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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

Production of fish powder by acid hydrolysis

Ssali, W. M. January 1984 (has links)
No description available.
2

”Mauvefärgad, dissa och tjöta” : Förändring av det språksociologiska textavsnittet i läromedel i svenska / “Mauvefärgad, dissa and tjöta” : Change in sociolinguistics part of the study material in Swedish

Persson, Sandra January 2016 (has links)
The purpose of this paper is to find out how sociolinguistics part depicted in textbooks of Swedish over time and study how much space portion is provided in three teaching aids dated 1976, 1995 and 2014. The study also intends to examine the degree of changes and what they might be due to. This study rests on two research traditions, sociolinguistics and materials analysis. Research in language sociology is extensive. Similarly, there is a tradition of research of teaching materials analysis particularly in the subject of history. Counterparts to my research is thus to be found in particular in the subject of history. For the Swedish part of the substance seems this type of research to be scant, consequently, there is a research gap that is interesting to examine more closely. This study can be seen as a contribution to the earlier tradition of research in general, but also as a contribution to the subject Swedish study materials research in particular. In order to answer these questions, a qualitative and a quantitative content analysis are made. The results show that the deployment can be greatly linked to the prevailing social context that political governance, curriculum, textbook author, etc. The results also show that the mayor differentiation lies between percentage with in the socio-linguistics text section internal than external to the teaching material. Changes that can be distinguished in the teaching material are seen mainly in the method of preparation. Learning materials go from the more stereotypical and more locked form of knowledge to become more educational and based more and more on the individual and his or her knowledge.
3

On development of production methods for transfer to SMEs

von Axelson, Jens January 2007 (has links)
The main problem in this thesis is: How should research and development results regarding production methods be represented for better adoption by SMEs? Manufacturing SMEs in Sweden have in general low profit margins and risk to go bankrupt. Different production methods could facilitate the needed performance improvement. Networking provides an arena where research and development needs could be determined and effective transfer activities could be carried through. How new production methods could be characterized and represented are presented. Several case studies, surveys and literature studies have been carried through. The results from these studies have been analyzed and compared to literature on the production method diffusion process – Dissemination-Clustering-Transfer. This analysis has resulted in a specification of requirements on how new production methods should be presented for better adoption by SMEs. One suggestion to the specification of requirements, the DFMTsme process, is described. The process is based on a repeated development procedure and follows a six-step development process in five phases. It is concluded that the DFMTsme process works. The research project is finally reviewed due to verification, validation and the contribution to knowledge. Implications for actors in the production method diffusion process as well as for policy makers are discussed. / QC 20100729
4

Modelos de otimização na produção de oleo diesel : uma aplicação industrial / Optimization models for diesel production : an industrial aplication

Ferreira, Ana Clelia 12 August 2018 (has links)
Orientador: Maria Regina Wolf Maciel / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-12T04:26:21Z (GMT). No. of bitstreams: 1 Ferreira_AnaClelia_D.pdf: 3055436 bytes, checksum: 6cdcc391dbaebe6c4d512b488fcb26ed (MD5) Previous issue date: 2008 / Resumo: O presente trabalho foi desenvolvido integrando dois conceitos tradicionais de pesquisa operacional e engenharia química, respectivamente: a otimização da cadeia logística e a otimização global de processos. O objeto de estudo é a Refinaria de Paulínia, REPLAN, da PETROBRAS, a qual participa do complexo de abastecimento de petróleo e derivados do País. Existem dois trens de produção na Refinaria; os dois têm unidades de destilação atmosférica e a vácuo, craqueamento catalítico, coqueamento retardado e hidrotratamento de diesel, onde cada unidade de processo é uma planta química completa. Cerca de 170 tanques, 3,2 milhões de m3, 48 produtos finais e 12000 alinhamentos são alguns números que ressaltam a complexidade do sistema logístico interno, para transferências, misturas e estocagem de petróleo, insumos químicos, produtos intermediários e finais. As decisões de produção da REPLAN constituem o nível local de uma estrutura hierárquica de decisões corporativa, de abrangência nacional. O nível local é subdividido tradicionalmente em planejamento mensal, programação de produção, detalhamento operacional e controle da produção. O presente trabalho propõe uma modificação na hierarquia de decisões de produção da REPLAN, acrescentando um nível entre as atividades de programação de produção e detalhamento operacional, para otimizar a produção de dois tipos de óleo diesel com horizonte de alguns dias. Etapa crucial da otimização global, o modelo matemático do sistema é descrito detalhadamente. Ele inclui as possibilidades e restrições físicas das transferências, os balanços de quantidades e qualidades, as transformações através dos hidrotratamentos e as competições por frações e correntes intermediárias. Foram desenvolvidos novos modelos empíricos de mistura para predição de duas propriedades do diesel: curva de destilação e número de cetano. O modelo geral foi implementado em MS Excel e GAMS e resolvido com o algoritmo CONOPT. Um aumento na produção média e uma redução de estoques de diesel na Refinaria, medidos no período de fevereiro a outubro de 2007, comparativamente a 2006, estão associados ao uso diário da ferramenta. / Abstract: This work has been developed integrating two traditional concepts of operational research and chemical engineering, respectively: supply chain optimization and global process optimization. The focus of the study is the PETROBRAS' Paulínia Refinery, REPLAN, which integrates the downstream petroleum and derivatives complex of Brazil. There are two production trains in the Refinery; they both have atmospheric and vacuum distillation, fluid catalytic cracking, delayed coker, and diesel hydrotreating units, whereof each process unit is a complete chemical plant. Around 170 tanks, 3.2 million m3, 48 final products and 12000 lineups are some figures that highlight the off-site local complex, for transfer, blending and storage of crude, chemicals, intermediate and final products. The production decisions at REPLAN are the local level of a corporate countrywide decision hierachy. The local level is again divided into sublevels, traditionally: month planning, daily scheduling, operation detailing and production control. This work proposes a change in the production decision hierarchy of REPLAN, adding a level between scheduling and operation detailing, with the purpose of providing an optimization tool for the production of two specifications of diesel oil along a few days horizon. Crucial step for global optimization, the system mathematical model is described in details. This includes the lineups possibilities and physical constraints, volume and property balances, property behavior through the hidrotreating units and the competition for swing-cuts and intermediate streams. It was developed new empirical blending models to predict two of the diesel properties: distillation curve and cetane number. The whole set of equations was implemented using MS Excel and GAMS, and solved with CONOPT algorithm. An increase in the average diesel production and a reduction in the diesel inventory, measured from February to October 2007, compared to 2006, are related to the daily use of the software. / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química
5

Den nya revolutionen? Additiv tillverknings potential för spridning till modeindustrin / The new revolution? Additive manufacturing’s potential of diffusion to the fashion industry

Stenford, Rebecka, Röing, Rebecca January 2016 (has links)
Teknisk utveckling och innovation är drivande för samhällets ekonomiska tillväxt. Vilja och förmåga att innovera är också avgörande för företags överlevnad då lyckosam innovation skapar konkurrensfördelar. Additiv tillverkning är en ny produktionsmetod som har potential att revolutionera hur produkter tillverkas. Tekniken kastar om förutsättningarna för hur företag konkurrerar genom att möjliggöra kostnadseffektiv tillverkning av små serier, produktion nära kundorderpunkten och kundanpassning. Modeindustrin är en komplex och hårt konkurrensutsatt bransch där företag befinner sig i en konstant strävan efter differentiering. För att nå framgång måste företag skapa fördelar gentemot konkurrenterna. Flera branscher har redan börjat använda additiv tillverkning och företag skapar framgångsrikt konkurrensfördelar genom att implementera tekniken. Inom modebranschen har dock additiv tillverkning använts begränsat och inte för produktion av konsumentprodukter. Vårt intresse väcktes för att vidare utreda huruvida det är lämpligt att implementera additiv tillverkning på bredare front. Studiens syfte är att fördjupa diskussionen kring spridning av ny teknik genom att studera additiv tillverknings potential för spridning till modeindustrin. Studien har genomförts med en deduktiv ansats där teorikärnan utgjorts av Schumpeters teorier kring innovation och Rogers teorier om innovationsdiffusion. Studien har varit av kvalitativ karaktär där empiriinsamlingen skett genom semi-strukturerade intervjuer med representanter från företag som använder additiv tillverkning samt forskare inom det textila området. Studiens slutsats är att additiv tillverkning inte lämpar sig för produktion av kläder så som vi känner dem idag. När empirin analyseras i förhållande till studiens teorier framkommer aspekter som indikerar ett flertal matchningar mellan fördelarna med additiv tillverkning och modeindustrins karaktärsdrag framkommit. Att implementera additiv tillverkning kan, i framtiden, vara en möjlighet för modeföretag att i framtiden skapa konkurrensfördelar. / Technological development and innovation are driving forces behind economic growth. Having the will and ability to innovate are also crucial factors for companies as successful innovation creates competitive advantage. Additive manufacturing is a new production process with the potential to revolutionise the way products are being manufactured. The technique disrupts competitive conditions by enabling cost-effective production of small lot sizes, production close to the decoupling point and customisation. The fashion industry is a complex and highly competitive industry, companies are in a constant quest for means of differentiation. In order to be successful, companies must create advantages over the competitors. Several sectors have already started using additive manufacturing and companies create successful competitive advantage by implementing the technology. In the fashion industry however, additive manufacturing has been used sparsely and not for production of consumer products. Our interest was awaked to further investigate whether or not it is appropriate to extend the use of this new technology. The purpose of this study is to immerse the discussion of diffusion of new technology by studying additive manufacturing’s potential of spreading to the fashion industry. The study was conducted with a deductive approach and the central theories have been Schumpeter’s theories of innovation and Rogers’ theories of diffusion of innovations. The study has been of a qualitative nature and semi-structured interviews with representatives from companies using additive manufacturing and researchers in the textile field were conducted to collect the empirical data. The conclusion is that additive manufacturing is not yet suitable for production of clothing. Nonetheless, when the empirical data was analysed in relation to the theories used, multiple matches between the benefits of additive manufacturing and the characteristics of the fashion industry were revealed. Consequently, implementing additive manufacturing can, in the future, pose opportunities for fashion companies to create competitive advantage. The thesis is written in Swedish.
6

Um documentário de afeto: espanhóis na cidade de São Paulo / Um documentário de afeto: espanhóis na cidade de São Paulo

Blanco, Maria Isabel 25 November 2009 (has links)
O indivíduo contemporâneo é fragmentado e possui múltiplas identidades. Quantas referências culturais uma pessoa pode ter? Como essas diferentes identidades convivem entre si? Esta pesquisa acadêmica teve por objetivo utilizar o documentário como meio constituinte e significante para a reflexão sobre a construção das identidades culturais de imigrantes espanhóis na cidade de São Paulo. Para tanto, produzimos um exercício prático em formato de documentário, acompanhado de uma análise que contempla a reflexão sobre o método de produção construído durante a realização do exercício. A reflexão foi feita a partir de aproximações de métodos de produção do antropólogo David MacDougall e dos realizadores Eduardo Coutinho e Trinh T.Minh-há. Do mesmo modo, servimo-nos de alguns postulados de coleta de depoimentos da História Oral, propostos por José Carlos Sebe Bom Meihy, e dos acercamentos às memórias pessoais estudados por Ecléa Bosi. Levou-se em consideração, ainda, a hipótese elaborada no contexto do laboratório Aruanda lab.doc. Esse grupo de pesquisas, que reflete sobre as diferentes formas de produção de audiovisuais de não-ficção, postula como hipótese que não há uma metodologia única ou unificadora para o documentário, na medida em que ele tem como princípio fundante o compromisso com o real. Isso obriga ao realizador que haja adaptações dos métodos planejados às condições de realização impostas pelo mundo histórico. / The contemporary man is a fragmented being with multiple identities. How many cultural references can a person have? How those different identities interact? In this academic research, documentary film was used as means of constituency and significance of the construct of the cultural identities of Spanish immigrants in the city of São Paulo, Brazil. In order to achieve that, a practical exercise in a documentary film format was conducted, and a written discussion of the method of production elected for the practice was elaborated. The reflection is based on parallels with production methods from the anthropologist David MacDougall and the filmmakers Eduardo Coutinho and Trinh Minh-ha. The analysis also profits from the Oral History collection by José Carlos Sebe Bom Meihy and from Ecléa Bosis approach to personal memories. Another source for this research was the set of hypothesis bring about in Aruanda lab.doc meetings. Aruanda is a research group, concerned with reflecting on the various forms of audiovisual production of non-fiction and documentary films. We share Aruandas main research hypothesis is that no single or unifying methodology can account for a documentary film, due to the fact that the foundating principle of documentaries is the compromise with the worlds concrete realities, which requires adaptations of the planned methods to the conditions imposed by the historic world.
7

Ημερήσια παραγωγή αβγών και ενδιαίτημα ωοτοκίας του γαύρου, Engraulis encrasicolus (Linnaeus, 1758), στο ΒΑ Αιγαίο / Daily egg production and spawning habitat of anchovy, Engraulis encrasicolus (Linnaeus, 1758), in NE Aegean

Σχισμένου, Ευδοξία 28 June 2007 (has links)
Στην παρούσα εργασία πραγματοποιήθηκε εκτίμηση της αναπαραγόμενης βιομάζας του ευρωπαϊκού γαύρου, Engraulis encrasicolus, στην περιοχή του Βορειοανατολικού Αιγαίου (Θρακικό Πέλαγος, Κόλπος Καβάλας, Στρυμωνικός Κόλπος, Λήμνος) τα έτη 2003 και 2004 με τη Μέθοδο Ημερήσιας Παραγωγής Αβγών (DEPM). Για την εφαρμογή της μεθόδου πραγματοποιήθηκαν δύο ωκεανογραφικά ταξίδια με το Ε/Σ «ΦΙΛΙΑ» κατά το μέγιστο της ωοτοκίας του γαύρου τον Ιούνιο του 2003 και του 2004. Στη διάρκεια τους συλλέχθηκαν δείγματα ιχθυοπλαγκτού για την εκτίμηση της ημερήσιας παραγωγής αβγών, ενώ πραγματοποιήθηκαν και λήψεις κατακόρυφων διατομών θερμοκρασίας και αλατότητας σε εκτεταμένο δίκτυο σταθμών. Παράλληλα, πραγματοποιήθηκαν δειγματοληψίες ενήλικων ατόμων γαύρου είτε επί του επαγγελματικού στόλου των γρι-γρι της περιοχής, είτε με την πελαγική τράτα του «ΦΙΛΙΑ», τα οποία χρησιμοποιήθηκαν για την εκτίμηση της αναλογίας φύλου, της γονιμότητας ομάδας, της συχνότητας ωοτοκίας και του μέσου βάρους των θηλυκών. Όσον αφορά στις περιβαλλοντικές συνθήκες, το 2003 παρατηρήθηκε αυξημένη στρωματοποίηση των υδάτων, χαμηλότερη επιφανειακή αλατότητα και υψηλότερες τιμές χλωροφύλλης-α, διαφορές που πιθανώς οφείλονται σε αυξημένη εκροή νερού της Μαύρης Θάλασσας. Και τα δύο έτη η βιομάζα του ζωοπλαγκτού ήταν περίπου ίδια. Μέσω απλής ανάλυσης πηλίκου για το χαρακτηρισμό του αναπαραγωγικού ενδιαιτήματος του γαύρου, βρέθηκε ότι και τις δύο χρονιές η ωοτοκία πραγματοποιήθηκε σε νερά με χαμηλή αλατότητα (<34.5), πλούσια σε χλωροφύλλη-α και ζωοπλαγκτό. Αντίθετα, τα θερμοκρασιακά εύρη κατά τις δύο χρονιές διέφεραν, γεγονός που φαίνεται να αντανακλά περισσότερο τις διαφορές θερμοκρασίας ανάμεσα στα δύο έτη παρά διαφορετική προτίμηση για ωοτοκία. Επιπλέον, το 2004 η παραγωγή αβγών ήταν μειωμένη, το πεδίο αναπαραγωγής είχε συρρικνωθεί και η ωοτοκία ήταν επικεντρωμένη στην περιοχή του Θρακικού. Για την εκτίμηση της συχνότητας ωοτοκίας πραγματοποιήθηκε ιστολογική ανάλυση των θηλυκών γονάδων του γαύρου, από την οποία προέκυψε ότι ενώ τα στάδια ανάπτυξης των υγιών ωοκυττάρων ήταν παρόμοια με περιγραφές για το είδος Engraulis mordax, τα στάδια της ατρησίας παρουσίασαν ορισμένες διαφορές. Αυτές αφορούσαν στην εμφάνιση καφε-κίτρινων χρωστικών (χαρακτηριστικό γνώρισμα της δ-ατρησίας) στο τέλος της β-ατρησίας. Επιπλέον, η απορρόφηση των κενών ωοθυλακίων διαρκούσε δύο ημέρες σε αντίθεση με παρατηρήσεις για το Engraulis mordax, όπου παρατηρούνταν και κενά ωοθυλάκια τριών ημερών, διαφορά που οφείλεται στις υψηλότερες θερμοκρασίες του ΒΑ. Αιγαίου σε σχέση με περιοχές αναβλύσεων. Οι παράμετροι των ενηλίκων που προέρχονταν από δείγματα της επαγγελματικής και πειραματικής αλιείας δεν εμφάνισαν σημαντικές διαφορές μεταξύ τους. Αντίθετα, διαφορές παρατηρήθηκαν ανάμεσα στα δύο έτη όσον αφορά στις παραμέτρους του μέσου βάρους, της συχνότητας ωοτοκίας και της γονιμότητας. Συγκεκριμένα, το 2004 τα ψάρια ήταν βαρύτερα, πιο εύρωστα και απελευθέρωναν μεγαλύτερο αριθμό αβγών ανά μικρότερα χρονικά διαστήματα. Αν λάβει κανείς υπ’όψιν ότι το 2004 η αναπαραγόμενη βιομάζα ήταν σημαντικά μικρότερη ενώ η βιομάζα του ζωοπλαγκτού παρέμεινε η ίδια, οι παραπάνω διαφορές μπορούν να εξηγηθούν από φαινόμενα εξάρτησης των παραμέτρων αυτών από την πυκνότητα του πληθυσμού (density dependence). Η αναπαραγόμενη βιομάζα το 2004 (6251t) ήταν σημαντικά μειωμένη και αντιστοιχούσε σχεδόν στο 1/3 της βιομάζας του 2003 (17600t). Η μείωση αυτή πιθανώς να οφείλεται σε συνδυασμό έντονης αλιευτικής πίεσης και χαμηλών επιπέδων στρατολόγησης της ηλικιακής κλάσης του 2003. / The spawning biomass of the European anchovy, Engraulis encrasicolus, stock in the N.E. Aegean Sea was estimated by means of the Daily Egg Production Method (DEPM) for the years 2003 and 2004. Two oceanographic surveys were conducted with the R/V “PHILIA” during the maximum reproductive activity of the anchovy population in June 2003 and 2004. Ichthyoplankton sampling and vertical profiles of temperature and salinity were performed over an extensive grid of stations. At the same time adult anchovy samples were collected either on board the commercial purse-seine fleet or by means of an experimental pelagic trawl operated by “PHILIA”. The adult samples were used to estimate parameters of the DEPM: sex ratio, mean female weight, batch fecundity and spawning frequency. Significant interannual differences were found in the environmental conditions. In June 2003 the water column was more stratified, less saline (5m) and richer in chlorophyll-α, which probably were due to larger outflow of Black Sea Water (BSW). The zooplankton biomass remained the same during 2003 and 2004. A simple quotient rule analysis was applied to characterize the spawning habitat of anchovy. In both years anchovy spawning appeared to take place in less saline waters (34.5), rich in chlorophyll-α and zooplankton. On the contrary, anchovy spawning appeared to take place over different temperature range in the two years. This rather reflects different temperature values in 2003 and 2004 than different selection for spawning. In 2004 the daily egg production was reduced, the spawning area was limited and the spawning activity took place mainly in the Thracian Sea. Histological analysis of the female anchovy gonads was carried out in order to estimate the spawning frequency. The developmental stages of healthy oocytes were similar to those of the species Engraulis mordax. However, the atresia stages were different with regard to the appearance of brown-yellow pigments at the end of beta stage atresia instead of the end of delta stage atresia. Moreover, the absorption of the postovulatory follicle lasted two days instead of three days. The higher temperatures in the N.E. Aegean Sea were responsible for the shorter duration of the postovulatory follicle absorption. There were no statistically significant differences between DEPM adult parameters calculated from purse-seine samples compared to pelagic trawl samples. On the contrary, mean female weight, fecundity and spawning frequency showed statistically significant differences between the two years. In 2004 the anchovies were in better condition and produced numerous eggs in short interspawning intervals. Since the estimated biomass was lower in 2004 while the zooplankton biomass remained stable, it seems that density-dependence phenomena could justify the interannual differences. The estimated spawning biomass in 2004 (6251t) was significantly lower compared to that of 2003 (17600t). Intense fishing effort and low levels of recruitment of the 2003 cohort are probably responsible for this decrease.
8

Um documentário de afeto: espanhóis na cidade de São Paulo / Um documentário de afeto: espanhóis na cidade de São Paulo

Maria Isabel Blanco 25 November 2009 (has links)
O indivíduo contemporâneo é fragmentado e possui múltiplas identidades. Quantas referências culturais uma pessoa pode ter? Como essas diferentes identidades convivem entre si? Esta pesquisa acadêmica teve por objetivo utilizar o documentário como meio constituinte e significante para a reflexão sobre a construção das identidades culturais de imigrantes espanhóis na cidade de São Paulo. Para tanto, produzimos um exercício prático em formato de documentário, acompanhado de uma análise que contempla a reflexão sobre o método de produção construído durante a realização do exercício. A reflexão foi feita a partir de aproximações de métodos de produção do antropólogo David MacDougall e dos realizadores Eduardo Coutinho e Trinh T.Minh-há. Do mesmo modo, servimo-nos de alguns postulados de coleta de depoimentos da História Oral, propostos por José Carlos Sebe Bom Meihy, e dos acercamentos às memórias pessoais estudados por Ecléa Bosi. Levou-se em consideração, ainda, a hipótese elaborada no contexto do laboratório Aruanda lab.doc. Esse grupo de pesquisas, que reflete sobre as diferentes formas de produção de audiovisuais de não-ficção, postula como hipótese que não há uma metodologia única ou unificadora para o documentário, na medida em que ele tem como princípio fundante o compromisso com o real. Isso obriga ao realizador que haja adaptações dos métodos planejados às condições de realização impostas pelo mundo histórico. / The contemporary man is a fragmented being with multiple identities. How many cultural references can a person have? How those different identities interact? In this academic research, documentary film was used as means of constituency and significance of the construct of the cultural identities of Spanish immigrants in the city of São Paulo, Brazil. In order to achieve that, a practical exercise in a documentary film format was conducted, and a written discussion of the method of production elected for the practice was elaborated. The reflection is based on parallels with production methods from the anthropologist David MacDougall and the filmmakers Eduardo Coutinho and Trinh Minh-ha. The analysis also profits from the Oral History collection by José Carlos Sebe Bom Meihy and from Ecléa Bosis approach to personal memories. Another source for this research was the set of hypothesis bring about in Aruanda lab.doc meetings. Aruanda is a research group, concerned with reflecting on the various forms of audiovisual production of non-fiction and documentary films. We share Aruandas main research hypothesis is that no single or unifying methodology can account for a documentary film, due to the fact that the foundating principle of documentaries is the compromise with the worlds concrete realities, which requires adaptations of the planned methods to the conditions imposed by the historic world.
9

Production of filamentous fungal biomass on waste-derived volatile fatty acids for ruminant feed supplementation and it's in vitro digestion analysis

Bouzarjomehr, Mohammadali January 2022 (has links)
Single cell proteins such as that of edible filamentous fungal biomass are considered as a promising sustainable source of animal feed supplementation. Filamentous fungi can be cultivated on different organic substrates including volatile fatty acids (VFAs) such as acetic, propionic, and butyric acids. These VFAs can be generated through the famous waste valorisation approach of anaerobic digestion (AD) as intermediate metabolites. This project investigates a sustainable approach for the production of animal feed supplementation through cultivation of fungal biomass on waste derived VFAs along with the in vitro analysis of fungal biomass digestibility as ruminant feed. In this regard, optimum conditions for the production of Aspergillus oryzae biomass on different VFAs effluents derived from anaerobic digestion process of food waste plus chicken manure (FWCKM) and potato protein liquor (PPL) at different pH, nitrogen sources, and feed mixture was studied. Accordingly, analyses showed that PPL has the highest biomass yield with 0.4 (g biomass/g consumed VFAs) based on the volatile solids (VS) by adjusting pH to 6.2. Furthermore, the digestibility of the produced fungal biomass is analysed by using three different in vitro digestion methods including Tilley and Terry (TT) method, Gas Production Method (GPM), and Nylon Bag Method (NBM) and the results are compared with the conventional feed (silage and rapeseed meal). Results obtained from different digestibility methods illustrate that different A. oryzae fungal biomass had approximately 10-15 % higher dry matter digestibility fraction compared to silage and rapeseed meal (reference feeds). Hence, these results revealed that A. oryzae fungal biomass can grow on VFAs effluents and produce protein-rich fungal biomass while this biomass has better digestibility compared to conventional feeds and confirmed the initial hypothesis of the study.
10

An analysis of precision agriculture in the South African summer grain producing areas / Hendriks J.

Hendriks, Joseph January 2011 (has links)
Both globally and locally, agriculture faces ever increasing challenges such as high input costs, strict environmental laws, decrease in land for cultivation and an increase in demand due to the growing global population. Profitability and sustainability requires more effective production systems. Precision agriculture is identified as such a system and is built upon a system approach that aims to restructure the total system of agriculture towards low input, high efficiency and sustainable agriculture. The aim of this study was to analyse the state of precision agriculture in the summer grain producing areas of South Africa, specifically the North West and Free State provinces. In order to achieve this, a literature study was conducted. During the literature study the term ‘precision agriculture’ was defined and discussed. The precision agriculture cycle and its components were explained and benefits of precision agriculture were identified. The literature study was concluded with identifying and discussing the most widely used and most beneficial technologies as well as reasons for slow adoption. Findings from the literature study were used to investigate the state of precision agriculture locally. In order to achieve this, a quantitative approach was used and information was collected by means of an empirical study using a questionnaire. Questionnaires were distributed to farmers using selling agents of an agricultural company that is well represented in the targeted areas. The data was then statistically analysed. The survey showed that only 52% of summer grain producing farmers in the North West and Free State provinces of South Africa practises precision agriculture as defined in the v literature study. The study also revealed that the majority of precision agriculture farmers are over the age of 40, have more than 16 years of farming experience, are well educated, cultivate more than 1,000 hectares and uses none or little irrigation. The most commonly used precision agriculture technologies were grid soil sampling and yield monitors. The perception among most of the farmers was that precision technologies are not very affordable, not easily available and that it lacks proper testing with regards to efficiency. The group of summer grain–producing farmers that have correctly implemented precision agriculture as per definition stated that the benefits they derived from precision technologies include reduction in input costs, increased outputs and improved management skills. Too high implementation costs and technologies not providing enough benefits were among the main reasons farmers do not implement precision agriculture. It was concluded that a significant effort and amount of work is needed to increase the use of precision agriculture among summer grain–producing farmers in the targeted areas. A consolidated effort from government, agricultural institutions and agricultural companies will be needed to achieve this goal. Implementing precision agriculture as a system will require education (from primary to tertiary institutions) and improved marketing strategies. Only then will precision technologies be able to help meet the future demands placed on the agriculture sector. / Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2012.

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