• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 3
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Hydrolysis of Acetic Anhydride in Water/Tetrahydrofuran Co-solvent Systems Using Eyring Activation Energy Analysis.

Afolaju, Wasiu ALOWONLE, Mr, Dane, SCOTT, Dr 12 April 2019 (has links)
This study determines the activation energy parameters for the hydrolysis of acetic anhydride in water/tetrahydrofuran solutions. These values are needed for studies to quantify the effect of the bulk electrostatic environment solvent-solute interactions on the hydrolysis reaction rate. Hydrolysis of an acetic anhydride with water or under basic conditions yields acetic acid. The current study is based on simple hydrolysis of acetic anhydride which produces acetic acid decreasing the pH over time. Simple hydrolysis is monitored by measuring pH versus time at temperatures ranging from 20.0 to 35.0 oC and mole fraction of water ranging from 0.75 to 1.00. Measuring pH over time has advantages over other methods such as conductivity, UV-vis spectroscopy, temperature scanning, FTIR, calorimeter as it is simple, inexpensive and reproducible. Experimental results were used to determine activation enthalpy and entropy for hydrolysis of acetic anhydride using tetrahydrofuran as the co-solvent. These values were determined using the Eyring rate equation under iso-mole fraction and isothermal conditions. Analysis was performed to determine if the activation enthalpy and entropy are temperature dependent. Eyring plots are expected to be linear for iso-mole fractions and isothermal conditions of tetrahydrofuran.
2

Dyzelinių variklių, dirbančių antros kartos biodegalų mišiniais,eksploatacinių charakteristikų tyrimai / The research of exploitation characteristics of diesel engines running on second generation biofuel blends

Žaglinskis, Justas 17 December 2014 (has links)
Disertacijos tyrimų aktualumą lemia energijos panaudojimo efektyvumo didinimas bei aplinkos taršos mažinimas transporto sektoriuje. Darbe sprendžiami eksperimentiniai, matematinio modeliavimo ir metodologiniai uždaviniai, siekiant kompleksiškai ištirti dyzelinių variklių, dirbančių II kartos RRME, alkoholio ir dyzelino mišiniais, eksploatacinius darbo rodiklius. Disertacijoje analizuotas ir įvertintas degalų mišinių panaudojimo lengvųjų automobilių ir pagalbiniame laivo dyzeliniuose varikliuose efektas. Tiriamojo darbo problematika, tikslas, uždaviniai suformuoti išanalizavus transporto sektoriaus sandarą, svarbą oro taršos ir energijos sunaudojimo srityse bei ES strateginius planus. Laboratorijos bei eksploatacijos sąlygomis ištirti I, II kartos biodegalų ir dyzelino mišiniai. Tyrimams panaudotuose varikliuose išbandyti butanolio ir metanolio su rapso metil/butilesteriais bei dyzelino 2 ir 3 komponentų mišiniai. Išbandyti II kartos RRME mišiniai: Sėjamosios judros (lot. Camelina sativa) kartu su kiaulienos RRME ir mikro dumblių (lot. Clorella sp.). Atlikti dyzelino ir mišinių palyginamieji variklinių savybių tyrimai. Panaudojant mišinius, energijos panaudojimo efektyvumas didėja ~1–4 %; esant šiek tiek išaugusiai NOX koncentracijai, CO, CH koncentracijos sumažėjimas siekia iki 20 %, o deginių dūmingumas – 55–85 %. Įvertinti terminės ir mechaninės apkrovos kriterijai, indikuojantys variklio konstrukcinį patikimumą dirbant dyzelinu ir degalų mišiniais. Ištirta biodyzelinų... [toliau žr. visą tekstą] / The relevance of dissertation research is determined increasing efficiency of energy use and reduction of environmental pollution in the transport sector. In order to accomplish the complex research of diesel engines (running on 2nd generation FAME, alcohol and diesel blends) performance indicators the experimental, simulation and methodological tasks are solved in dissertation. The analysis and evaluation of effect of fuel blends use in passenger car and vessel auxiliary diesel engines is presented in dissertation. The problem, aim, tasks of research work formulated after analysis of transport sector structure, the importance of air pollution and energy consumption and the EU's strategic plans. The blends of 1st and 2nd generation biofuels were investigated using laboratory equipment and in the exploitation conditions. 2 and 3 component blends of diesel, methanol, butanol, rape methyl/butyl esters were tested in diesel engines. Tested 2nd generation FAME blends: False flax (lat. Camelina sativa) with pork lards FAME and sea algae (lat. Clorella sp.). The comparable research of parameters while engine ran on diesel and blends was carried out. In the case of blends use the energy efficiency increases ~1–4%; at slightly increased NOX concentration the CO and CH concentrations decreased up to 20% and exhaust smoke, and smokiness decreased – 55–85%. The evaluation of thermal and mechanical load criteria which indicate 1.9 TDI 1Z engine reliability operating on diesel fuel and... [to full text]
3

Studie snížení energetické náročnosti bytového domu / Study of energy consumption reduction of block of flats

Svoboda, Lukáš January 2014 (has links)
The goal of the thesis is firstly to get all the information about the initial state of solved block of flats, which is located on the street Merhautova 76/954 in Brno – Černá pole, in terms of constructions, energy consumption and initial state of heating system. In the second part of the thesis, where are discussed the possibilities of reduction of energy consumption, variant drafts of reduction of energy consumption and their financial costs and the choice of optimal variant. Third part deals with assement of solved block of flats in terms of sustainable built environment by using tool to rate buildings in terms of sustainable built environment - SBToolCZ, evaluation of possibility to use renewables. In the end are written summaries and recommendations.

Page generated in 0.0646 seconds