Generalized pairwise z-complementary codes

An approach to generate generalized pairwise Z-complementary (GPZ) codes, which works in pairs in order to offer a zero correlation zone (ZCZ) in the vicinity of zero phase shift and fit extremely well in power efficient quadrature carrier modems, is introduced in this letter. Each GPZ code has MK sequences, each of length 4NK, whereMis the number of Z-complementary mates, K is a factor to perform Walsh–Hadamard expansions, and N is the sequence length of the Z-complementary code. The proposed GPZ codes include the generalized pairwise complementary (GPC)codes as special cases

Mass transfer characteristics in structured packing for CO2 emission reduction processes

Acid gas treating and CO2 capture from flue gas by absorption have gained wide importance over the past few decades. With the implementation of more stringent environmental regulations and the awareness of the greenhouse effect, the need for efficient removal of acid gases such as CO2 (carbon dioxide) has increased significantly. Therefore, additional effort for research in this field is inevitable. For flue gas processes the ratio of absorption solvent to gas throughput is very different compared to acid gas treating processes owing to the atmospheric pressures and the dilution effect of combustion air. Moreover, in flue gas applications pressure drop is a very important process parameter. Packing types are required that allow for low pressure drop in combination with high interfacial areas at low liquid loading per square meter. The determination of interfacial areas in gas-liquid contactors by means of the chemical method (Danckwerts, P. V. Gas-liquid reactions; McGraw-Hill: London, 1970) has been very frequently applied. Unfortunately, many of the model systems proposed in the literature are reversible and therefore this condition possibly is not met. Versteeg et al. (Versteeg, G. F.; Kuipers, J. A. M.; Beckum, F. P. H.; van Swaaij, W. P. M. Chem. Eng. Sci. 1989, 44, 2292) have demonstrated that for reversible reactions the conditions for the determination of the interfacial area by means of the chemical method are much more severe. In a study by Raynal et al. (Raynal, L.; Ballaguet, J. P.; Berrere-Tricca, C. Chem. Eng. Sci. 2004, 59, 5395), it has been shown that there is a dependency of the interfacial area on the packing height. Unfortunately, most model systems used, e.g., CO2-caustic soda (as used by Raynal et al.), are much more complex and consist of (a set of) reversible reaction(s). The natures of these systems make the conditions at which the interfacial area can be determined much more severe and put more limitations on the process conditions and experimental equipment than a priori can be expected. Therefore, an extended absorption model is required to determine the conditions at which the interfacial area can be measured without detailed knowledge of the values of the liquid-side mass transfer coefficient, k1, beforehand.

Global to local genetic diversity indicators of evolutionary potential in tree species within and outside forests

There is a general trend of biodiversity loss at global, regional, national and local levels. To monitor this trend, international policy processes have created a wealth of indicators over the last two decades. However, genetic diversity indicators are regrettably absent from comprehensive bio-monitoring schemes. Here, we provide a review and an assessment of the different attempts made to provide such indicators for tree genetic diversity from the global level down to the level of the management unit. So far, no generally accepted indicators have been provided as international standards, nor tested for their possible use in practice. We suggest that indicators for monitoring genetic diversity and dynamics should be based on ecological and demographic surrogates of adaptive diversity as well as genetic markers capable of identifying genetic erosion and gene flow. A comparison of past and present genecological distributions (patterns of genetic variation of key adaptive traits in the ecological space) of selected species is a realistic way of assessing the trend of intra-specific variation, and thus provides a state indicator of tree genetic diversity also able to reflect possible pressures threatening genetic diversity. Revealing benefits of genetic diversity related to ecosystem services is complex, but current trends in plantation performance offer the possibility of an indicator of benefit. Response indicators are generally much easier to define, because recognition and even quantification of, e.g., research, education, breeding, conservation, and regulation actions and programs are relatively straightforward. Only state indicators can reveal genetic patterns and processes, which are fundamental for maintaining genetic diversity. Indirect indicators of pressure, benefit, or response should therefore not be used independently of state indicators. A coherent set of indicators covering diversity–productivity–knowledge–management based on the genecological approach is proposed for application on appropriate groups of tree species in the wild and in cultivation worldwide. These indicators realistically reflect the state, trends and potentials of the world’s tree genetic resources to support sustainable growth. The state of the genetic diversity will be based on trends in population distributions and diversity patterns for selected species. The productivity of the genetic resource of trees in current use will reflect the possible potential of mobilizing the resource further. Trends in knowledge will underpin the potential capacity for development of the resource and current management of the genetic resource itself will reveal how well we are actually doing and where improvements are required

Probing the mechanism of electron capture and electron transfer dissociation using tags with variable electron affinity

Electron capture dissociation (ECD) and electron transfer dissociation (ETD) of doubly protonated electron affinity (EA)-tuned peptides were studied to further illuminate the mechanism of these processes. The model peptide FQpSEEQQQTEDELQDK, containing a phosphoserine residue, was converted to EA-tuned peptides via β-elimination and Michael addition of various thiol compounds. These include propanyl, benzyl, 4-cyanobenzyl, perfluorobenzyl, 3,5-dicyanobenzyl, 3-nitrobenzyl, and 3,5-dinitrobenzyl structural moieties, having a range of EA from −1.15 to +1.65 eV, excluding the propanyl group. Typical ECD or ETD backbone fragmentations are completely inhibited in peptides with substituent tags having EA over 1.00 eV, which are referred to as electron predators in this work. Nearly identical rates of electron capture by the dications substituted by the benzyl (EA = −1.15 eV) and 3-nitrobenzyl (EA = 1.00 eV) moieties are observed, which indicates the similarity of electron capture cross sections for the two derivatized peptides. This observation leads to the inference that electron capture kinetics are governed by the long-range electron−dication interaction and are not affected by side chain derivatives with positive EA. Once an electron is captured to high-n Rydberg states, however, through-space or through-bond electron transfer to the EA-tuning tags or low-n Rydberg states via potential curve crossing occurs in competition with transfer to the amide π* orbital. The energetics of these processes are evaluated using time-dependent density functional theory with a series of reduced model systems. The intramolecular electron transfer process is modulated by structure-dependent hydrogen bonds and is heavily affected by the presence and type of electron-withdrawing groups in the EA-tuning tag. The anion radicals formed by electron predators have high proton affinities (approximately 1400 kJ/mol for the 3-nitrobenzyl anion radical) in comparison to other basic sites in the model peptide dication, facilitating exothermic proton transfer from one of the two sites of protonation. This interrupts the normal sequence of events in ECD or ETD, leading to backbone fragmentation by forming a stable radical intermediate. The implications which these results have for previously proposed ECD and ETD mechanisms are discussed

A Small Acoustic Goniometer for General Purpose Research

Understanding acoustic events and monitoring their occurrence is a useful aspect of many research projects. In particular, acoustic goniometry allows researchers to determine the source of an event based solely on the sound it produces. The vast majority of acoustic goniometry research projects used custom hardware targeted to the specific application under test. Unfortunately, due to the wide range of sensing applications, a flexible general purpose hardware/firmware system does not exist for this purpose. This article focuses on the development of such a system which encourages the continued exploration of general purpose hardware/firmware and lowers barriers to research in projects requiring the use of acoustic goniometry. Simulations have been employed to verify system feasibility, and a complete hardware implementation of the acoustic goniometer has been designed and field tested. The results are reported, and suggested areas for improvement and further exploration are discussed

A QoS-based flow assignment for traffic engineering in software-defined networks

In order to meet a tremendous amount of data storage requirement in next-generation wireless networks, an increasing number of cloud data centers has been deployed around the world. The underlying core networks are expected to provide the ability to store data in a dynamic and scalable computing environment. The traditional Internet Protocol (IP) has shown to be restricted due to its static architecture, which accordingly motivates the development of Software-Defined Networks (SDNs). In the SDNs, Traffic Engineering (TE) is simpler and programmable with a controller without the requirement of reconfiguration for all network devices. However, the existing TE algorithm of the SDNs rejects a number of requested flows caused by their undetermined routing paths where only flow bandwidth is considered in path determination. This paper proposes a Quality-of-Service (QoS) based Flow Assignment algorithm which enables the computation of end-to-end path for traffic flows guaranteeing the QoS requirements including bandwidth, end-to-end delay and packet loss probability. Through the Open Source Hybrid IP/SDNs platform, the proposed algorithm is validated and shown to significantly reduce flow rejection rate of up to 50% compared to the conventional approach, and therefore can be used to implement an effective DiffServ mechanism for flow allocation in the SDNs

Preparation of Subradiant States using Local Qubit Control in Circuit QED

Transitions between quantum states by photon absorption or emission are intimately related to symmetries of the system which lead to selection rules and the formation of dark states. In a circuit quantum electrodynamics setup, in which two resonant superconducting qubits are coupled through an on-chip cavity and driven via the common cavity field, one single-excitation state remains dark. Here, we demonstrate that this dark state can be excited using local phase control of individual qubit drives to change the symmetry of the driving field. We observe that the dark state decay via spontaneous emission into the cavity is suppressed, a characteristic signature of subradiance. This local control technique could be used to prepare and study highly correlated quantum states of cavity-coupled qubits.Comment: 5 pages, 4 figure

Step-free railway station access in the UK: The value of inclusive design

Background: Despite substantial investment in step-free access at UK railway stations, persons with reduced mobility (PRMs) continue to travel less than their able-bodied counterparts and little is known about the value of step-free access. This research examines the benefits of step-free access and its relationship with rail usage among PRMs, and the wider benefits of railway station accessibility. Methods: These issues are explored through a mixed methods approach. Semi-structured interviews with ten key organisations were undertaken, as was an analysis of Senior/Disabled Persons Railcard data from 17 railway stations in Buckinghamshire, each with varying levels of step-free accessibility. Results: The results show that the benefits of step-free access extend beyond benefits at the individual level typically associated with those limited to PRMs, and demonstrate the potential to positively affect the society at large economically, environmentally, and socially. The findings also show a positive correlation between the level of step-free accessibility at a railway station and the percentage of PRMs using it. Conclusions: This research argues that government and interested stakeholders should commit to expanding the number and coverage of step-free stations throughout the UK. They should ensure that the appraisal process for investment in step-free accessibility appropriately captures both user and non-user benefits

Taxometrics Classification (Hierarchical and Ordination) of Aquatic and Semi-aquatic Mosses: a Preliminary Model to Bryodiversity Management

Bryodiversity is naturally serving the ecosystems sustainably. It serves the environments by preventing natural disaster (flooding), maintaining the quality of the water body and filter or treats the pollutants naturally. Efficient bryodiversity management is needed for environmental cost cutting and have a cost-effective management strategy. To achieve this, cluster and principal component analyses (PCA) were manipulated to produce the linkage distance between the OTUs and identify the important groups of characters, respectively. In return, it becomes a guideline for bryoflora and environmental managements. In this study, 23 OTUs and 156 characters were analyzed. The output from the reliability and item analysis showed that the data set is highly reliable (Cronbach's alpha = 0.9627). From the cluster analysis, it showed that 5 clustered groups (manageable units) could be derived from the produced phenogram. This is based on the nearest neighbour amalgation rule and Euclidean distances. As for the principal component analysis, three factors were derived and explained 75.1064% of the variation with 56.0485%(PC1), 11.7346%(PC2) and 7.3233%(PC3), respectively. The ordination showed that 5 manageable units were derived from PC1 and 3 manageable units for PC2 and PC3, respectively. In conclusion, conservation should precede any biodiversity management plans