Synthesis of dihydro-β-carbolines by tandem C-H activation and aza-Michael reaction in the presence of Rh(II)/squaramide catalysis: Investigation of the mechanism via computational methods

N-heterocycles are the major component of various bioactive natural products, pharmaceuticals, and their precursors. In particularly, β-carbolines are examples of substituted indole and its derivatives that serve as the basic structures of diverse, therapeutically important molecules with broad pharmacological properties. Rajasekar and Anbarasan have suggested a novel one-pot synthesis for dihydro-β-carbolines involving more than one catalytic system: a rhodium acetate dimer for C-H insertion on the indole and a basic organo-catalyst for the subsequent aza-Michael addition. The product can be obtained enantioselectively by using a chiral squaramide as the organo-catalyst. Since the mechanism of this reaction, including the rate determining step, has not been explored by either experimental or computational methods, the purpose of this study is to model the catalytic cycle and delineate the energetics of the reaction pathway. We have determined the structure of all intermediates and several transition states and calculated relative activation barriers using density functional theory (DFT) methods as implemented in the Gaussian suite of programs. We find that the nitrogen extrusion step has the highest activation barrier of those determined so far

Development of a Standard Test Method for Characterization of Asphalt Materials and Aging-Related Degradation using an Extensional Rheometer

An extensional deformation test method using a Sentmanat Extensional Rheometer (SER) fixture inside a Dynamic Shear Rheometer (DSR) is developed in this study to investigate the degradation of the polymer due to aging and to investigate the effect of modifier type. A relationship between different percentages of modifier and ductility of the modified binder is also investigated. The sample geometrics used in this study are 1 mm x 0.72 mm and 3 mm x 0.72 mm. A total of one hundred and sixty-two samples were tested. Three modifiers Styrene-Butadiene-Styrene (SBS), Polyphosphoric Acid (PPA) and latex were used. One PG 76-22, one PG 64-22 and one polymer-modified asphalt emulsion (PAME) were used. First peak elongation force, (F1) is the binders’ stiffness and Second peak elongation force, (F2) is the polymer characteristics. F2 is more visible comparatively at the higher temperature. In most cases, F2 reduces after Rolling Thin Film Oven (RTFO) and Pressure Aging Vessel (PAV) aging. To normalize the stiffness effect of F1 on F2, in this study F2/F1 was used to analyze aging susceptibility of modifiers. All the testing temperatures used in this study exhibited a reduction in F2/F1 due to RTFO aging and further reduction due to PAV aging. Therefore, through this study, it is recommended that this parameter can be used to determine aging susceptibility of polymer in a polymer-modified asphalt binder. F2 is only obtained from the SBS and latex modified binders and emulsions. Addition of PPA did not show any F2, making SBS the most effective modifier among SBS, PPA and latex. F2 has a linear correlation with the percent of the polymer in the PMAE, SBS modified PG 64-22, SBS and PPA modified PG 64-22 and latex modified PG 64-22 with R2 values equal to 0.9934, 0.9323, 0.9893 and 0.9535 respectively, indicating extensional deformation test with SER very promising. Ductility analyses using final angular strain values indicate that modifiers increase ductility significantly while aging reduces ductility. Additional research is required for testing ultra-violet (UV) aged sample, and a DSR-based SER test specification will be developed subsequentl

Effect of additives on surface free energy characteristics of aggregates and binders in hot mix asphalt.

U.S. spends approximately $20 billion/year on asphalt pavements with disproportionately high maintenance costs of$9.3 billion/year. Better performance of asphalt pavements is crucial to reducing these maintenance costs. During the past two decades significant advances have been made in understanding the behavior of hot mix asphalt (HMA) and in improving the design of asphalt pavements. In spite of these efforts, moisture-induced damage (also called stripping) is still one of the most common (75% of total road damage in one of the states surveyed) and complex problems. In this study, a mechanism-based approach based on the surface free energy (SFE) characteristics of asphalt binders and aggregates was used to elucidate on the asphalt-aggregate interactions for moisture-induced damage mechanisms. Researchers at the Texas Transportation Institute (TTI) have been using the SFE method to evaluate different asphalt binders and aggregates for moisture-induced damages. In this study, asphalt binders and aggregates were evaluated for moisture-induced damage after being modified with four different types of additives, namely liquid amines, styrene-butadiene rubber (SBR) emulsion, commercial wax and synthetic zeolite. Based on their effects relative to control samples without additives, the moisture-induced damage mechanisms are explained. A chemical model was developed which can explain that basic chemical compounds such as amines in the form of anti-strip additives reduce the acid component of SFE and increase the base component of SFE of an asphalt binder and favor the adhesion between acidic asphalt binders and acidic aggregates. The model can be used to explain that the beneficial effect of anti-strip additives in acid-base characteristics of asphalt binders is severely reduced by Rolling Thin Film Oven (RTFO) aging and Pressure Aging Vessel (PAV) aging. The analyses also provides an explanation that the acid SFE of acidic aggregate such as sandstone is significantly reduced and the base SFE is increased by SBR coating and thus, favors the adhesion between an acidic asphalt binder and an acidic aggregate. Besides the acid-base characteristics, the model can explain wettability (spreading coefficient), adhesion (free energy of adhesion) and moisture susceptibility (spontaneous change in free energy under water). One warm mix asphalt (WMA) additive, SasobitRTM (a commercial wax) was found to increase the wettability and decrease the adhesion of asphalt binders significantly. No significant effect of the second WMA additive, Aspha-MinRTM (a synthetic zeolite) was observed. Therefore, the chemical model proposed in this study has a set of parameters, namely Lewis acid surface parameter, Lewis base surface parameter, wettability, adhesion and moisture susceptibility that were found to be important in explaining the asphalt-aggregate interaction mechanisms. In this dissertation, the effects of amine anti-strip, RTFO and PAV-aging, and SBR polymer coating are presented in Chapters 2, 3 and 4, respectively. Effects of Sasobit RTM and Aspha-MinRTM on the binder rheology and the SFE characteristics are presented in Chapters 5 and 6, respectively. The results of this study can be used as a tool for cataloging of materials to predict moisture-induced damage in asphalt pavement

Towards building a practical face recognition system

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (p. 56-57).by Wasiuddin A.S.M. Wahid.M.Eng

Literature as a Form of Resistance Against British Colonial Rule in India

This thesis concentrates on literature during India\u27s battle for independence from the British Empire. These publications look at the outcomes of Europe\u27s intent to colonize and its impact on the marginalized, colonial subjects down to the personal level. Delving into the tragic reality of colonialism and investigating its impact as portrayed in the novels selected, this thesis argues that the selected texts operate as resistance literature subverting the colonial discourse in retrieving South Asian culture and history. This project explores specific forms of resistance within the tropes of memory, history, and gender to pose a larger question of decolonial futures in the postcolonial aftermath. The explorations of Ahmed Ali\u27s Twilight in Delhi, Rabindranath Tagore\u27s The Home and the World, and R.K. Narayan\u27s Waiting for the Mahatma all represent multiple ways of studying the independence movement in their resistance frame. Analyzing these works through a postcolonial perspective unveils underrepresented voices and the intricacies of the Independence landscape. Ahmed Ali incorporates nostalgia as an argument for abolition and articulates Muslim identity in India\u27s rapidly transforming environment. Tagore writes from his real experiences, recounting the confusion and disarray that plagued the Independence movement as disputes erupted on how to fight for India\u27s sovereignty. R.K. Narayan embraces the ‘Quit India\u27 protest and Gandhi\u27s pacifist ideals while worrying about the future after the Mahatma\u27s death. These writers decolonize readers\u27 minds, and campaign for India\u27s independence against the Empire Such literature gives the colonized a voice as they actively resist the British colonization in every aspect of existence

Tinjauan siyasah maliyah terhadap kedudukan perda nomor 5 tahun 2020 tentang perumda air minum Tirta Kahuripan Kabupaten bogor dalam meningkatkan pendapatan asli daerah melalui perumda air minum Tirta Kahuripan Kabupaten Bogor

Perumda Air Minum Tirta Kahuripan Kabupaten Bogor merupakan salah satu item Badan Usaha Milik Daerah (BUMD) yang dikelola secara mandiri oleh daerah guna berkontribusi secara langsung terhadap Pendapatan Asli Daerah khususnya di Kabupaten Bogor. Di Kab. Bogor sendiri terdapat Badan Usaha Milik Daerah (BUMD) yang menjadi salah satu faktor penunjang terhadap Pendapatan Asli Daerah (PAD) setelah pajak yakni Perumda Air Minun Tirta Kahuripan Kab. Bogor, lalu bagai mana upaya dan kontribusi yang dilakukannya dalam meningkatkan Pendaparan Asli Daerah (PAD) Kab. Bogor. Tujuan Penelitian ini untuk mengetahui: 1) Upaya yang dilakukan Perumda Air Minum Tirta Kahuripan Kab. Bogor dalam meningkatkan Pendapatan Asli Daerah (PAD) Kab. Bogor 2) Kontribusi yang dilakukan Perumda Air Minum Tirta Kahuripan Kab. Bogor dalam meningkatkan Pendapatan Asli Daerah (PAD) Kab. Bogor 3) Perpektif Siyasah Maliyah terhadap Upaya dan Kontribusi yang dilakukan Perumda Air Minum Tirta Kahuripan Kab. Bogor dalam meningkatkan Pendapatan Asli Daerah (PAD) Kab. Bogor . Teori yang digunakan dalam penelitian ini adalah teori pemerintahan yang baik (good governance) bertujuan untuk menciptakan nilai bagi pemangku kepentingan melalui praktik yang transparan, akuntabel, dan bertanggung jawab. Yang kedua menggunakan teori negara kesejahteraan (welfare state) bagaimana negara menjamin keadilan sosial (social justice) bagi seluruh masyarakat Dan dua teori siyasah maliyah yakni teori tanggung jawab negara dan sumber pendapatan negara yang menekankan konsep aturan kemaslahatan rakyat dalam ekonomi dan sumber daya alam negara. Metode penelitian ini menggunakan, metode penelitian kualitatif dengan jenis metode kualitatif yang digunakan yakni metode kualitatif deskriptif. Pendekatan yang digunakan adalah pendekatan yuridis empiris. Sumber data berasal dari Data Primer (wawancara), Data Sekunder (Peraturan Daerah (Perda) Kab. Bogor Nomor 5 Tahun 2020 tentang Perumda Air Minum Tirta Kahuripan Kab. Bogor). Teknik pengumpulan data diambil secara observasi, wawancara, dokumentasi, dan studi kepustakaan. Analisis data yang digunakan adalah pengumpulan data, reduksi data, dan penarikan kesimpulan. Hasil penelitian ini dapat ditarik kesimpulan bahwa: 1). Upaya yang dilakukan Perumda Air Minum Tirta Kahuripan Kab. Bogor dalam meningkatkan Pendapatan Asli Daerah (PAD) Kab. Bogor diantaranya : a. Meningkatkan pendapatan penjualan air b. Meningkatkan cakupan pelayanan c. Efisiensi belanja langsung dan tidak langsung d. 2) Kontribusi yang dihasilkan Perumda Air Minum Tirta Kahuripan Kab. Bogor dalam meningkatkan Pendapatan Asli Daerah (PAD) Kab. Bogor mampu menyumbang deviden terhadap pemerintah daerah yang dalam kurun waktu 5 tahun antara tahun 2019-2023 terus mengalami peningkatan laba bersih dengan rata-rata 2% setiap tahunnya. Dalam perspektif siyasah maliyah berkenaan dengan upaya dan kontribusi Perumda Air Minum Tirta Kahuripan Kabupaten Bogor telah sesuai dengan teori siyasah maliyah yakni terciptanya jaminan sosial (ad-dhaman al-ijtima’i), keseimbangan sosial (at-tawazun al-ijtima’i), intervensi negara (at-tadkhkhul ad-daulah) dan teori sumber pendapatan negara menggunakan istilah Fay

On Reducing Underutilization of Security Standards by Deriving Actionable Rules: An Application to IoT

Even though there exist a number of security guidelines and recommendations from various worldwide standardization authorities (e.g., NIST, ISO, ENISA), it is evident from many of the recent attacks that these standards are not strictly followed in the implementation of real-world products. Furthermore, most security applications (e.g., monitoring and auditing) do not consider those standards as the basis of their security check. Therefore, regardless of continuous efforts in publishing security standards, they are still under-utilized in practice. Such under-utilization might be caused by the fact that existing security standards are intended more for high-level recommendations than for being readily adopted to automated security applications on the system-level data. Bridging this gap between high-level recommendations and low-level system implementations becomes extremely difficult, as a fully automated solution might suffer from high inaccuracy, whereas a fully manual approach might require tedious efforts. Therefore, in this thesis, we aim for a more practical solution by proposing a partially automated approach, where it automates the tedious tasks (e.g., summarizing long standard documents, and extracting device specifications) and relies on manual efforts from security experts to avoid mistakes in finalizing security rules. We apply our solution to IoT by implementing it with IoT-specific standards (NISTIR 8228) and smart home networks. We further demonstrate the actionability of our derived rules in three major applications: security auditing, Intrusion Detection systems (IDS), and secure application development

Laboratory evaluation on the characteristics and pollutant emissions of nanoclay and chemical warm mix asphalt modified binders

This study was conducted to investigate the performance characteristics of nanoclay- and chemical warm-mix asphalt (WMA) additive-modified asphalt binders in terms of their chemical, morphology, rheological and surface energy properties in comparison to conventional asphalt binder. Both the nanoclay modified asphalt binder (NCMB B) and the chemical WMA additive modified asphalt binder (CWAA) were artificially aged under short-term and long-term aging conditions prior to evaluation. The chemical and morphological properties were measured with Fourier Transform Infrared (FTIR) spectroscopy and Field-Emission Scanning Electron Microscopy (FE-SEM) respectively. Rheological eval-uations were conducted to determine binder’s behavior under short-term aging in terms of frequency sweep, temperature sweep, and creep recovery tests by utilizing the dynamic shear rheometer (DSR) machine. Emission test was also conducted on the unmodified and modified WMA mixtures to estimate the gaseous pollutants emitted during their manufacture. FTIR spectroscopy results showed that the addition of WMA modifiers into asphalt binder could delay and weaken the oxidation reaction of the binder which in turn improved the aging process. However, the physical structure did not seem to show any changes after undergoing long term aging. The use of NCMB B 4% (by weight of asphalt binder) seemed to produce better resistance towards rutting when compared to CWAA 1%, 2% and 3% for unaged, and short- and long-term aging test conditions. The modified binders exhibit significantly higher surface energy and hence produced good adhesion between aggregates, which imply increased resistance toward moisture-induced damage. This study also revealed that the manufacture of WMA mixtures reduced up to 50% of the pollutants emitted during mixing in laboratory

Characterization of Asphalt Binders Exposed to Extreme Temperatures through Simple and Effective Test Methods

DTRT13-G-UTC36In the Arkansas State University (ASU) study, Superpave and Multiple Stress Creep and Recovery (MSCR) tests were performed to evaluate viscoelastic properties of selected asphalt binders approved in Arkansas and Texas. A total of 65 binder samples were tested in the laboratory. Of these, eight were unmodified binders, 24 were polymer-modified binders (PMBs), 27 were warm mix asphalt (WMA)-additive modified, and 6 were reclaimed asphalt pavement (RAP) modified binders. The non-recoverable compliance and MSCR percent recovery data of the tested binders were analyzed for grading and establishing the MSCR percent recovery criteria for local service temperature and traffic conditions. The developed guidelines are expected to be helpful for transportation agencies in Arkansas and Texas to adopt the MSCR test method in their quality control process. In the University of Oklahoma (OU) study, the polymer-modified binders were found to meet the Superpave\uae specifications and exhibited satisfactory rutting and fatigue resistance. The high- and low-temperature performance grade (PG) grades of the RAP binder blends were observed to increase with an increase in the RAP binder content. From the MSCR test results, the minimum %Recovery requirement based on the Jnr criteria suggested in American Association of State Highway and Transportation Officials (AASHTO) TP 70 was found to be appropriate for differentiating polymer-modified binders from non-polymer modified binders. Also, the addition of a higher stress level, such as 10 kPa to the MSCR test method, was found to help understand the nonlinear viscoelastic behavior of the polymer-modified binders. Furthermore, the Jnr value decreased and MSCR grades increased with an increase in the amount of RAP binder, which indicated an improved resistance to rutting for the RAP binder blends. The rutting and moisture susceptibilities of the asphalt mixes with high RAP content were found to be satisfactory from Hamburg Wheel Tracking (HWT) tests. A comparison of the Superpave\uae, MSCR and HWT test results is also presented in this report. In the Louisiana Tech University (LTU) study, the extensional deformation behavior of PG binders 58-28, PG 64-22, and PG 76-22 and its parameters including geometry and temperature were investigated through an extensional rheological approach using a Dynamic Shear Rheometer (DSR)-based Sentmanat Extensional Rheometer (SER). A test method and a sample preparation procedure for asphalt binders were developed as a replacement to the conventional force ductility test. With a more reproducible, significantly less material and time consuming, and with a more mechanistic approach, the developed novel test method can help improve the durability of modified asphalt pavements