The CMS Phase I Pixel Upgrade and Search for ttbar Resonances in Boosted Semileptonic Final States

The pixel detector is an integral part of the CMS silicon tracker, designed to measure the position and momentum of charged particles produced in high-energy collisions at the Large Hadron Collider (LHC). The phase I upgrade of the CMS forward pixel detector has replaced the previous forward pixel detector in early 2017. In this thesis, I will discuss the testing and qualification procedures for the modules and half cylinders of the CMS Phase I FPIX detector. This thesis also presents a model-independent search for the production of heavy resonances decaying into top-antitop quark pairs using data recorded by the CMS detector in 2018 (integrated luminosity of 58.8 /fb). The analysis focuses on the semi-leptonic decaying channel of the top-antitop quark pair. I focus on events that contain one muon, large missing transverse momentum and at least two high transverse momentum jets, and use special event reconstruction techniques that are optimized for top quarks with high Lorentz boosts

Subarray-Based Near-Field Channel Estimation for Extremely Large Antenna Array Systems

The deployment of extremely large antenna arrays (ELAAs) at transceivers is a promising technology for next-generation wireless communication. With the increase in the number of antennas at the receiver and the adoption of high-frequency communication, the transmitters and/or scatterers may be located within the near-  eld region of the receiver, constituting near- eld communication. As a result, traditional far- eld techniques may become inapplicable, and the channel's near- eld nature demands innovative solutions. Furthermore, ELAA systems have substantial power needs, particularly when fully digital architectures are used. To address this challenge, hybrid architectures are considered as a viable alternative. However, during each channel use, the number of observations is limited at hybrid receivers. Therefore, near- eld channel estimation in ELAA systems requires increased overhead and computational complexity. This thesis investigates near- eld localization and channel estimation for ELAA systems. A hybrid receiver equipped with a uniform linear array (ULA) is considered in a single-input multiple-output (SIMO) con guration. We propose a subarraybased solution that reduces the antenna aperture to e ectively shrink the near- eld range. By doing so, the transmitters and/or scatterers are positioned within the far  eld of the subarray, thereby enabling the application of far- eld-based techniques. Firstly, we estimate subarray directions of arrival (DoAs) and times of arrival (ToAs) by using atomic norm minimization (ANM) and root multiple signal classi cation (root-MUSIC) techniques. Secondly, the transmitter/scatterers' locations are jointly estimated from the multiple subarray DoAs and the corresponding subarray ToAs after association. Then, to improve the channel estimation performance, the estimated locations are re ned using grid search or gradient descent. Finally, the near- eld channel is reconstructed based on the re ned transmitter/scatterers' locations. Subsequently, we also propose a generalized nested sampling (GNS)-based alternative to reduce the computational complexity. Simulation results demonstrate that the proposed solutions can achieve high-accuracy localization and channel estimation. Besides, the complexity of the proposed estimator can be alleviated with the proposed GNS-based method, as only a selected number of receiver antennas need to be activated.</p

Convergent Route to β‑Amino Acids and to β‑Heteroarylethylamines: An Unexpected Vinylation Reaction

Various protected β2-amino acids can be prepared by radical addition of β-phthalimido-α-xanthyl propionic acid, both as the free acid or as the ethyl ester. Successive radical additions provide access to more complex structures. In the case of the free acid, addition to certain heteroaromatics leads directly to β-heteroarylethylamines through spontaneous decarboxylation of the intermediate adduct. Forcing the decarboxylation in some cases generated a vinyl group by decarboxylative elimination of the phthalimido group

Bounds on Treatment Effects in the Presence of Sample Selection and Noncompliance: The Wage Effects of Job Corps

<div><p>Randomized and natural experiments are commonly used in economics and other social science fields to estimate the effect of programs and interventions. Even when employing experimental data, assessing the impact of a treatment is often complicated by the presence of sample selection (outcomes are only observed for a selected group) and noncompliance (some treatment group individuals do not receive the treatment while some control individuals do). We address both of these identification problems simultaneously and derive nonparametric bounds for average treatment effects within a principal stratification framework. We employ these bounds to empirically assess the wage effects of Job Corps (JC), the most comprehensive and largest federally funded job training program for disadvantaged youth in the United States. Our results strongly suggest positive average effects of JC on wages for individuals who comply with their treatment assignment and would be employed whether or not they enrolled in JC (the “always-employed compliers”). Under relatively weak monotonicity and mean dominance assumptions, we find that this average effect is between 5.7% and 13.9% 4 years after randomization, and between 7.7% and 17.5% for non-Hispanics. Our results are consistent with larger effects of JC on wages than those found without adjusting for noncompliance.</p></div

An Ionic-Radical Approach to Vicinally Functionalized Cyclopentanones and Cyclohexanones

A versatile strategy to access vicinally functionalized cyclopentanones and cyclohexanones is described. It takes advantage of new reagents, α-xanthyl enones, which can be prepared from the reaction of xanthate salts with the corresponding epoxyketones under mild conditions. β-Functionalization of these compounds can be performed by conjugate additions without affecting the xanthate moiety. This significantly expands the pool of xanthate substrates, allowing the synthesis of open chain and fused bicyclic building blocks useful in the synthesis of natural products

Additional file 1: Table S1. of Identification and functional analysis of the L-ascorbate-specific enzyme II complex of the phosphotransferase system in Streptococcus mutans

Primers used in this study. (DOC 62 kb

Tannin-Derived Ordered Mesoporous Carbon Cathode for Zn-Ion Hybrid Supercapacitor with Remarkable Energy Density

Zn-ion hybrid supercapacitors (ZHSCs) have been considered as a promising candidate for energy storage systems because of the merits they inherited from both supercapacitors and rechargeable batteries. Herein, we show the eco-friendly modified solvent evaporation-induced self-assembly (EISA) synthesis of newly engineered plant polyphenol tannin-derived ordered mesoporous carbons (TOMCs) and employ them as cathode material for high-performance ZHSCs to promote the diffusion dynamics of Zn2+ ions for the first time. The optimized TOMC-700 possesses a high Brunauer–Emmett–Teller (BET) surface area of 967 m2 g–1, narrow mesopores centered at ∼3.5 nm, and rich heteroatoms. Profiting from the synergy of enhanced kinetics and electroactivity, the aqueous TOMC-700-based ZHSC exhibits intriguing Zn-storage capabilities, including a superior energy density of 148.9 Wh kg–1 at 180 W kg–1 in a broad potential range of 0–1.8 V and long-term cycling stability. Moreover, the quasi-solid TOMC-700-based ZHSC also delivers an outstanding energy density of 121.3 Wh kg–1 at 180 W kg–1. These results highlight the facile fabrication of a natural carbohydrate-derived ordered mesoporous carbon as cathode material, notably boosting the development of Zn-based hybrid energy storage systems

F10 iteration curve.

F10 iteration curve.</p

Computational time of each algorithm—Part I.

Computational time of each algorithm—Part I.</p

Main parameters of the 7 algorithms.

Main parameters of the 7 algorithms.</p