ALBERT

Beschreibung: This final reply responds to Honohan’s invitation to articulate the Arendtian tone of the key-note paper. It spells out the philosophical intuition that the political life of citizens, at least potentially, is capable of making visible what makes human life worthwhile and fully meaningful, and the philosophical curiosity to see whether traces of this deep political awareness can be retrieved in dialogues with volunteers. In response to Dekker’s critical doubts, this final reply clarifies the central stakes of Claes’s paper. The core argument was not to show that the biographical model of meaningfulness is the prevailing approach of meaning in/of volunteering, but to assess the potentials and limits of the model’s interpretive power. Moreover, the paper argues for an alternative, existential model of meaningfulness. This approach refers to deep experiences of meaning that emerge from the practice of volunteering and that shift into powerful political experiences of hope, and a lived sense of equality.

Beschreibung: In this comment-response Mikael Lindfelt makes some suggestions to how one could develop the argument for wit(h)nessing as experiencing meaningfulness in life as put forward by Nicole Note and Emilie Van Deale. While being positive to the main phenomenological approach, and especially the dialectical relational aspect of the phenomenological argument, Lindfelt uses Alain Badiou’s talk of Event in trying both to develop the phenomenological argument and to point out some idealistic tendencies in the line of the argument. Lindfelt suggests that the aspect of uniqueness in the relational experience of the other should be taken to more radically than suggested by Note and Van Deale. By pointing out the dialectical fragility of the Event of wit(h)nessing Lindfelt is arguing for that the concept of respect could be more utilized in arguing for the experience of meaning seen as a gift.

Beschreibung: Motion control of a single molecule through a solid-state nanopore offers a new perspective on detecting and analyzing single biomolecules. Repeat recapture of a single DNA molecule reveals the dynamics in DNA translocation through a nanopore and may significantly increase the signal-to-noise ratio for DNA base distinguishing. However, the transient current at the moment of voltage reversal prevents the observation of instantly recaptured molecules and invalidates the continuous DNA ping-pong control. We performed and analyzed the DNA translocation and recapture experiment in a silicon nitride solid-state nanopore. Numerical calculation of molecular motion clearly shows the recapture dynamics with different delay times. The prohibited time when the data acquisition system is saturated by the transient current is derived by equivalent circuit analysis and finite element simulation. The COMSOL simulation reveals that the membrane capacitance plays an important role in determining the electric field distribution during the charging process. As a result of the transient charging process, a non-constant driving force pulls the DNA back to nanopores faster than theoretically predicted. The observed long time constant in the transient current trace is explained by the dielectric absorption of the membrane capacitor.

Beschreibung: Plants have considerable hydrological and mechanical impacts on soil. However, there are lack of documentation and limited understanding on the hydrological and mechanical impacts of tropical legume trees. Therefore, this study was aimed to investigate the hydrological and mechanical properties of three selected legume plants, Leucaena leucocephala , Adenanthera pavonina and Peltophorum pterocarpum . Regarding hydrological aspect, the study results indicated that soil on which the L. leucocephala was grown had the highest transpiration rate, water absorption rate (WAR) and soil matric suction (SMS). In terms of mechanical characteristics, L. leucocephala exhibited the highest root tensile strength and cellulosic components in the root. Interestingly, L. leucocephala also showed a higher root biomass, root length and fine roots than A . pavonina and P. pterocarpum. The leaf area index (LAI) strongly correlated with SMS ( R 2  = 0.74), indicating that high LAI improved SMS. The high root tensile strength and fine roots of L. leucocephala make this species special for growing as a soil reinforcing plant. Overall results suggested that L. leucocephala exhibited outstanding hydrological and mechanical properties and can be a potential plant for the soil reinforcement program.

Beschreibung: We presented an integrated software system for analyzing nanopore data. This self-developed software provided rapid processes for accurate location, classification, and evaluation of every individual blockade. Using the proposed software, statistical analysis could be achieved easily and conveniently. The results of β -Amyloid 42 demonstrated that our data process could rapidly extract duration time and current amplitudes. In addition, our data process could accurately carry out statistical fittings.

Beschreibung: A novel phenol-linked bis(imidazolium) salt, H 3 LCl 2 (L =  O -4-C(CH 3 ) 3 -C 6 H 2 -2,6-di[CH 2 {C(NCHCHNAr)}] 2 , Ar = 2,6-diisopropylphenyl, 1 ), was designed and used to prepare an ionic iron(III) complex [H 2 L][FeCl 4 ] ( 2 ). Complex 2 was a highly efficient catalyst for aryl Grignard cross-coupling of alkyl chlorides bearing β-hydrogens. Furthermore, complex 2 was reusable and could be reused in at least eight times without significant loss in catalytic activity.

Beschreibung: Vertically aligned TiO 2 nanotube arrays (~8 μm long, ~110 nm wide) have been fabricated through anodic oxidation of Ti-metal sheet in fluoride-containing electrolyte. By changing the volume ratio of ethylene glycol and diethylene glycol in the electrolyte, TiO 2 nanotube arrays with different tube-to-tube lateral spacing, i.e., closely packed, just separated, and fully separated, have been synthesized and applied as photoanodes for dye-sensitized solar cells (DSSCs). Photovoltaic efficiency of 2.99 %, 3.34 %, and 3.44 % has been obtained for DSSCs based on the closely packed, just separated, and fully separated TiO 2 nanotube arrays, respectively, illustrating the effect of tube-to-tube lateral spacing of TiO 2 nanotube arrays on the performances of DSSCs. It is suggested that fully separated TiO 2 nanotube arrays are beneficial to the conversion efficiency of DSSCs due to higher dye loading and faster electron transfer.

Beschreibung: Vegetation phenology is an important indicator of climate change impacts on the seasonal dynamics of the biosphere. However, little is known about the influence of elevation on spring phenological sensitivity to temperature in an alpine ecosystem. Based on remotely sensed land surface phenology and temperature data from 2001 to 2010, this study investigated the rate of spring phenological change of the Tibetan Plateau (TP) grasslands in response to interannual temperature variations at different elevations. Results suggest that spring phenology in the TP grasslands exhibits a stronger response to changes in temperature at higher elevations than at lower ones. In particular, spring phenology advanced by 1–2 days in response to a 1 °C increase in May average temperature at elevations from 3,000 to 3,500 m, while the rate was up to 8–9 days/°C at 5,000–5,500 m. Analysis using accumulated growing degree days (AGDD) from January 1 through May 31 showed the same general trend with increased elevation associated with increased sensitivity (as measured by phenological change per unit of AGDD change). Such temperature sensitivity gradients in the TP grasslands could be partly explained by the growth efficiency hypothesis which suggests that vegetation adapted to colder climates likely requires less heat energy for the onset of growing season and vice versa in warmer climates. Furthermore, accumulated growing degree days from January 1 to the greenup date were found to decrease with increasing elevations, which provided evidence to support the applicability of the growth efficiency hypothesis in an alpine grassland ecosystem.

Beschreibung: A gravity network with 302 observation points has been established in the western Sichuan Foreland Basin (SFB) to explore Bouguer gravity anomalies (BGAs). Our observational results reveal that the BGAs are negative as a whole, with a maximum value of −220 mGal (10 −5 m s −2 ) at the northwest region of the study area. The real Moho depths beneath the SFB revealed by BGA data change smoothly from 39.5 km in the southeast to 43.7 km in the northwest of the monitoring region. However, the isostatic ones deduced from Airy isostatic model and topographical data vary approximately 39.5–42.0 km. The maximum differences of 2.7 km between the real and isostatic Moho depths are found near the seismic gap between the M 8.0 Wenchuan and M 7.0 Lushan earthquakes, where the crust is in the greatest isostatic imbalance of the monitoring region. Analysis of the isostatic state indicates that the deep dynamic environment near the seismic gap between these two earthquakes indicates an M  ≥ 7.0 earthquake in the future. This study indicates that we can use isostasy as a potential approach to study the dynamic process of crustal material movement and to analyze regional potential seismic risks.

Beschreibung: Climate change is considered a top threat to biodiversity, but the relative roles of contemporary climate versus the rate of climate change in determining spatial patterns of biodiversity are far from clear. China has a very diverse flora and harbors a high percentage of endemic species, but the mechanisms underlying spatial patterns of plant endemism are poorly understood. This study explores the geographical patterns of a representative sample of 555 endemic seed plant species at the scale of 0.5° latitude × 0.5° longitude. Ordinary least squares and spatial autoregressive models were compared to assess the relationship between richness of endemics and the rate of climate change in the past century, as well as a group of contemporary climate variables. In China, a high level of endemism was associated with high elevation and low rate of climate change. However, contemporary climate had a stronger impact than climate change velocity in the past century on endemic species richness patterns. Specifically, mean annual precipitation and annual range of temperature were important contemporary climatic factors. The rate of change of annual mean temperature, but not that of annual precipitation, also significantly contributed to the spatial pattern of plant endemic species richness. We found no significant relationship between topographic variation and endemic species richness, while temperature variability at multiple time scales was strongly correlated with the species richness pattern. Future work should consider the direction of climate change and incorporate higher-resolution data.

Beschreibung: Widespread lakes on the Tibetan Plateau (TP) are valuable archives for investigating climate and environment changes, which could provide essential information on the mechanisms of past climate changes on the TP and their interaction with the global climate systems. However, there is a lack of in-depth investigation of modern limnological processes in the Tibetan lakes, which hampers the understanding of paleolimnological records and lake ecosystem succession. In this study, we performed continuous temperature monitoring at two lakes, Bangong Co, a freshwater lake in the western TP, and Dagze Co, a brackish lake in the central TP, in order to characterize the patterns of seasonal temperature variability, stratification, and mixing. Temperature data for an entire hydrological year demonstrate that Bangong Co is a dimictic lake and that Dagze Co is a meromictic lake. The higher salinity in the deep water at Dagze Co prevents the lake from overturning completely, and this finding is supported by simulations using a physical limnological model Lake Analyzer. Continuous lake water temperature monitoring provides fundamental data for classifying Tibetan lakes, as well as the hydrological basis for understanding their paleolimnological records and ecosystem succession.

Beschreibung: An 18-year long (1993–2011) comprehensive dataset of snow and meteorological variables from Col de Porte, France is used to analyze the variation of shortwave broadband albedo with elapsed time after snowfalls (snow aging) during each snow season. The effects of air temperature, snow surface temperature and snow depth on snow albedo are investigated. An index based on the accumulation of air temperature over several consecutive days with daily mean higher than 2.5 °C is proposed to divide each snow-covered period into a dry and the following wet snow season when this index reaches 18 °C. The results indicate that snow surface albedo decreases exponentially with time in both dry and wet snow seasons. Snow albedo reduction with snow aging is small at low surface temperature and the reduction rate increases with the rise of surface temperature. However, the reduction rate is widely scattered within the observed range of temperature, implying a loose relationship between snow albedo and snow surface temperature. Snow albedo in wet snow season is generally smaller and decreases faster than in dry snow season. For Col de Porte site, snow depths to effectively mask the underlying surface are 21 and 33 cm in dry and wet snow season respectively.

Beschreibung: The rareness and inhomogeneity of the data points cause difficulties in the reconstruction of past average temperature. Optimal regional averaging is a method that can overcome these difficulties and obtain the average temperature of target area by means of optimal weights using limited temperature data. In this paper, the average temperature in the Northern Hemisphere is calculated by the optimal regional averaging method using two types of data: temperature data from Climatic Research Unit from 1901 to 2000 and maximum latewood density dataset of tree from 1500 to 1949. Five, ten, fifteen data points from CRU and forty data points from MXD are used in our research. The results show that even with the relatively less data used in this reconstruction, the method allows the reconstruction of the average temperature of the Northern Hemisphere more accurately, which provides the temperature information for palaeoclimate reconstruction.

Beschreibung: Using in situ observations from THEMIS A, D and E during the 2008–2011 tail season, we present a statistical study of the evolution of pressure gradients in the near-Earth tail during bursty bulk flow (BBF) convection. We identified 138 substorm BBFs and 2,197 non-substorm BBFs for this study. We found that both the pressure and the B Z component of the magnetic field were enhanced at the arrival of BBFs at the spacecraft locations. We suggest that the increase of B Z during non-substorm BBFs is associated with flux pile-up. However, the much stronger enhancement of B Z during substorm BBFs implies the occurrence of magnetic field dipolarization which is caused by both the flux pile-up process and near-Earth current disruption. Furthermore, a bow-wave-like high pressure appears to be formed at the arrival of substorm BBFs, which is responsible for the formation of region-1-sense FACs. The azimuthal pressure gradient associated with the arrival of substorm BBFs lasts for about 5 min. The enhanced pressure gradient associated with the bow wave is caused by the braking and diversion of the Earthward flow in the inner plasma sheet. The results from this statistical study suggest that the braking and azimuthal diversion of BBFs may commonly create azimuthal pressure gradients, which are related to the formation of the FAC of the substorm current wedge.

Beschreibung: A series of novel imidazolium oxidative-thermoregulated bifunctional ionic liquids (ILs) have been synthesized by introducing the thermoregulated structural unit into imidazolium cation and using heteropolyanion as the anion of ILs. The structures of these new type of task-specific ionic liquids (TSILs) are characterized by FT-IR and 1 H NMR. The thermostability of ILs is analyzed by thermogravimetry. The thermoregulated properties of ILs in aqueous and organic solvents are mainly investigated. These ILs have the corresponding cloud points (CPs) in aqueous. The effects of IL concentration, polymerization degree, inorganic additives and organic additives on the CP are studied. IL/DMF/ n -heptane or n -octane biphasic system has the corresponding critical solution temperature (CST), and has the feature of “homogeneous at high temperature, heterogeneous at low temperature”. The effects of IL dosage and polymerization degree on the CST are given. IL/DMF/ n -octane thermoregulated biphasic system has been successfully applied for catalytic oxidative desulfurization of model fuels. This study opens up a new way for catalytic oxidation to achieve an integration of homogeneous catalysis and heterogeneous separation.

Beschreibung: High-rate GPS data from the United States continuously operating reference stations in the Alaska region are processed using the recently developed precise point positioning (PPP) technique. The traditional PPP technique does not fix ambiguities into their integers because these ambiguities do not have an integer nature when data from a single receiver, as well as precise orbit and clock corrections, are used. Additional corrections, i.e., uncalibrated phase delay (UPD), are needed to fix integer ambiguities and consequently improve positioning accuracy. This study proposes a methodology to compute for wide-lane and L2 (the second L-band frequency) UPDs using the geometry-based model and subsequently applies these parameters to the computation for ambiguity-fixed solutions. The instantaneous displacements of near-field sites, as well as the permanent deformations after the earthquake, are therefore obtained for the January 5, 2013, Alaska earthquake. The real-time performance of PPP solutions are assessed by considering realistic data latency and data interval of corrections. Ambiguity-fixed solutions are compared with ambiguity-float ones. The comparison shows that the positioning accuracy can be improved significantly when the ambiguities are fixed correctly. The solutions using the real-time corrections are also compared with those using post-processing corrections, i.e., Center for Orbit Determination in Europe final orbit and clock. Although the accuracy is somehow degraded because of the data latency and data interval, the real-time results are satisfactory for use in monitoring the small-scale deformation (1–2 cm) caused by the Alaska earthquake. In addition, the kinematic ambiguity-fixed PPP solutions for 7 days around the earthquake are calculated to obtain permanent pre- and post-earthquake deformations. The deformations computed from real-time and post-processing corrections do not appear to be significantly different.

Beschreibung: Investigation of temporal variations in the stable δ 18 O and δ D isotopes from Kathmandu’s precipitation events shows that the relatively enriched δ 18 O and δ D values in the winter (the dry season, dominated by the westerlies) were positively correlated with temperature, indicating a temperature effect controlling the changes of δ 18 O and δ D. However, the δ 18 O and δ D values were depleted in the summer (the wet season, dominated by the Indian monsoon), which were negatively correlated with precipitation amount, indicating an amount effect. In addition, the comparison of stable isotopes in precipitation from Kathmandu and Mawlong (near the Bay of Bengal) shows that the overall trends of δ 18 O and δ D values at Kathmandu generally approximate those at Mawlong. However, there remain many differences between the details of the isotopic changes at Kathmandu versus those at Mawlong. Compared with those at Mawlong, the further rainout effect and the more intense lift effect of the oceanic moisture by the high mountains resulted in the more depleted δ 18 O and δ D values in summer precipitation at Kathmandu. A deuterium excess and the local meteoric water lines reveal that evaporation at Kathmandu exceeds that at Mawlong. The data also show that the Indian monsoon activities at Mawlong are more intense than those at Kathmandu.

Beschreibung: Occlusion of carbon (C) within phytoliths (PhytOC) is becoming one of the most promising terrestrial C sequestration mechanisms. This study explored the production of PhytOC within 35 bamboo species belonging to three ecotypes using methods of microwave digestion. The aim of this study is to explore the present and potential C sequestration rate within phytoliths of bamboo species from three ecotypes. PhytOC content in bamboos of three ecotypes ranges from 0.07 % to 0.42 %. The mean PhytOC production flux decreases as: clustered bamboo (0.050 ± 0.016 t CO 2 ha −1  a −1 ) ≈ mixed bamboo (0.049 ± 0.016 t CO 2 ha −1  a −1 ) 〉 scattered bamboo (0.038 ± 0.020 t CO 2 ha −1  a −1 ). The phytolith carbon sequestration in Chinese bamboo is estimated to be 0.293 ± 0.127 Tg (1 Tg = 10 12  g) CO 2 a −1 ; approximately 75 %, 3 %, and 22 % of which is contributed from scattered, mixed and clustered bamboo, respectively. Taking the PhytOC production flux of 0.18 ± 0.12 t CO 2 ha −1  a −1 and current annual area increasing rate of 3 %, global bamboo phytoliths would sequester 11.9 ± 7.9 Tg CO 2 a −1 by 2050. Consequently, bamboo forests have significant potential to mitigate the increasing concentration of atmospheric CO 2 by maximizing PhytOC production flux and expanding bamboos.

Beschreibung: N-type Si (111) wafers have been processed by high-current pulsed electron beam (HCPEB) treatment with an increasing number of irradiation (1, 10 and 20 pulses). The results of this work show that a highly porous nanostructure was formed after irradiation. Moreover, the high-density Si nanocrystals (Si-ncs) about 3 nm were distributed on the surface of Si wafers and exhibited 3.02 eV Photoluminescence (PL) emission in blue band. The PL intensity increases with the increase in the Si-ncs’ density in accordance with the quantum confinement model, which can be ascribed to the different pulse time of HCPEB treatment. The possible formation mechanisms of micropores and Si-ncs are discussed.

Beschreibung: The effective adsorption capability of a hydrogenated graphene (H-Gr) was demonstrated. The H-Gr was firstly prepared by heating graphene (Gr) in a hydrogen flow at 1,000 °C. The specific surface area, layer number, zeta potential, surface defects, surface compounds groups and elemental ratio of H-Gr were investigated. Taking 2,4-dichlorophenol as a target pollutant, the adsorption ability of H-Gr was evaluated. The results showed that the adsorption kinetics followed the pseudo-second-order equation well. For the adsorption isotherms, the equilibrium data of H-Gr were found to fit to Langmuir model, which was different from the Freundlich model of Gr. The adsorption capacity of H-Gr was high to 287.01 mg/g, almost three times as much as that of Gr, which was benefit from the increase of specific surface area and zeta potential. This work suggests that H-Gr may be a potential candidate for the adsorption of aromatic compounds from water and has great prospect for practical application.

Beschreibung: Two consecutive magnetic flux ropes, separated by less than 30 s ( Δt  〈 30 s), are observed within one magnetic reconnection diffusion region without strong guide field in the Earth’s magnetotail by Cluster multi-spacecraft. The flux ropes are characterized by bipolar signatures of the south–north magnetic field component B z accompanied with strong core magnetic field B y , intense current J and density depletions inside of them. In spite of the small but non-trivial global scale negative guide field (– B y ), there exists a directional change of the core fields of two flux ropes, i.e., − B y for the first one, and + B y for the second one. The directions of the core fields are the same as the ambient cross-tail magnetic field component ( B y ) just outside of flux ropes. Therefore, we suggest that the core field of flux ropes is formed by compression of the local preexisting B y and that the directional change of core field is due to the change of local preexisting B y . Such a change in ambient B y might be caused by some microscale physics.

Beschreibung: In this work, a series of new metal phosphonates were hydrothermally synthesized and structurally characterized based on m -xylylenediphosphonic acids (H 4 L), including [M(H 2 L)(bpy)] (M = Mn 1 , Co 2 ), [MH 2 L)(phen)] (M = Co 3 , Cu 4 ), and [Cu 2 (H 2 L) 2 (bpy″) 2 ] 5 (bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, bpy″ = 4,4′-dimethyl-2,2′-bipyridine). X-ray diffraction indicated that compounds 1 and 2 were isomorphic. Complexes 3 and 4 were shown to crystallize in different space groups but had similar crystallographic units. In the complexes, H 4 L was seen to partially deprotonate to afford H 2 L 2− . The H 2 L 2− ligands in 1 – 4 functioned as tetradentate ligands with each phosphonate group adopting bidentate coordination mode with two M centers to generate a 2D layer. In addition, the H 2 L 2− anions in 5 functioned as tridentate ligands with one phosphonate group adopting the bidentate mode and another phosphonate group adopti ng the monodentate mode, thus linking three Cu atoms to provide a 1D chain. The IR and thermal stabilities of these compounds were subsequently examined.

Beschreibung: Identifying melts of thickened lower continental crust from high Sr/Y rocks is very important to trace deep crustal processes. Recent studies on Dabie Early Cretaceous granitoids have revealed that melts derived from thickened lower continental crust have higher Sr/CaO ratios and define a high Sr evolution trend compared with normal granitoids. Fractional crystallization of plagioclase can significantly change Sr and CaO contents of melts, but its role in controlling the Sr/CaO ratios of the melts is still unclear. This study gives a direct comparison of plagioclase compositions between normal granitoids and low-Mg adakitic rocks. On the basis of Sr–Ca exchange partition coefficient, discussions on effect of plagioclase crystallization on Sr/CaO ratios of melts show that fractional crystallization of abundant plagioclase cannot significantly change Sr/CaO ratios of granitic melts, which are inherited from their individual initial melts. High Sr/CaO ratios indicate the absence of plagioclase in sources of granitic melts. Therefore, high Sr/CaO correlation can be an important indicator to identify melts derived from thickened lower continental crust.

Beschreibung: In the present study, the Ti-in-biotite geothermometer was revised using more than 300 natural rutile- or ilmenite-bearing metapelites collected worldwide. The formulation was empirically calibrated as \( \ln [T\,(^\circ {\text{C}})] = 6.313 + 0.224\ln (X_{\text{Ti}} ) - 0.288\ln (X_{\text{Fe}} ) - 0.449\ln (X_{\text{Mg}} ) + 0.15P\,({\text{GPa}}) \) , with \( X_{j} = {{j}}/({\text{Fe}} + {\text{Mg}} + {\text{Al}}^{\text{VI}} + {\text{Ti}}) \) in biotite, assuming ferric iron content of 11.6 mol% of the total iron in biotite. This thermometer is consistent with the well-calibrated garnet–biotite thermometer within error of ±50 °C for most of the calibrant samples and can successfully distinguish systematic temperature changes of different metamorphic zones in both prograde and inverted metamorphic terranes as well as thermal contact aureoles. Thus, the thermometer truthfully reflects real geologic conditions and can be applied to TiO 2 -saturated metapelites metamorphosed at the crustal level within the calibration ranges (450–840 °C, 0.1–1.9 GPa, X Ti  = 0.02–0.14 in biotite).

Beschreibung: This introductory article starts by describing the genesis of this special issue and the interconnection of its topics. The editors offer a variety of reading entries into the key-note articles and responses. The article reconstructs the research interests underpinning the idea of integrating meaningfulness, volunteers and citizenship. It highlights the explicit interdisciplinary design of the special issue, and shows how the key-note authors, and their respondents, weave connections between meaningfulness, volunteering and citizenship. And, finally, the editors bring the background understandings of the key-note papers to the foreground, and reconstruct a non-intentional meta-level discussion on two fundamental concepts and their interplay: self and world.

Beschreibung: This article argues, firstly, that voluntary civic practices are not doomed to fall prey to a Big Society rhetoric and a cynical politics of cuts in social spending. It all depends on how these civic practices are promoted and what kind of civic discourse is communicated through the channels of social media and public opinion. Secondly, the author highlights the political importance of connecting meaningfulness with citizenship.

Beschreibung: This paper draws on an in-depth phenomenological analysis of some interviews taken from volunteers, inviting them to reflect on their lived experiences of meaningfulness in the context of volunteering and citizenship. It is found that while some testimonies reinforce the standard conceptions of meaningfulness, other testimonies vary from it. The main challenge of this contribution consists in phenomenologically describing this alternative picture of meaningfulness, depicted as the event of wit(h)nessing. In a final part, the authors consider how volunteering is at times especially prone to further experiences of wit(h)nessing.

Beschreibung: Biodiesel production from non-edible feedstocks is currently drawing much attention due to legitimate concerns about the effects of using edible oil for fuel. Pangium edule Reinw is a non-edible feedstock. Pangium is a tall tree native to the Micronesia, Melanesia and the mangrove swamps of South-East Asia. In this study, biodiesel production and characterization from P. edule oil was reported. The seeds were obtained from Bogor, Indonesia. The oil was found to have an acid value of 19.62 mg KOH/g oil. Therefore, a two-step acid–base-catalysed transesterification was used to produce biodiesel. This was followed by evaluating the physical and chemical properties of biodiesel and its blends with diesel. It has been found that the determined properties of P. edule methyl ester indicate that the oil can be considered as a future biodiesel source. The most remarkable feature of P. edule is its cloud, pour and cold filter plugging points. This biodiesel yielded cloud, pour and cold filter plugging points of –6, –4 and –8 °C, respectively. This indicates the viability of using this biodiesel in cold countries. Therefore, it is suggested that more research should be conducted on P. edule for future biodiesel production.

Beschreibung: The paper presents a new Kernel-based monitoring algorithm compared with statistical process control methods, such as DISSIM and MS-PCA and some others methods widely used in process control applications. The proposed algorithm is a modified version of the well known support vector domain description (SVDD). The last one is commonly used for one-classification problems, named also novelty detection. In this paper, we have used a modified SVDD endowed with useful tools to manage multi-classification problems. The proposed classifier is also able to deal with stationary as well as non-stationary data. The principle is based on the dynamic update of the training set through a recursive deletion/insertion procedure according to adequate rules. In order to reduce the computational complexity and improve the rapidity of convergence, the algorithm considers in each run a limited frame of samples for the training process. To prove its effectiveness, the approach is assessed at first on artificially generated data. Then, we have performed a case study applied on chemical process.

Beschreibung: A series of nonionic surfactants were synthesized from gallic acid and polyethylene glycols with different molecular weights. Chemical structures of the surfactants were confirmed using elemental analysis, infrared and nuclear magnetic resonance ( 1 H-NMR) spectroscopy. Surface activities of the surfactants in their solutions were determined by surface tension measurements. Increasing the polyethylene glycol chain length increased the surface activity of the surfactants in solutions. Measurements of interfacial tension between surfactants solutions and substrates with different polarity showed that the type of substrates plays functioning role on the interfacial properties. Thermodynamic properties of adsorption and micellization processes showed their tendency towards adsorption at solution interface and micellization in their solutions. Results showed reasonable surface activities compared to conventional nonionic surfactants.

Beschreibung: Compressed sensing for multiple input multiple output (MIMO) radar can potentially enhance spatial resolution and improve jamming noise suppression capability by making use of information about the sparse “scene.” In this paper, an efficient method for anti-jamming in MIMO chaotic radar direction finding of point-like targets is proposed. The novelty of this paper is that it capitalizes on chaotic coded waveform to construct measurement operator, which shows a low correlation with jamming noise; therefore, the proposed approach can take advantage of the sparse optimization method to suppress jamming noise of the received signals. A directional optimization algorithm based on gradient pursuit is implemented in reconstruction of the sparse “scene.” The performances of the proposed approach are evaluated via computer simulation studies and shown to outperform conventional methods.

Beschreibung: This paper presents the implications of the adjustable fountain wave soldering process during pin through hole (PTH) component assembly process. The PTH vertical fill was carried out experimentally by using a newly developed adjustable fountain wave soldering machine ( \({0^{\circ}}\) conveyor angle). A similar printed circuit board and components were assembled by using a conventional wave soldering machine ( \({6^{\circ}}\) conveyor angle). This paper focuses on vertical filling by using both wave soldering methods. A non-destructive X-ray computed tomography scanning machine was employed to inspect the vertical fill of each PTH. The percentage of the vertical fill for two different wave soldering machines was analyzed. The PTH filling phenomenon during wave soldering was also discussed. FLUENT software was utilized to simulate the PTH vertical filling of adjustable fountain wave soldering. The volume of fluid model tracked the flow front of the molten solder. The simulation and experimental results showed a nearly identical solder filling profile. The void of the PTH vertical filling was also visualized under an X-ray CT scanning machine.

Beschreibung: Mechanical alloying was employed to synthesize Al–Zn–Mg–Cu alloys with nickel additives from elemental powders via high-energy ball milling. The milled powders were cold compacted and sintered thereafter. The sintered compacts underwent homogenization treatments at various temperature conditions and aged at 120 °C for 24 h (T6). Subsequently, the compacts were retrogressed at 180 °C for 30 min and re-aged at 120 °C for 24 h (RRA). The milled powders and heat-treated products were characterized via X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive spectroscopy. The crystallite sizes and micro-strains of the alloy powder were estimated with the broadening of XRD peaks by using the Williamson–Hall equation. The results show that Zn, Mg, and Cu atoms are soluble in the Al matrix after milling for 5 h. The Vickers hardness of Al alloys was enhanced following retrogression and re-aging treatments. The addition of nickel influenced the hardness of the compacted powders.

Beschreibung: Many fiber types are used in fiber-reinforced concrete (FRC) pavements. The maximum undamaged defect size ( d max ) concept has been applied to predict notch-based fracture in different types of concrete. The present paper applies this concept to different types of FRC pavement, namely, glass fiber-reinforced concrete pavement and steel fiber-reinforced concrete pavement. Due to the quasi-brittle manner of concrete, various fracture models have been developed to study the crack propagation in the pavement structures. The fracture energy was determined based on the recommendation of the RILEM Committee 50-FMC. An experimental study was carried out to investigate the effect of adding short fiber, steel or glass, in controlling the fracture energy of concrete. The analysis was invoked for constant fiber length of 25mm. The flexure test of single-edge notched and unnotched specimens was performed using three-point bending configuration. Four different values of crack-depth ratios were considered, mainly, 0.00, 0.10, 0.25, and 0.40. Experimental results showed that the calculated d max based on RILEM Committee 50-FMC is greater than the maximum aggregate size (MAZ). This means that there is no compatibility between the flexural strength of FRC and its fracture energy calculated based on RILEM Committee 50-FMC. Therefore, a modified calculation of the area of load-deflection curve was suggested to improve the reliability of fracture energy measured based on RILEM Committee 50-FMC. It is found based on this modification that d max is less than 0.7 MAZ.

Beschreibung: Advances in research and development of geopolymer concrete have made it a feasible alternative material for civil and infrastructural applications. However, currently, there is a gap in design methodology due to lack of knowledge on geopolymer concrete, which has been a significant barrier for engineers and designers. The current research addresses this gap, modeling an equivalent stress block of fly-ash-based geopolymer concrete, to enable the design of sections. It was found that the design parameters based on the standard codes are not well suited for the fly-ash-based geopolymer concrete structures. In addition, the elastic modulus model obtained from Ordinary Portland Cement concrete is inappropriate for fly-ash-based geopolymer. Therefore, in this study, the stress–strain relation, an elastic modulus model and equivalent stress block design parameters were obtained from experimental results, also using prior published data, for flexural strength predictions of fly-ash-based geopolymer concrete members. A simplified stress–strain relationship based on Thorenfeldt’s model, as well as the stress block design equations, was fit to test data. The results showed that the simplified stress–strain model is reasonably accurate. The prediction of flexural moment capacity based on the proposed design parameters correlated well with experimental test data. It was found that the nominal moment capacity using standard code design parameters was about 1.43 times higher than with the proposed design parameters.

Beschreibung: Radio frequency spectrum is too crowded and expensive to install new broadband channels. Free space optical (FSO) communication is a viable technology, which offers enormous bandwidth, license-free spectrum and non-interfering nature. But the FSO link deteriorates significantly due to the atmospheric turbulence and sever weather conditions (fog, cloud and snow). Hybrid FSO/RF communication system with independent coding scheme has been suggested in the literature. But such systems are expensive and have synchronization issue. We propose a hybrid FSO/RF communication system with joint coding scheme. A novel puncturing optimization algorithm is developed, which adaptively tackle fading effects of the individual communication link. The proposed puncturing algorithm gives more than 3 dB power gain over the fixed system.

Beschreibung: The nature of microbial communities and their relation to enzyme activities in the Taptapani hot spring Odisha, India, is a neglected area of investigation. To address this, the microbial diversity, enzyme activities and the physicochemical factors of the hot spring water were studied. Organisms were identified using the 16S rDNA, 28S rDNA and 18S region of rDNA for bacteria, fungi and algae, respectively, after amplification by the polymerase chain reaction. Phylogenetic analysis of the sequenced gel electrophoresis bands revealed a great diversity of microorganisms. Based on morphology, nine groups of bacteria, three groups of fungi and four groups of algae were dominant during all seasons. The growth behavior of the selected isolates was studied at different elevated temperatures which revealed that all ten isolates (six bacteria, three fungi and one alga) were able to grow in the temperature range of 50–80°C and at pH 4–9. Maximum temperature and pH for the amylase activity were found to be 80 and 9°C, respectively, while an optimum amylase activity was observed at 60°C and pH 9. Considerable activity was observed at both acidic and alkaline pH (4.0–10.0), suggesting wide technical applications for these enzymes and indicating that these enzymes are novel.