DEFICIT IRRIGATION TECHNIQUE FOR REDUCING WATER USE OF TOMATO UNDER POLYTUNNEL CONDITIONS

The aim of paper was to asses the use of regulated deficit irrigation (RDI) for production of two tomato cultivars (Cedrico and Abellus) in polytunnels in Serbia. RDI plants received 60% of the water that was applied to FI plants and significant saving of water for irrigation and increased in irrigation water use efficiency (IWUE) were achieved. Yield data for Cedrico cultivar showed no differences between RDI and FI, while due to the bigger sensitivity to drought, yield of Abellus was reduced under RDI. In general, fruit quality (soluble solids, titrable acidity) was sustained or improved in both cultivars under RDI. Economic analyses showed that due to the current low prices of water and electricity in Serbia, the profit increase of Cedrico, similarly to the previously trialed cultivar Amati, was not high under RDI comparing to FI. Reduction of yield and consequent profit for Abellus, indicated that for future commercial growing of tomato under RDI should be used drought resistant cultivars

Quantendynamik intramolekularer Wasserstoffbrückenbindungen in Gas- und kondensierter Phase

Title, Publications, Abstract, Contents, Acknowledgement, Curriculum Vitae 1 Introduction 1 1.1 Hydrogen Bonds 1 1.2 IR spectra of Hydrogen Bonded Systems 3 1.3 Outline of the Work 6 2 Theoretical Concepts 7 2.1 Quantum Chemistry 7 2.1.1 Hartree-Fock Theory 9 2.2.2 Density Functional Theory 12 2.2 Anharmonicity 16 2.2.1 Anharmonic Force Field Approach 19 2.2.2 Cartesian Reaction Surface Approach 25 2.2.3 CRS versus AFF 31 2.2.4 The Diabatic Representation 33 2.3 Quantum Dynamics 37 2.2.1 Isolated Quantum Systems 38 2.2.2 Open Quantum Systems 43 2.2.3 Interaction with an external field 51 3 Cascaded Ultrafast Energy Redistribution of an Intramolecular HB 53 3.1 PMME-a System with a Medium Strong Hydrogen Bond 55 3.1.1 System - Bath Coupling 69 3.2 Population Dynamics of the Cascaded Energy Relaxation 72 3.2.1 Relaxation Mechanism of ?b 75 3.2.2 Relaxation Mechanism of ?s 78 3.2.3 Concluding Remarks 82 4 HB Dynamics in a Double Minimum System 84 4.1 Model System Salicylaldimine 85 4.2 Exploring the Enol Well in SA with the AFF Method 85 4.3 The CRS Hamiltonian - Paving the Way to Chemical Reactions 93 4.4 IR Absorption Spectra for SA-H and SA-D 101 4.5 Ultrafast IR Laser Driven Dynamics 106 4.5.1 Excitation of the OH/OD Bending Motion 106 4.5.2 Dynamics of the OH/OD Stretching Vibration 113 4.6 Comparison of AFF and CRS Results 121 4.7 Would it be Possible to Control a Hydrogen Transfer Reaction? 122 5 Summary and Outlook 126 A Time Dependent Schrödinger Equation - Another Perspective 129 B The Reduced Density Operator in the Interaction Picture 132 C Anharmonic Force Fields and the B3LYP Exchange Correlation Functional 135 Bibliography 137The significance of hydrogen bonds for processes occurring in nature has prompted both experimental and theoretical investigation of their properties. In the present work we focused on modelling the dynamics of systems containing intramolecular hydrogen bonds placing emphasis on the multidimensionality of the studied phenomena. As anharmonicity represents a basic property of hydrogen bonded systems, two approaches that go beyond the standard harmonic approximation are presented: the Anharmonic Force Field (AFF) method and the Cartesian Reaction Surface (CRS) procedure. The former approach is well suited for describing processes that take place close to the equilibrium configuration, whereas the latter treats anharmonicity more rigorously, being able to account for large amplitude motions of the reactive degrees of freedom. In a first application the IR laser driven nuclear wave packet dynamics in gas phase Salicylaldimine is considered using the Multi Configuration Time Dependent Hartree (MCTDH) approach. It is suitable for handling high dimensional models, thereby being capable to delineate mechanisms that involve intramolecular energy redistribution and to explain complex absorption spectra in terms of wave packet dynamics. As a second example the dissipative dynamics of Phthalic acid monomethylester in the condensed phase is discussed. Here, the influence of the solvent is included through propagation of reduced density matrices using the Redfield approach within the Bloch limit. In this way, the competition of the intra and intermolecular interactions is studied. The combined theoretical and experimental efforts facilitated clarification of pathways for ultrafast energy relaxation in an intramolecular hydrogen bonded system for the first time. It was demonstrated that the energy redistribution after the initial excitation is a cascading process that involves both molecular and solvent modes. Finally, the issue of controlling hydrogen transfer reactions through a sequence of infrared laser pulses is addressed in the outlook.Die Bedeutung von Wasserstoffbrückenbindungen für Vorgänge in der Natur hat die Aufmerksamkeit auf die experimentelle wie auch theoretische Untersuchung ihrer Eigenschaften gelenkt. In der vorliegenden Arbeit steht die Modellierung der Dynamik von Systemen im Vordergrund, die intramolekulare Wasserstoffbrückenbindungen enthalten, wobei das Hauptaugenmerk auf der Vieldimensionalität der untersuchten Phänomene liegt. Anharmonizität ist eine wesentliche Eigenschaft von Systemen mit Wasserstoffbrückenbindungen. Hier werden zwei Ansätze, die über die übliche harmonische Näherung hinausgehen, vorgestellt: die Anharmonic Force Field (AFF) \- und die Cartesian Reaction Surface (CRS)} Methode. Die zuerst genannte Methode ist gut geeignet um Prozesse zu beschreiben, die in der Nähe der Gleichgewichtskonfiguration stattfinden, wohingegen der zuletztgenannte Zugang die Anharmonizitäten genauer beschreibt, da auch Auslenkungen der reaktiven Freiheitsgrade mit großer Amplitude beschrieben werden können. Als erste Anwendung wird die IR-Laser getriebene Wellenpaketdynamik von Salicylaldimine in der Gasphase betrachtet, wobei der Multi Configuration Time Dependent Hartree (MCTDH) Ansatz Verwendung findet. Der MCTDH-Ansatz eigenet sich besonders zur Behandlung hochdimensionaler Modelle, wodurch die Beschreibung von Mechanismen, die intramolekulare Energieumverteilung beinhalten, sowie die Erklärung komplexer Absorptionsspektren mit Hilfe von Wellenpaketdynamik möglich ist. Als zweite Anwendung wird die dissipative Dynamik von Phthalsäuremonomethylester in der kondensierten Phase diskutiert. Dabei wird der Einfluss des Lösungsmittels durch die Propagation von reduzierten Dichtematrizen unter Verwendung des Redfield-Ansatzes im Rahmen der Bloch-Näherung beschrieben. Auf diese Weise wurden die konkurrierenden intra- und intermolekularen Wechselwirkungen studiert. Die kombinierten theoretischen und experimentellen Untersuchungen ermöglichten erstmalig die Aufklärung von ultraschnellen Energierelaxationspfaden in einem System mit intramolekularer Wasserstoffbrückenbindung. Weiterhin wurde demonstriert, dass die Energieumverteilung nach ultraschneller Anregung ein kaskadenartiger Prozess ist, in den sowohl molekulare Moden als auch Lösungsmittelmoden involviert sind. Im Ausblick wird schliesslich die Kontrolle von Wasserstofftransferreaktionen durch eine Sequenz von IR-Laserpulsen diskutiert

Something for Everybody

Senior Project submitted to The Division of Arts of Bard College

Unrevealing mechanism of the thermal tautomerization of avobenzone by means of quantum chemical computations

Avobenzone (4-tert-butyl-4’-methoxydibenzoylmethane) is one of the most widely used UVA filters in cosmetic sunscreens. Reactivity of avobenzone is complex and challenging to understand, due to a presence of transient tautomers. In this contribution we study chelated enol, rotamer and keto tautomers of a reduced model of avobenzone which are involved in keto-enol tautomerization. Two thermal tautomerization mechanisms are postulated and their transient structures are discussed. The computed vertical and adiabatic electronic excitation energies of tautomers provide an additional insight into excited state properties of the tautomers. [Projekat Ministarstva nauke Republike Srbije, br. 172040 i br. ON171017

Vibrational Energy Relaxation of Phenol-Water Complex Studied in Supersonic Molecular Beam

第6回分子科学討論会, 2012年9月18日-21日, 東京大学本郷キャンパス(東京), 2A0

Are the program packages for molecular structure calculations really black boxes?

In this communication it is shown that the widely held opinion that compact program packages for quantum–mechanical calculations of molecular structure can safely be used as black boxes is completely wrong. In order to illustrate this, the results of computations of equilibrium bond lengths, vibrational frequencies and dissociation energies for all homonuclear diatomic molecules involving the atoms from the first two rows of the Periodic Table, performed using the Gaussian program package are presented. It is demonstrated that the sensible use of the program requires a solid knowledge of quantum chemistry

Study on the immunopathological effect of titanium particles in peri‐implantitis granulation tissue: A case–control study

Objectives To identify titanium particles (TPs) in biopsy specimens harvested from peri-implantitis lesions and secondarily to study the histopathological characteristics in peri-implantitis compared to periodontitis, in order to evaluate whether the presence of TPs could alter respective inflammatory patterns. Material and methods Biopsies containing granulation tissue were harvested during routine surgical treatment in 39 peri-implantitis cases and 35 periodontitis controls. Serial sections were obtained using titanium-free microtome blades. The first and last sections of the peri-implantitis specimens were used for identification of TPs by scanning electron microscopy coupled with dispersive X-ray spectrometry. Intermediate sections and periodontitis specimens were processed for descriptive histological study using haematoxylin–eosin staining and for immunohistochemical analysis using CD68, IL-6, Nf-kB and VEGF markers. Results TPs were identified in all peri-implantitis specimens as free metal bodies interspersed within granulation tissue. However, presence of macrophages or multinucleated giant cells engulfing the TPs were not identified in any specimen. Peri-implantitis granulations were characterized by a chronic inflammatory infiltrate rich in neutrophils. About half of peri-implantitis patients exhibited a subacute infiltrate characterized with lymphocytes interweaved with neutrophils and eosinophils. When compared to periodontitis, peri-implantitis tissues showed higher proportions of macrophages and a more intense neovascularization, based on significantly higher expression of CD68 and VEGF respectively. Conclusion TPs were identified in all peri-implantitis specimens, but without evidencing any foreign body reaction suggestive for direct pathological effects of TPs. The peri-implantitis granulation tissue was characterized by intense neovascularization and presence of a chronic inflammatory infiltrate dominated by plasma cells, neutrophils and macrophages

A hybrid approach for high precision prediction of gas flows

10.1007/s12667-021-00466-4Energy System