soil Security on the Policy Agenda: Need for a Familiar Framework
Challenges 2016, 7(2), 15; doi:10.3390/challe7020015
Received: 4 July 2016 / Revised: 16 August 2016 / Accepted: 23 September 2016 / Published: 29 September 2016
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Abstract
Soils generate agricultural, environmental, and socio-economic benefits that are vital to human life. The enormity of threats to global soil stocks raises the imperative for securing this vital resource. To contribute to the security framing and advancement of the soil security concept and
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Soils generate agricultural, environmental, and socio-economic benefits that are vital to human life. The enormity of threats to global soil stocks raises the imperative for securing this vital resource. To contribute to the security framing and advancement of the soil security concept and discourse, this paper provides a working definition and proposes dimensions that can underpin the conceptualization of soil security. In this paper, soil security refers to safeguarding and improving the quality, quantity and functionality of soil stocks from critical and pervasive threats in order to guarantee the availability, access, and utilization of soils to sustainably generate productive goods and ecosystem services. The dimensions proposed are availability, accessibility, utilization, and stability, which are obviously similar to the dimensions of food security. Availability refers to the quality and spatial distribution of soils of a given category. Accessibility relates to the conditions or mechanisms by which actors negotiate and gain entitlements to occupy and use a given soil. Utilization deals with the use or purpose to which a given soil is put and the capacity to manage and generate optimal private and public benefits from the soil. Finally, stability refers to the governance mechanisms that safeguard and improve the first three dimensions. These dimensions, their interactions, and how they can be operationalized in a strategy to secure soils are presented and discussed. Full article
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Open AccessConcept Paper Soft Energy Paths Revisited: Politics and Practice in Energy Technology Transitions
Challenges 2016, 7(2), 16; doi:10.3390/challe7020016
Received: 22 August 2016 / Revised: 10 October 2016 / Accepted: 12 October 2016 / Published: 14 October 2016
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Abstract
This paper argues that current efforts to study and advocate for a change in energy technologies to reduce their climate and other environmental impacts often ignore the political, social, and bodily implications of energy technology choices. Framing renewable energy technologies exclusively in terms
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This paper argues that current efforts to study and advocate for a change in energy technologies to reduce their climate and other environmental impacts often ignore the political, social, and bodily implications of energy technology choices. Framing renewable energy technologies exclusively in terms of their environmental benefits dismisses important questions about how energy infrastructures can be designed to correspond to democratic forms of socio-politics, forms of social organization that involve independence in terms of meeting energy needs, resilience in terms of adapting to change, participatory decision making and control, equitable distribution of knowledge and efficacy, and just distribution of ownership. Recognizing technological choices as political choices brings explicit attention to the kinds of socio-political restructuring that could be precipitated through a renewable energy technology transition. This paper argues that research on energy transitions should consider the political implications of technological choices, not just the environmental consequences. Further, emerging scholarship on energy practices suggests that social habits of energy usage are themselves political, in that they correspond to and reinforce particular arrangements of power. Acknowledging the embedded politics of technology, as the decades’ old concept of soft path technologies encourages, and integrating insights on the politics of technology with insights on technological practices, can improve future research on energy policy and public perceptions of energy systems. This paper extends insights regarding the socio-political implications of energy paths to consider how understandings of energy technologies as constellations of embedded bodily practices can help further develop our understanding of the consequences of energy technologies, consequences that move beyond environmental implications to the very habits and behaviors of patterned energy usage, which are themselves arguably political. This paper calls for future research that involves explicit examination of the relationship between technologies, socio-political distributions of power and access to energy resources, the social organization of energy practices, and options for energy transitions not just in terms of energy source, but also in terms of scale, design, and modes of ownership and control. Full article

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