Methane emissions from end-use installations in residential natural gas systems remain poorly quantified, despite their importance to both safety and climate policies worldwide. While distribution networks and appliances have received research attention, interior piping between the meter and appliances represents a critical knowledge gap. To address this gap, a systematic survey of 473 residential systems in Saarlouis, Germany, was conducted using standardized pressure decay tests (DVGW G 600). Measurements were performed during the installation of gas regulators necessitated by a grid pressure increase from 23 mbar to 55 mbar above ambient. This provided a unique opportunity to assess whole-system leakage under controlled conditions without installation modifications. Leak rates were standardized to reference pressure and converted to methane emissions using measured gas composition, using a linear pressure scaling as a provisional approximation valid for the small pressure differences in the applied test conditions. A total of 411 (86.9%) installations showed no detectable leak rate (LDL: 0.2 Lh−1). However, seven systems (1.5%) exceeded 1 Lh−1, and one surpassed the unacceptable threshold of 5 Lh−1. Mean emissions across all systems were 0.067 [0.041, 0.098] gh−1, with smaller installations showing higher volume-normalized rates. Critically, fewer than 1.48% of systems contributed more than 46% of total emissions, demonstrating a strongly skewed, heavy-tailed distribution. Scaled nationally using Monte Carlo methods accounting for sampling uncertainty and skewed distributions, residential interior piping contributes 12.30 [8.11, 18.55] Ggyear−1 to Germany’s methane emissions. These results emphasize the need to include residential leak rates in emission inventories and highlight the efficiency potential of targeted mitigation strategies focused on high-emitting installations under evolving EU methane regulations.

Spezifische, unregelmäßige Anordnungen von Gold-Nanokristallen mit Durchmessern von 5 und 10 nm lassen sich gezielt mit Hilfe doppelsträngiger DNA als Templat herstellen (siehe Bild; A′ und B′ bezeichnen die zu den Sequenzen A bzw. B komplementären Oligonucleotidsequenzen). Die hier beschriebenen Methoden sollten sich auf Nanokristalle aus den verschiedensten Materialien anwenden lassen.

At least one large-body (diameter > 1.1 km) hypervelocity cratering event occurred during ~ 0.8-0.90 Ma (Zhamanshin, Kazakhstan) in the Middle Pleistocene Transition period. Analysis designed to reduce uncertainty in the dimensions of the Zhamanshin structure employing high resolution topography demonstrated that it likely generated a ~ 26.5 km diameter multi-ring crater. This is at least two times larger than the current best estimates. Using a range of accepted impactor sizes, velocities, compositions, and angles of impact, such impacts typically yield kinetic energies of impact over 240,000 Megatons (TNT). Explosive energetic events of this magnitude (e.g., Yellowstone Caldera) at other times (K-Pg) have created global environmental effects. The factor of two discrepancy in the dimensions of Zhamanshin increases the kinetic energy yield by factors of 7-10, with significantly larger environmental consequences. This justifies examination of rapid climate transitions linked to biological consequences, including those related to environmental perturbations, at ~0.9 Ma.

From the contents: Growth of Nanocrystals.- Energy States.- Dielectric Effects.- Mechanisms of Dephasing.- Trap Processes.- Effects of Static External Fields.- Nanocrystals of III-V Compounds.- Nanocrystals of Indirect-Gap Materials Concepts of Applications.

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTKinetics of II-VI and III-V Colloidal Semiconductor Nanocrystal Growth: "Focusing" of Size DistributionsXiaogang Peng, J. Wickham, and A. P. AlivisatosView Author Information Department of Chemistry, University of California Berkeley and Materials Sciences Division Lawrence Berkeley National Lab Berkeley, California 94720-1460 Cite this: J. Am. Chem. Soc. 1998, 120, 21, 5343–5344Publication Date (Web):May 14, 1998Publication History Received18 February 1998Published online14 May 1998Published inissue 1 June 1998https://pubs.acs.org/doi/10.1021/ja9805425https://doi.org/10.1021/ja9805425rapid-communicationACS PublicationsCopyright © 1998 American Chemical SocietyRequest reuse permissionsArticle Views22646Altmetric-Citations1691LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Cadmium selenide,Crystallization,Monomers,Nanocrystals,Nanoparticles Get e-Alerts

Specific, designed, nonperiodic arrangements of gold nanocrystals that are 5 and 10 nm in diameter can be prepared with double-stranded DNA serving as a template (see drawing; A' and B' denote oligonucleotide sequences complementary to sequences A and B). The methods described should be applicable to nanocrystals composed of various materials.

This paper is the first in a pair presented within the session: Findings from the CFS10 Multi-Hazard Test Program. The emphasis within this article is to, in brevity, describe the scope of a landmark full-scale 10-story cold-formed steel (CFS) framed building tested under multi-hazard (earthquake and fire) scenarios at the UC San Diego 6-DOF Large High-Performance Outdoor Shake Table (LHPOST6). Coined CFS10, this unique building specimen is designed beyond current code height limits, adopting advances in cold-formed steel shear wall detailing, varied construction modalities, and enriched with nonstructural components and systems. The landmark CFS10 building specimen was subjected to extreme multi-hazard (earthquake and fire) loading conditions. This paper sets the framework for presentations to be shared at the Congress, while also aiding in ongoing documentation of findings from the program.

H-1 and C-13 nuclear magnetic resonance (NMR) relaxation studies of thiophenol-capped CdS nanocrystals are presented. The transverse and longitudinal relaxation times were investigated as a function of nanocrystal radius, and the transverse relaxation time was also studied as a function of temperature. Both proton and carbon T-2 values were found to increase with nanocrystal radius, contrary to initial expectations. This effect is explained in terms of motion of the thiophenol with respect to the nanocrystalline surface. Theoretical expressions for relaxation due to anisotropic motion are developed based on both bridging and terminal bonding configurations of the thiophenol ligands, and the data are fit to these models. The data are found to be consistent with thiophenol ligands bound in a terminal fashion to a single Cd atom. The temperature dependence of the proton T-2 value is also suprising. T-2 is found to decrease with increasing temperature, and the size of this change scales with the nanocrystal radius. This is explained in terms of an extra component of relaxation due to thermally excited electrons.

Spezifische, unregelmäßige Anordnungen von Gold-Nanokristallen mit Durchmessern von 5 und 10 nm lassen sich gezielt mit Hilfe doppelsträngiger DNA als Templat herstellen (siehe Bild; A′ und B′ bezeichnen die zu den Sequenzen A bzw. B komplementären Oligonucleotidsequenzen). Die hier beschriebenen Methoden sollten sich auf Nanokristalle aus den verschiedensten Materialien anwenden lassen.

The kinetics and thermodynamics of structural transformations under pressure depend strongly on particle size due to the influence of surface free energy. By suitable design of surface structure, composition, and passivation it is possible, in principle, to prepare nanocrystals in structures inaccessible to bulk materials. However, few realizations of such extreme size-dependent behavior exist. Here, we show with molecular dynamics computer simulation that in a model of CdSe/ZnS core/shell nanocrystals the core high-pressure structure can be made metastable under ambient conditions by tuning the thickness of the shell. In nanocrystals with thick shells, we furthermore observe a wurtzite to NiAs transformation, which does not occur in the pure bulk materials. These phenomena are linked to a fundamental change in the atomistic transformation mechanism from heterogeneous nucleation at the surface to homogeneous nucleation in the crystal core.

We report the observation of size dependent structural disorder by x-ray absorption near-edge spectroscopy (XANES) in InAs and CdSe nanocrystals 17--80 \AA{} in diameter. XANES of the In and Cd ${M}_{4,5}$ edges yields features that are sharp for the bulk solid but broaden considerably as the size of the particle decreases. FEFF7 multiple-scattering simulations reproduce the size dependent broadening of the spectra if a bulklike surface reconstruction of a spherical nanocrystal model is included. This illustrates that XANES is sensitive to the structure of the entire nanocrystal including the surface.

Abstract Background: Newly discovered malignancies at a relatively younger age (<50) are of great scientific interest. Previous studies found that the incidence of these early-onset cancers showed a global increase, although the pattern varied by cancer type. However, analysis of the Hungarian data has not yet been published. Methods: The Hungarian National Cancer Registry (HNCR) is responsible for data collection of the Hungarian cancer patients. Its operation is population-based in accordance with international standards and covers the entire country. Based on the 10th Revision of International Statistical Classification of Diseases and Related Health Problems, newly discovered cancer cases were extracted from the HNCR’s database. The query focused on patients between the ages of 20 and 49 and period from 2001 to 2019. Next to absolute case numbers, age-standardized values were also analyzed (reference: European Standard Population 2013). Spearman’s correlation test was performed to identify gender- and disease-specific trends. Results: During the studied period, the incidence of early-onset cancers showed decrease among males, while it did not change among females. It should be noted that compared to the total number of newly discovered cancer cases, the proportion of early-onset cancers showed decreasing trend in both genders. Categorization by cancer type revealed that among younger age the incidence of female breast and uterine corpus cancer elevated, while cervical cancer showed a decrease - the latter trend exceeded that of the general population. The incidence of colorectal cancer did not change among females, but decreased among males. The incidence of tobacco-related lung cancer and head and neck region decreased. Conclusion: Compared to analyses enrolled global trends, the Hungarian situation of early-onset cancers seemed to be more complex. On one hand, activities in the past few years such as introduction of HPV vaccination and restrictions on smoking resulted a decrease in the number of related cancers. On the other hand, new mechanisms underlying the increasing types of cancers (e.g. breast cancer) need to be identified. Citation Format: István Kenessey, András Wéber, Mária Dobozi, István Szatmári, Petra Parrag, Péter Nagy, Magdolna Dank, . Incidence of early-onset solid cancers in Hungary in the first two decades of the 21st century based on a population-based registry [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 3569.

It is crucial to reduce natural gas methane emissions, which can potentially offset the climate benefits of replacing coal with gas. Optical gas imaging (OGI) is a widely-used method to detect methane leaks, but is labor-intensive and cannot provide leak detection results without operators' judgment. In this paper, we develop a computer vision approach to OGI-based leak detection using convolutional neural networks (CNN) trained on methane leak images to enable automatic detection. First, we collect ~1 M frames of labeled video of methane leaks from different leaking equipment for building CNN model, covering a wide range of leak sizes (5.3-2051.6 gCH4/h) and imaging distances (4.6-15.6 m). Second, we examine different background subtraction methods to extract the methane plume in the foreground. Third, we then test three CNN model variants, collectively called GasNet, to detect plumes in videos taken at other pieces of leaking equipment. We assess the ability of GasNet to perform leak detection by comparing it to a baseline method that uses optical-flow based change detection algorithm. We explore the sensitivity of results to the CNN structure, with a moderate-complexity variant performing best across distances. We find that the detection accuracy can reach as high as 99%, the overall detection accuracy can exceed 95% for a case across all leak sizes and imaging distances. Binary detection accuracy exceeds 97% for large leaks (~710 gCH4/h) imaged closely (~5-7 m). At closer imaging distances (~5-10 m), CNN-based models have greater than 94% accuracy across all leak sizes. At farthest distances (~13-16 m), performance degrades rapidly, but it can achieve above 95% accuracy to detect large leaks (>950 gCH4/h). The GasNet-based computer vision approach could be deployed in OGI surveys to allow automatic vigilance of methane leak detection with high detection accuracy in the real world.

Abstract Dendrimers and hyperbranched polymers are globular macromolecules that are characterized both by a highly branched structure, in which all bonds converge to a focal point or core, and a multiplicity of reactive chain-ends. Because of the obvious similarity of their building blocks, many assume that the properties of these two families of dendritic macromolecules are almost identical and that the terms “dendrimer” and “hyperbranched polymer” can be used interchangeably. This assumption is incorrect because only regular dendrimers have a precise end-group multiplicity and functionality and exhibit properties that are totally unlike those of all other families of macromolecules. For example, regular dendrimers display a maximum in the relationship between their intrinsic the applications that are contemplated for the dendritic polymers. Using living systems as a model, one must anticipate that the regular placement of reactive groups at a precise location, as opposed to throughout a structure, has great importance in terms of ultimate performance when surface and interfacial properties are involved. Therefore, just like Langmuir-Blodgett films, dendrimers belong to a special class of well-defined molecular architectures where exact structure and ultimate performance are intimately related. It is likely that regular dendrimers will continue to draw much attention in specialized applications that take advantage of their precise architecture: drug delivery, catalysis, nanoreactors, molecular devices, etc. In contrast, hyperbranched polymers will join other interesting functional polymers in applications that involve commodity materials: from coatings and adhesives to lubricants, compatibilizers, and carriers. Today, the frontiers in the chemistry of dendritic polymer are in the search for rapid methods of synthesis involving, for example, vinyl polymerizations [46, 50], the preparation of “engineered” dendritic structures, and the discovery of new properties and applications [1, 47].