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  • 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

The systematic synthesis of energy-efficient thermochemical cycles and chemical heat pumps

Lauerhass, Lance. January 1978 (has links)
Thesis--Wisconsin. / Vita. Includes bibliographical references (leaves 123-124).
2

Manufacturing of synthetic soda ash.

Madima, Takalani. January 2009 (has links)
<p>The aim of the project was to study the manufacturing of synthetic soda ash (sodium carbonate, Na2CO3) on an industrial scale. Currently all Soda ash that is used in South Africa for manufacturing glass is imported at a high cost, and the company Nampak Wiegand Glass (South Africa) is investigating the possibility to locally manufacture synthetic soda ash. About 75% of soda ash is synthetically produced from either the Leblanc process, Solvay process, Modified Solvay (Dual) process or dry lime process. This study concentrated on the Solvay process on a laboratory scale for eventual input into a larger pilot plant. The produced material was analyzed using analytical techniques such as FTIR (Fourier Transform Infrared spectroscopy), Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma Atomic Emission spectroscopy (ICP-AES). There are certain standard requirements for impurities in the soda ash, and this needed to be measured and determined what changes to the process will bring the impurities to the required minimum standard. Environmental issues around the manufacturing process were also studied. After completing of the laboratory experiments and the extraction of required data from the results, Nampak will use the information to decide on a followup to the building of a small pilot plant to further test and develop the engineering and economical aspects of a full plant. If successful a full scale manufacturing plant can be developed in South Africa for producing soda ash.&nbsp / This study thus will not only help Nampak Wiegand Glass in finalizing the decision to go ahead, but its result will also benefit other companies that use the soda ash in oil refining, water treatment, pulp and paper, chemical industry etc. Some parts of the work done will be proprietary to Nampak and subject to confidentiality agreement.</p>
3

Manufacturing of synthetic soda ash.

Madima, Takalani. January 2009 (has links)
<p>The aim of the project was to study the manufacturing of synthetic soda ash (sodium carbonate, Na2CO3) on an industrial scale. Currently all Soda ash that is used in South Africa for manufacturing glass is imported at a high cost, and the company Nampak Wiegand Glass (South Africa) is investigating the possibility to locally manufacture synthetic soda ash. About 75% of soda ash is synthetically produced from either the Leblanc process, Solvay process, Modified Solvay (Dual) process or dry lime process. This study concentrated on the Solvay process on a laboratory scale for eventual input into a larger pilot plant. The produced material was analyzed using analytical techniques such as FTIR (Fourier Transform Infrared spectroscopy), Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma Atomic Emission spectroscopy (ICP-AES). There are certain standard requirements for impurities in the soda ash, and this needed to be measured and determined what changes to the process will bring the impurities to the required minimum standard. Environmental issues around the manufacturing process were also studied. After completing of the laboratory experiments and the extraction of required data from the results, Nampak will use the information to decide on a followup to the building of a small pilot plant to further test and develop the engineering and economical aspects of a full plant. If successful a full scale manufacturing plant can be developed in South Africa for producing soda ash.&nbsp / This study thus will not only help Nampak Wiegand Glass in finalizing the decision to go ahead, but its result will also benefit other companies that use the soda ash in oil refining, water treatment, pulp and paper, chemical industry etc. Some parts of the work done will be proprietary to Nampak and subject to confidentiality agreement.</p>
4

Manufacturing of synthetic soda ash

Madima, Takalani January 2009 (has links)
Magister Scientiae - MSc / The aim of the project was to study the manufacturing of synthetic soda ash (sodium carbonate, Na2CO3) on an industrial scale. Currently all Soda ash that is used in South Africa for manufacturing glass is imported at a high cost, and the company Nampak Wiegand Glass (South Africa) is investigating the possibility to locally manufacture synthetic soda ash. About 75% of soda ash is synthetically produced from either the Leblanc process, Solvay process, Modified Solvay (Dual) process or dry lime process. This study concentrated on the Solvay process on a laboratory scale for eventual input into a larger pilot plant. The produced material was analyzed using analytical techniques such as FTIR (Fourier Transform Infrared spectroscopy), Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma Atomic Emission spectroscopy (ICP-AES). There are certain standard requirements for impurities in the soda ash, and this needed to be measured and determined what changes to the process will bring the impurities to the required minimum standard. Environmental issues around the manufacturing process were also studied. After completing of the laboratory experiments and the extraction of required data from the results, Nampak will use the information to decide on a followup to the building of a small pilot plant to further test and develop the engineering and economical aspects of a full plant. If successful a full scale manufacturing plant can be developed in South Africa for producing soda ash. This study thus will not only help Nampak Wiegand Glass in finalizing the decision to go ahead, but its result will also benefit other companies that use the soda ash in oil refining, water treatment, pulp and paper, chemical industry etc. Some parts of the work done will be proprietary to Nampak and subject to confidentiality agreement. / South Africa
5

Caractérisation et modélisation d'un procédé pilote de captage de CO2 par carbonatation des saumures alcalines et séparation des phases en colonnes de flottation / Characterization and modeling of a CO2 capture pilot process by carbonation of alkaline brines and phase separation in a flotation column

Piriou, Patrice 03 April 2014 (has links)
Le procédé Solvay génère d’énormes quantités de saumures résiduaires au pH alcalin contenant portlandite, brucite et silicates de calcium hydratés. La carbonatation conduit à un abaissement du pH, ce qui favorise la formation de deux phases majoritaires : la calcite et le gypse. L’objectif de la thèse est de valoriser les saumures résiduaires carbonatées par séparation des phases en colonne de flottation. L’étude de la carbonatation en réacteur batch, puis en colonne de carbonatation pilote montre qu’il est préférable de ne pas carbonater les saumures résiduaires jusqu’à l’équilibre thermodynamique. En effet, la mise en solution de métaux lourds intervient à partir d’un pH de l’ordre de 7,5, ce qui limiterait les rejets des saumures dans l’environnement. En outre, une carbonatation brusque et incomplète est souhaitable pour une meilleure séparation des phases par flottation. Les essais de flottation réalisés sur une colonne de 7,6 cm de diamètre et de 3 m de haut ont montré une faisabilité de la séparation des deux minéraux calciques avec l’oléate de sodium comme collecteur malgré une abondante littérature incitant à la prudence. La différence entre la taille des particules de carbonates et celle des particules de sulfates et leurs hydratations de surfaces, ainsi qu’une force ionique élevée du milieu permettent une bonne séparation des phases. Une étude des saumures synthétiques permet de mettre en évidence le rôle des cations métalliques (nature, rayon, charge…) sur la coalescence des bulles dans les conditions dynamiques et dans un milieu à forte force ionique. Une étude des paramètre de fonctionnement effectué sur une colonne de 30,5 cm de diamètre et de 10 m de haut ont permis la modélisation du procédé de flottation en colonne dans le but de proposer une procédure de dimensionnement du procédé industriel. La confrontation des résultats de simulation aux résultats réels permet la détermination des intensités des microprocessus de flottation (attachement/détachement), et conduit à la proposition d’une installation industrielle avec deux colonnes de flottation en série / Solvay process generates huge amounts of waste brines at alkaline pH containing portlandite, brucite and calcium silicate hydrates. Carbonation leads to lowering of pH which favors formation of two predominant phases: calcite and gypsum. The aim of this thesis is to develop carbonated waste brines valorization by phase separation in flotation column Study of carbonation in a batch reactor and in a carbonation pilot column shows it is preferable not to carbonate waste brines until thermodynamic equilibrium. Indeed dissolution of heavy metals occurs from a pH of about 7.5 thereby limiting discharge of brines in the environment. In addition, a sudden and incomplete carbonation is appropriate for phase separation by flotation. Flotation tests carried out in a 7.6 cm diameter and 3 m high column showed feasibility of the separation of the two calcium minerals using sodium oleate as a collector despite abundant literature for caution. The differences between the particle size of carbonates and sulfates and their surface hydration, as well as the high ionic strength of the medium allow an efficient separation of phases. Study of synthetic brines highlights the role of metal cations (nature, radius, charge…) on bubble coalescence in dynamic conditions in an environment with high ionic strength. Study of operation parameter performed on a 30.5 cm diameter and 10 m high column enabled the modeling of the column flotation process in order to provide a scale-up procedure of industrial process. Comparison of simulation results with actual results allows the determination of intensities of flotation subprocesses (attachment/detachment), and led to the proposal of an industrial plant with two flotation columns in series
6

How Human Resource Professionals Use Electronic Channels to Communicate CSR : A case study focused on Solvay's French industrial sites

Fournet, Clara, Pauly, Marissa January 2015 (has links)
Corporate Social Responsibility (CSR) has become a large concern for many companies with the rise of globalization. Oftentimes, companies are encouraged to communicate CSR externally, but not internally. This research focuses upon the internal communication of CSR, specifically how Human Resource (HR) professionals use electronic channels to communicate to employees. The scope of this research is focused solely upon HR professionals within Solvay’s French industrial sites, which produce chemicals. This research utilizes a case study to answer the research questions, which are how HR professionals electronically communicate CSR to employees, and what limitations may arise from this. Five HR Managers were interviewed from different French industrial sites. This research found that electronic channels are used as a complementary method of communication within industrial sites. HR professionals communicate to employees in two ways: directly or indirectly through an intermediary. To provide more clarity to the research problem, an electronic communication model was developed specifically for industrial sites. This model provides a framework for how HR professionals communicate CSR to employees, along with the limitations of this form of communication within industrial sites.
7

Der Erdfall vom 12. Januar 1939 in Westeregeln

Bartzack, Harald 25 July 2023 (has links)
No description available.
8

L'industrie chimique française et ses mutations, 1900-1931. / The French chemical industry and its changes, 1900-1931

Langlinay, Erik 02 December 2017 (has links)
L’industrie chimique française est une industrie qui apparait alanguie au début du siècle et distancée par l’Allemagne. Elle connait cependant une croissance, plus lente, et un certain nombre de transformations notamment au point de vue de la recherche. Elle croît à l’ombre d’un système d’ententes généralisée et du dur labeur des ouvriers. Quand la guerre éclate en 1914, elle est mal préparée et doit effectuer une transformation rapide. Sa montée en puissance se fait grâce à un effort d’outillage et un développement du travail intensif où les travailleurs coloniaux paie un cher prix. Les approvisionnements anglais et américains sont essentiels pour sa production. La guerre terminée l’industrie chimique française doit se reconvertir. Elle pense, avec l’aide des pouvoirs publics, le faire grâce au Traité de Versailles. Cependant la crise de 1920-1921 montre les fragilités de cette industrie. Le retour à la croissance entre 1922 et 1929 s’accompagne à partir de 1925 d’une concurrence accrue de la part de l’Allemagne qui a rationnalisé ses structures. La croissance se fait principalement sur le marché national. En fin de période, la recherche scientifique commence à s’organiser au sein des entreprises. Toutefois la transformation capitalistique c’est imparfaitement faite. Le secteur reste dispersé et continue d’employer une forte main d’œuvre immigrée, seule capable d’accepter les tâches les plus dures. / The French Chemical industry appears in the beginning of the century as a backward industry compared with the german one. Indeed there is a slow growth and a a certain number of progress, in research for instance. The Chemical Industry is structured by a general system of cartels and harsh labour. At the outbreak of the War, the French Chemical industry is ill prepared and has to shift rapidly. It’s improvment is made through the basic development of traditionnal factories and an intensification of work due to colonial workforce for the most. At the end of the war, the chemical industry as to convert to civil markets. The 1920-1921 crisis shows the fragility of this industry. When the economic growth is back in 1922-29 the German chemical is more competitive thane ever having rationalized its structures. Thus the inner market is developped. At the end of the period, scientific research is rising. Nevertheless the capitalistic transformation is far for being made. The branch is still divided in archaïc (foreign workforce) and modern trends.

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