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What Can Be Improved in GC-MS—When Multi Benefits Can Be Transformed into a GC-MS Revolution

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International Journal of Analytical Mass Spectrometry and Chromatography 2013年第1期1卷 31-47页

作者： Aviv Amirav Alexander B. Fialkov tal alon School of Chemistry Tel Aviv University Tel Aviv Israel School of Chemistry Tel Aviv University Tel Aviv Israel Aviv Analytical Ltd Tel Aviv Israel School of Chemistry Tel Aviv University Tel Aviv Israel Aviv Analytical Ltd Tel Aviv Israel Afeka College Tel Aviv Israel

Gas chromatography mass spectrometry (GC-MS) is a widely used central analytical technology. Commercially available GC-MS systems use different types of mass analyzers such as Quadrupole, Ion Trap and/or Time of Flight, but practically all systems utilize the same Nier type electron ionization (EI) ion source and the same standard GC-MS transferline interface. Consequently, the various GC-MS vendors characterize their systems by a short list of specifications that relate to improvements in the technology of GC or of MS and not of the interfacing technology and ion source. This article presents a list of 62 ways in which the performance of GC-MS as a whole can be improved by an innovative interface and ion source. Such an interface can possibly lead to a GC-MS revolution in a way that is similar to that whichis brought to Liquid Chromatography Mass Spectrometry (LC-MS) by the Electrospray ionization interface and ion source and not by improvements to the technology of LC or MS. These 62 possible GC-MS improvements (grouped into eight main categories) are not merely theoretical as they are provided by the Cold-EI GC-MS interface, which is based on the ionization of vibrationally cold sample molecules in a Supersonic Molecular Beam (SMB) within a fly-through ion source. An explanation and discussion is provided for each of these possible improvements.

关键词： Gas Chromatography Mass Spectrometry (GC-MS) Supersonic Molecular Beams Cold EI Instrument Development

Eco-ableism and access circularity in natural building

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Frontiers of Architectural Research 2024年第2期13卷 235-248页

作者： Grace Schleck Lola Ben-alon Barnard College Department of Architecture New YorkUSA Columbia University Graduate School of Architecture Planningand Preservation(GSAPP)New YorkUSA

The climate crisis disproportionately impacts disabled people. Yet climate-related advocacy, planning, and policymaking often neglect to thoughtfully include disabled people. Responding to this gap, disabled and neurodivergent environmental activists coined the term eco-ableism to describe discrimination and silencing toward disabled and neurodivergent people (i.e., ableism) arising in environmental spaces (i.e., eco-ableism). Relatedly, building operations and construction practices contribute a significant percentage of global, energy-related CO_(2) emissions annually, which calls into question the relationships between the impending climate crisis, disability justice, and architecture. Climate-specific, natural building materials and methods present a potential pathway toward a more sustainable built future: low-carbon, locally sourced, minimally processed, and nontoxic materials. Despite a critical overlap, there is little published research on material access in the production phase and human access in the occupation phase of natural buildings. Applying eco-ableism and material circularity in an architectural framework, this research aims to investigate the gaps and possibilities of access, natural material applications, and resulting US natural buildings informed by scholarship in critical disability studies and semi-structured interviews with natural building professionals.

关键词： Eco-ableism Critical disability studies Climate crisis and architecture Naturalmaterialsand methods

Computational Study of Interstitial Hydrogen Atoms in Nano-Diamond Grains Embedded in an Amorphous Carbon Shell

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Communications in Computational Physics 2011年第4期9卷 843-858页

作者： Amihai Silverman alon Hoffman Joan Adler Taub Computer Center Technion-IITHaifa 32000Israel Schulich Faculty of Chemistry Technion-IITHaifa 32000Israel Department of Physics Technion-IITHaifa 32000Israel

The properties of hydrogen atoms in a nano-diamond grain surrounded by an amorphous carbon shell are studied with Tight Binding computer *** samples model nano-diamond grains,of a few nanometers in size,that nucleate within an amorphous carbon matrix,as observed in deposition from a hydrocarbon rich *** calculations show that the average hydrogen interstitial formation energy in the amorphous region is lower than in the nano-diamond core,therefore hydrogen interstitial sites in the in the amorphous region are more stable than in the nano-diamond *** formation energy difference is the driving force for the diffusion of hydrogen atoms from nano-diamond grains into amorphous carbon *** energy well was observed on the amorphous side of the nano-diamond amorphous carbon interface:hydrogen atoms are expected to be trapped *** scenario agrees with experimental results which show that hydrogen retention of diamond films increases with decreasing grain size,and suggest that hydrogen is bonded and trapped in nano-diamond grain boundaries and on internal grain surfaces.

关键词： Nano-diamond amorphous-carbon DOS NEXAFS molecular-dynamics tightbinding

Numerical estimation of choice of the regularization parameter for NMR T2 inversion

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Petroleum Science 2016年第2期13卷 237-246页

作者： You-Long Zou Ran-Hong Xie alon Arad State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum Beijing 102249China Shell International Exploration and Production Inc. Houston 77079 TX USA

Nuclear Magnetic inversion is the basis of NMR Resonance （NMR） T2 logging interpretation. The regularization parameter selection of the penalty term directly influences the NMR T2 inversion result. We implemented both norm smoothing and curvature smoothing methods for NMR T2 inversion, and compared the inversion results with respect to the optimal regular- ization parameters （（Xopt） which were selected by the dis- crepancy principle （DP）, generalized cross-validation （GCV）, S-curve, L-curve, and the slope of L-curve methods, respectively. The numerical results indicate that the DP method can lead to an oscillating or oversmoothed solution which is caused by an inaccurately estimated noise level. The （Xopt selected by the L-curve method is occa- sionally small or large which causes an undersmoothed or oversmoothed T2 distribution. The inversion results from GCV, S-curve and the slope of L-curve methods show satisfying inversion results. The slope of the L-curve method with less computation is more suitable for NMR T2 inversion. The inverted T2 distribution from norm smoothing is better than that from curvature smoothing when the noise level is high.

关键词： NMR T2 inversion Tikhonov regularizationVariable substitution Levenberg-Marquardt method Regularization parameter selection

Risk factors for an atherothrombotic event in patients with diabetic macular edema treated with intravitreal injections of bevacizumab

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International Journal of Ophthalmology(English edition) 2020年第9期13卷 1411-1416页

作者： alon Tiosano Aviel Hadad Noam Yanculovic Department of Ophthalmology Soroka University Medical CenterBen-Gurion University of the NegevBeer Sheva 84101Israel

AIM:To identify risk factors for an atherothrombotic event(ATE)among patients who were treated for diabetic macular edema(DME)with intravitreal bevacizumab ***:This retrospective study enrolled all consecutive patients with DME who were treated by intravitreal bevacizumab from 2009 through 2016 in a single *** were divided into one group treated by bevacizumab and subsequently had an ATE and a second group also treated by bevacizumab and did not have an ***:A total of 455 patients with DME were ***-two of the patients had an ATE.A multivariate model adjusted for age,gender,smoking,body mass index,hemoglobin A1c(HbA1c),duration of diabetes,creatinine,and blood pressure revealed an increased risk for ATE in the patients with diabetic duration of more than 13 y,a systolic blood pressure over 153.5 mm Hg at first treatment,or having been treated by more than 4 intravitreal bevacizumab ***,patients that had an ATE within 3 mo from the last intravitreal treatment underwent more bevacizumab injections(5.2±3.4 vs 3.07±1.86;P153.5 mm Hg,a history of diabetic mellitus for more than 13 y,and treatment with more than 4 intravitreal bevacizumab *** factors need to be borne in mind when bevacizumab is being considered in the management of patients with DME.

关键词： atherothrombotic event bevacizumab diabetic macular edema

Synthetic aperture-based on-chip microscopy

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Light(Science & Applications) 2015年第1期4卷 438-446页

作者： Wei Luo alon Greenbaum Yibo Zhang Aydogan Ozcan Electrical Engineering Department University of CaliforniaLos AngelesCA 90095USA Bioengineering Department University of CaliforniaLos AngelesCA 90095USA California NanoSystems Institute(CNSI) University of CaliforniaLos AngelesCA 90095USA Department of Surgery David Geffen School of MedicineUniversity of CaliforniaLos AngelesCA 90095USA

Wide field-of-view(FOV)and high-resolution imaging requires microscopy modalities to have large space-bandwidth *** on-chip microscopy decouples resolution from FOV and can achieve a space-bandwidth product greater than one billion under unit magnification using state-of-the-art opto-electronic sensor chips and pixel super-resolution ***,using vertical illumination,the effective numerical aperture(NA)that can be achieved with an on-chip microscope is limited by a poor signal-to-noise ratio(SNR)at high spatial frequencies and imaging artifacts that arise as a result of the relatively narrow acceptance angles of the sensor’s ***,we report,for the first time,a synthetic aperture-based on-chip microscope in which the illumination angle is scanned across the surface of a dome to increase the effective NA of the reconstructed lensfree image to 1.4,achieving e.g.,,250-nm resolution at 700-nm wavelength under unit *** synthetic aperture approach not only represents the largest NA achieved to date using an on-chip microscope but also enables color imaging of connected tissue samples,such as pathology slides,by achieving robust phase recovery without the need for multi-height scanning or any prior information about the *** validate the effectiveness of this synthetic aperture-based,partially coherent,holographic on-chip microscope,we have successfully imaged color-stained cancer tissue slides as well as unstained Papanicolaou smears across a very large FOV of 20.5 mm^(2).This compact on-chip microscope based on a synthetic aperture approach could be useful for various applications in medicine,physical sciences and engineering that demand high-resolution wide-field imaging.

关键词： computational imaging lensfree microscopy on-chip microscopy synthetic aperture

Research progress on solid-fueled Scramjet

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Chinese Journal of Aeronautics 2022年第1期35卷 398-415页

作者： Xiang ZHAO Zhixun XIA Likun MA Chaolong LI Chuanbo FANG Benveniste NATAN alon GANY Department of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China Qinghe Building Ding-3 Beijing 100085China Faculty of Aerospace Engineering Technion-Israel Institute of TechnologyHaifa 32000Israel

The solid-fueled Scramjet is an interesting option for supersonic combustion *** shows significant advantages such as simple fuel supply and compactness,avoiding the complex system of tanks and pipelines that encountered in liquid-fueled *** solid-fueled Scramjet could be the simplest air-breathing engine for the hypersonic flight *** paper presents a comprehensive and systematic review of the research progress on solid-fueled Scramjet in various institutes and *** summarizes a progress overview of three types of the solid-fueled Scramjet,which covers a wealth of landmark numerical and experimental *** on this,several relevant key technologies are *** inherent scientific issues are refined,such as the mixing mechanism of multi-phase flow and supersonic airflow,ignition and combustion mechanism of the condensed phase in a supersonic airflow,and coupling mechanism of gas and solid phase in a supersonic ***,the historical development trend is clarified,and some recommendations are provided for future solid-fueled Scramjet.

关键词： Combustor performance Flame stabilization Self-ignition Solid-fueled Scramjet Supersonic combustion ramjet

The Wingate anaerobic test cannot be used for the evaluation of growth hormone secretion in children with short stature

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Journal of Sport and Health Science 2017年第4期6卷 443-446页

作者： Nitzan Dror Liat Oren Michal Pantanowitz alon Eliakim Dan Nemet Child Health and Sports Center Pediatric Department Meir Medical Center Sackler School of Medicine Tel Aviv University Kfar-Saba 44281 Israel

Purpose: To assess the growth hormone(GH) response to the Wingate anaerobic test(WAn T) among children with short stature and suspected GH deficiency. We hypothesized that the GH response to the WAn T would be similar to the GH response to a commonly used pharmacologic provocation ***: Ten children(6 males and 4 females, age range 9.0–14.9 years) participated in the study. Each participant performed 2 tests: a standard all-out WAn T, cycling for 30 s against constant resistance, and a standardized pharmacologic test(clonidine or glucagon). Blood samples for GH were collected before and 10, 30, 45, and 60 min after the beginning of exercise. In addition, we collected pre-and post-exercise blood lactate ***: There was a significant increase in GH levels after the WAn T, yet in 9 of 10 participants, this increase was below the threshold for GH sufficiency. Peak GH after the WAn T was significantly lower compared to the pharmacologic GH provocation tests(with 9 of 10 demonstrating GH-sufficient response).Conclusion: The traditional WAn T cannot be used as a GH provocation test. Further research is needed to develop anaerobic exercise protocols sufficient to promote GH secretion.

关键词： Anaerobic Exercise Growth hormone Lactate Provocation test Short stature

Chemical, carbon and sulfur isotopic compositions constrain the origin of Upper Carboniferous-Lower Triassic gases in eastern Sichuan Basin, SW China

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Science China Earth Sciences 2024年第10期67卷 3169-3185页

作者： Chunfang CAI Ilya KUTUZOV Wenhua MEI Daowei WANG Bing LUO Shipeng HUANG Bing HE alon AMRANI China University of Petroleum National Key Lab Petroleum Resource&EngineeringBeijing 102249China State Key Laboratory of Lithospheric and Environmental Coevolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Institute of Earth Sciences The Hebrew UniversityJerusalem 91904Israel College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Yulin University Yulin 719000China Research Institute of Exploration and Development Southwest Oil&Gas Field CompanyPetroChinaChengdu 610051China PetroChina Research Institute of Petroleum Exploration and DevelopmentBeijing 100083China

Methane dominated gas is one of the cleanest energy resources;however, there is no direct method to determine its source rock. Natural gases produced from the eastern Sichuan Basin together with seismic data were studied for their sources and secondary alteration by thermochemical sulfate reduction(TSR). Our results demonstrate that Upper Permian to Lower Triassic(P_(3)ch-T_(1)f) gases in the surrounding of the Kaijiang-Liangping area show volatile organic sulfur compounds(VOSCs) δ^(34)S values close to those of the associated H_(2)S, and may have been altered by methane-dominated TSR, resulting in positive shift in methane δ^(13)C_(1)values with increasing TSR extents. Other(or group 2) gases produced from the P_(3)ch-T_(1)f reservoirs from the southern area and the Upper Carboniferous to Middle Permian(C_(2)h-P_(2)q) from the eastern Sichuan Basin are not significantly changed by TSR, show similar δ^(34)S values between the kerogens and some VOSCs, and may have been derived from the Lower Silurian and Middle Permian source rocks. This study demonstrates a case for the first time showing the δ^(34)S values of VOSCs can be used as a tool for direct correlation between non-TSR altered gas and source rocks. Methane-dominated gas pools can be found using gas and source rock geochemistry combined with seismic data.

关键词： Sulfur isotopes Volatile organic sulfur compounds Thermochemical sulfate reduction Sichuan Basin Gas-source rock correlation