Pathways for sustainable technology development : The case of bicycle mobility in Berlin

Sustainability requires that quality of life and resource consumption are harmonized. The use of sustainable technologies fosters their harmonization. A scenario based method has been developed for identifying sustainable technology systems on different levels of development and in different areas of human living. The developed method consists of four elements: the surrounding field scenarios, technology pool, sustainability assessment and system creation. They can be applied in various paths with different starting points. The two technology induced paths, emanating from either a system or a system element, enable the transformation of technological potentials into useful applications. The problem induced path, emanating from future framework conditions of an observed field, allows human needs to be satisfied trough technological potentials. The application shown in this paper illustrates the usage of the method's problem induced path in mobility as one area of human living. Based on three surrounding field scenarios for bicycle mobility in Berlin, technology systems for bicycle design, operation and their repair in self-help workshops are illustrated

Synthesis and Properties of Bis(nitrocarbamoylethyl) Nitramine - A New Energetic Open-Chain Nitrocarbamate

The nitrocarbamate derivative of the well-known and intensively investigated nitro ester DINA was prepared and studied. Starting with bis(hydroxyethyl) nitramine obtained from DINA, the corresponding carbamate was obtained by treatment with chlorosulfonyl isocyanate (CSI). Using fuming nitric acid only as nitration reagent, the target compound bis(nitrocarbamoylethyl) nitramine was synthesized. Furthermore, a route to the salt bis(nitrocarbamoylethyl)ammonium nitrate by a simple two step synthesis starting from diethanolamine was revealed. The compounds were fully characterized by NMR spectroscopy, X-ray diffraction, differential thermal analysis, vibrational analysis and elemental analysis. The sensitivities towards impact and friction of the energetic compounds were measured, as well as their energetic properties determined by using the energies of formation, calculated on the CBS4-M level of theory, with the EXPLO5 computer code

Performance of TKX‐50 in thermobaric explosives

In this study, the behavior of the high-nitrogen compound TKX-50 in model thermobaric formulations was investigated. The addition of 10 % Al to TKX-50 reduces the heat of detonation by approximately 90 J/g. Despite this, Al reacts with the detonation products of TKX-50 in an exothermic manner, and the energy contribution was calculated to be approx. 375 J/g. In addition, the overpressure in the explosion chamber filled with argon after detonation of aluminized TKX-50 charges containing 27 % Al is approx. 20 % higher than in the case of neat TKX-50. Also the maximum temperature of the TKX-50/Al explosion products in the argon filled chamber is higher by 370 K than that of measured after detonating TKX only. What is more aluminum oxynitride with a low nitrogen content has been identified in the solid detonation products of aluminized TKX-50, but only for detonations in argon. Of course, charges made of TKX-50/Al mixture generate significantly higher overpressure and radiant temperature values in a confined space when they are detonated in an air atmosphere. It all means that burning aluminum in nitrogen provides little energy, and even if the concentration of nitrogen in the post-detonation products is much higher than that of oxygen, aluminum oxides are preferentially formed

Investigation and Characterization of Nitrazapropane‐, Oxapropane‐ and Trinitrazaheptane‐Bridged Nitro Esters

In this work, 1,3-dinitroxy-2-nitrazapropane and 1,7-dinitroxy-2,4,6-trinitrazaheptane were synthesized and investigated. Starting from hexamine, the open-chain compounds were prepared by a modified Bachmann procedure which is commonly used for the synthesis of hexogen (RDX) and octogen (HMX). All new compounds were characterized by NMR spectroscopy, X-ray diffraction, vibrational analysis and elemental analysis. Their thermal behavior was studied by differential thermal analysis (DTA) and thermogravimetric analysis (TGA). The sensitivities towards impact (IS) and friction (FS) were determined according to the BAM (Bundesanstalt für Materialforschung und -prüfung) standard method. Their energetic properties, which were determined from the energies of formation at the CBS-4 M level, were calculated using the EXPLO5 computer code. Moreover, 1,3-dinitroxy-2-oxapropane was synthesized and investigated. The various compounds were compared with each other and with the commonly used explosives in terms of their physicochemical properties and detonation behavior

Synthesis of Bridged Tetrazoles with Promising Properties and Potential Applications by a One‐Step Finkelstein Reaction

Numerous nitramine bridged compounds which show promising combinations of properties have already been identified in the area of energetic materials. In this work, four new nitrazapropane bridged tetrazoles, as well as four new trinitrazaheptane tetrazoles and three oxapropane bridged tetrazoles were synthesized and fully characterized. These new compounds can all be synthesized by a simple, one-step synthesis using Finkelstein conditions. All of these new energetic materials were characterized using NMR spectroscopy, single crystal X-ray diffraction, vibrational analysis and elemental analysis. The thermal behaviour of these compounds was studied by differential thermal analysis (DTA) and partly by thermogravimetric analysis (TGA). The BAM standard method was used to determine the sensitivities towards impact (IS) and friction (FS). The enthalpies of formation were calculated at the CBS-4M level, and the energetic performances were calculated using the EXPLO5 (V6.06.01) computer code. The properties of the new compounds were compared to each other as well as to the known energetic material RDX. Moreover, the iron(II) and copper(II) perchlorate complexes with 1,3-bis-1,1-tetrazolylnitrazapropane as ligand were prepared and investigated

Genomic prediction in CIMMYT maize and wheat breeding programs

Genomic selection (GS) has been implemented in animal and plant species, and is regarded as a useful tool for accelerating genetic gains. Varying levels of genomic prediction accuracy have been obtained in plants, depending on the prediction problem assessed and on several other factors, such as trait heritability, the relationship between the individuals to be predicted and those used to train the models for prediction, number of markers, sample size and genotype × environment interaction (GE). The main objective of this article is to describe the results of genomic prediction in International Maize and Wheat Improvement Center's (CIMMYT's) maize and wheat breeding programs, from the initial assessment of the predictive ability of different models using pedigree and marker information to the present, when methods for implementing GS in practical global maize and wheat breeding programs are being studied and investigated. Results show that pedigree (population structure) accounts for a sizeable proportion of the prediction accuracy when a global population is the prediction problem to be assessed. However, when the prediction uses unrelated populations to train the prediction equations, prediction accuracy becomes negligible. When genomic prediction includes modeling GE, an increase in prediction accuracy can be achieved by borrowing information from correlated environments. Several questions on how to incorporate GS into CIMMYT's maize and wheat programs remain unanswered and subject to further investigation, for example, prediction within and between related bi-parental crosses. Further research on the quantification of breeding value components for GS in plant breeding populations is required.J Crossa, P Pérez, J Hickey, J Burgueño, L Ornella, J Cerón-Rojas, X Zhang, S Dreisigacker, R Babu, Y Li, D Bonnett and K Mathew

Heterotic Trait Locus (HTL) Mapping Identifies Intra-Locus Interactions That Underlie Reproductive Hybrid Vigor in Sorghum bicolor

Identifying intra-locus interactions underlying heterotic variation among whole-genome hybrids is a key to understanding mechanisms of heterosis and exploiting it for crop and livestock improvement. In this study, we present the development and first use of the heterotic trait locus (HTL) mapping approach to associate specific intra-locus interactions with an overdominant heterotic mode of inheritance in a diallel population using Sorghum bicolor as the model. This method combines the advantages of ample genetic diversity and the possibility of studying non-additive inheritance. Furthermore, this design enables dissecting the latter to identify specific intra-locus interactions. We identified three HTLs (3.5% of loci tested) with synergistic intra-locus effects on overdominant grain yield heterosis in 2 years of field trials. These loci account for 19.0% of the heterotic variation, including a significant interaction found between two of them. Moreover, analysis of one of these loci (hDPW4.1) in a consecutive F2 population confirmed a significant 21% increase in grain yield of heterozygous vs. homozygous plants in this locus. Notably, two of the three HTLs for grain yield are in synteny with previously reported overdominant quantitative trait loci for grain yield in maize. A mechanism for the reproductive heterosis found in this study is suggested, in which grain yield increase is achieved by releasing the compensatory tradeoffs between biomass and reproductive output, and between seed number and weight. These results highlight the power of analyzing a diverse set of inbreds and their hybrids for unraveling hitherto unknown allelic interactions mediating heterosis

Pitfalls of predicting complex traits from SNPs

The success of genome-wide association studies (GWASs) has led to increasing interest in making predictions of complex trait phenotypes, including disease, from genotype data. Rigorous assessment of the value of predictors is crucial before implementation. Here we discuss some of the limitations and pitfalls of prediction analysis and show how naive implementations can lead to severe bias and misinterpretation of results