952 resultados para OPERATIONAL PROCEDURES
Flavonoids extraction from Alpinia zerumbet (Pers.) Burtt et Smith leaves using different procedures
Resumo:
The current study aims to verify the best method for a rapid and efficient extraction of flavonoids from Alpinia zerumbet. Dried leaves were extracted using distillated water and ethanol 70% by extraction methods of shaking maceration, ultrasonic, microwave and stirring. By the application of TLC and reversed-phase HPLC techniques the rutin and kaempferol-3-O-glucuronide were detected. Ethanol 70% was more efficient for flavonoids extraction than water. No significant yielding variation was verified for ultrasonic, microwave and stirring methods using ethanol 70% (11 to 14%). Relative concentration of rutin and kaempferol-3-O-glucuronide, respectively, was higher by ultrasonic (1.5 and 5.62 mg g-1 dried leaves) and by microwave (1.0 and 6.64 mg g-1 dried leaves) methods using 70% ethanol. Rapid and simplified extraction proceeding optimize phytochemical work and acquisition of secondary metabolites.
Resumo:
Efficient designs and operations of water and wastewater treatment systems are largely based on mathematical calculations. This even applies to training in the treatment systems. Therefore, it is necessary that calculation procedures are developed and computerised a priori for such applications to ensure effectiveness. This work was aimed at developing calculation procedures for gas stripping, depth filtration, ion exchange, chemical precipitation, and ozonation wastewater treatment technologies to include them in ED-WAVE, a portable computer based tool used in design, operations and training in wastewater treatment. The work involved a comprehensive online and offline study of research work and literature, and application of practical case studies to generate ED-WAVE compatible representations of the treatment technologies which were then uploaded into the tool.
Resumo:
ABSTRACT The climate change, the quest for sustainability and the strong environmental pressures for alternatives to traditional fossil fuels have increased the interest in the search and use of renewable energy sources. Among them stands out the biomass of charcoal coming from renewable forests, widely used as a thermal reductant in the steel industry in the detriment of the use of mineral coal coke. This study aimed to compare different operating procedures of immediate chemical analysis of charcoal. Seven essays to immediate chemical analysis were compared, spread between procedures performed by Brazilian companies and laboratories, the test described by NBR 8112 and one realized with a thermogravimetric analyzer (TGA) using the parameters of the NBR 8112. There were significant differences in the volatiles matter content and consequently in the fixed carbon contents found. The differences between the procedures and the NBR 8112 were caused by an excess burning time, a mass sample above or below the standard or inappropriate container used for burning. It observed that the TGA appraisal of the volatiles content must be carried out with a burning time equal to 2 minutes to obtain results similar to those of the NBR 8112 norm. Moreover, the ash content values were statistically identical and the particles size did not influence the differences between means.
Resumo:
Painelaitteet ja kemikaaliputkistot ovat yleisiä varsinkin kemian alan yrityksissä. Omista-jan ja haltijan on tiedettävä niihin liittyvä lainsäädäntö, ja osattava soveltaa niitä käytän-töön. Työssä on selvitetty painelaitteisiin ja kemikaaliputkistoihin liittyvän lainsäädännön olen-naisin sisältö. Nykyisin painelaitteiden määräaikaistarkastuksia voidaan korvata painelait-teen seurannalla ja kunnonvalvontajärjestelmällä. Mitä se käytännössä tarkoittaa, ja onko Suomessa mahdollisuutta kuinka laajasti hyödynnetty? On tärkeää tuntea painelaitteiden ja kemikaaliputkistojen vikaantumismekanismit ja kunnonvalvontamenetelmät, jotta yritys voi luoda omaan toimintaympäristöön soveltuvan kunnonvalvontajärjestelmän tai paine-laitteiden seurannan. On pyrittävä siihen, että ongelmat havaitaan, ennen kuin vaurio syn-tyy. Kunnonvalvontajärjestelmän luomiseen ja ylläpitoon voidaan hyödyntää painelaittei-den riskiperusteiseen kunnossapitoon ja tarkastukseen tarkoitettua menettelyä. Työssä on tarkemmin käyty läpi menettelyn sisältö. Kustannustehokkuus ja tuotantolaitteiden käytettävyys ovat nousseet tärkeiksi osa-alueiksi kilpailukyvyn takaamiseksi. Painelaitteiden tarkastuksista ja muista painelaitteisiin ja ke-mikaaliputkistoihin liittyvistä ennakkohuolloista syntyvät kustannukset ovat merkittäviä. Näihin kohdistuvia kustannussäästöjä voidaan saavuttaa monin keinoin huonontamatta kuitenkaan turvallisuutta. Työssä on selvitetty kohdeyrityksen painelaitteet ja kemikaali-putkistot. Lisäksi on käyty läpi nykyinen tarkastusjaksotus, keskeisimmät viat ja tarkastuk-siin liittyvää kustannushistoriaa. Lopputuloksena on syntynyt esiselvitys ja kemikaaliputkistojen hankkimista helpottavaa tietoa. Esiselvityksen avulla kohdeyritys voi yhdessä kunnossapitoyrityksen kanssa laatia strategian painelaitteiden kunnossapidolle ja tarkastuksille. Merkittäviä kustannussäästöjä on saavutettavissa ehdotetuilla jatkotoimenpiteillä, vaikka päädyttäisiin edelleen painelait-teiden tarkastuksien osalta noudattamaan olemassa olevaa käytäntöä.
Resumo:
The use of fertilizers and solid amendments in agriculture generates special interest for their effect on crop productivity, as well as for their environmental impact. The efficient use of these products demands knowing their physical and mechanical properties, the storing conditions effect and the operational characteristics of the metering systems used in the fertilizing equipment. In this context, the present study was developed with the purpose of evaluating the operational characteristics of different fertilizing metering systems and to determine the adequate metering system-product operational parameters, using powder lime, powder gypsum, granular 10-30-10 (N-P-K), and granular urea. Operational differences were established among four types of commercial fertilizer metering systems, including wire auger, star-shaped feed wheel, feed screw and ridged traction wheel. The study found that the unloading rate depends directly on the fertilizer metering system's rotating speed and is affected by particle size, repose angle, bulk density and moisture content of the applied product. The wire auger and star-shaped feed wheel metering systems were adequate for the distribution of powder products and the feed screw for granulated fertilizers. Furthermore, theoretical and experimental characteristic equations were established, defining curves for calibration and handling of the products plus the rotating speed range in which a better distributing behavior was achieved.
Resumo:
Potato is an important crop plant throughout the world. Harvesting is a fundamental step in its production system. Maybe, it is the most complex and expensive operation. Thus, the objective of this work was to compare the cost of the mechanized and semi-mechanized harvest, the operational capacity and the production losses during the potato harvest process. The work was accomplished in a commercial farming, cultivated under pivot system, in the municipal district of Perdizes - MG, Brazil. A completely randomized design with two treatments was used: mechanized and semi-mechanized harvest. The mechanized harvest used a self-propelled harvester. In the semi-automated harvest, a digger mounted on tractor was used and the potato was manually harvested. It was concluded that the cost of mechanized harvest was 49.03% lower than the cost of semi-mechanized harvest. On average, the harvester had a work for 23 workers in manual harvest. Mechanized harvest showed losses of 2.35% of potato yield, while the semi-mechanized harvest showed losses of 6.32%.
Resumo:
The use of no tillage system associated with the crop-livestock integration is an alternate managing that promotes the accumulation of dry matter in the soil, an essential fact to make the system sustainable and profitable. The aim of this study was to evaluate the operational performance of a planter-tractor set on maize straws intercropped with Urochloa, in different seeding modes. The soybean crop was seed on the intercropping of two forage species (Urochloa brizantha and Urochloa ruziziensis) in five cropping systems: MBL (Maize with Urochloa in the maize seeding row, mixed with base fertilizer and deposited at 0.10 m), MBE (Maize with Urochloa seeded between rows at the same day of seeding maize), MBC (Urochloa between rows of maize seeded with the covering fertilizer at the V4 stage), MBLA (Maize with Urochloa by broadcast seeding at the V4 stage ) and MS (Single Maize: control). The following variables were evaluated: dry mass of maize straw, dry mass of forages and total dry mass of straw; and for the operational parameters the speed of seeding, wheel slippage, traction force and average power at the drawbar. The results showed that the amount of straw produced by maize intercropping with Urochloa, interferes in the operational performance of the tractor-planter at the operation of soybean seeding, i.e., areas with higher amount of straw promote greater energy demand, as well as higher wheel slippage.
Resumo:
Citrus orchards are very important in Brazil, especially in São Paulo State, where occupy an area of 600,000 ha approximately. To identify sustainability degree of citrus production system, an energy analysis allows evaluating efficiency of direct and indirect applied inputs. Thus, this study aimed to evaluate citrus production system under energetic point of view, in which invested energy is paid back with citrus production; being compared within three scenarios for operational field efficiency. As result, by sensitivity analysis was determined that fuel was the main energy demander, followed by pesticides and fertilizers. In operational work capacity analysis, all combinations between efficiency (minimum, typical and maximum) and yield levels became positive in the seventh year, except for the combination minimum efficiency and 10 % less yield, positive in the eighth year. The best combination (maximum efficiency and 10 % more yield) has promoted investment payoff around the sixth and seventh year. By this study, it is possible to determine the total energy demand to produce citrus and indentify the applied inputs that need more attention by the decision-makers. Labor and seedlings can be ommited for further studies with citrus, since they were irrelevant. Management of agricultural machinery may pose an important role on decreasing environmental impact of citrus production.
Resumo:
ABSTRACT The aim of this study was to evaluate the effects of modifying the maintenance programming of equipment used in sugarcane mechanical harvesting, by transferring actions that can be planned to periods when machines are inactive due to meal breaks and other working shift transitions stoppages. A simulation model was developed to represent the maintenance procedures of combines, haulouts, and other vehicles used by a harvest team. Scenarios were tested using alternatives for interventions such as refueling, lubrication and harvester blade replacement, enabling strategies to be focused towards better utilization of cutting, loading, and transport (CLT) system equipment. As a result, it was possible to remove one combine and two haulouts, while maintaining current daily production. The maintenance time for harvesters, which refers to corrective maintenance and the transfer of remaining interventions for periods of inactivity, was reduced from 10.0% to 3.5% over the useful period. This study indicates that maintenance management in the sugarcane sector enables the expanded use of equipment, leading to the greater productivity of the CLT system.
Resumo:
This master’s thesis aims to examine the relationship between dynamic capabilities and operational-level innovations. In addition, measures for the concept of dynamic capabilities are developed. The study was executed in the magazine publishing industry which is considered favourable for examining dynamic capabilities, since the sector is characterized by rapid change. As a basis for the study and the measure development, a literary review was conducted. Data for the empirical section was gathered by a survey targeted to chief-editors of Finnish consumer magazines. The relationship between dynamic capabilities and innovation was examined by multiple linear regression. The results indicate that dynamic capabilities have effect on the emergence of radical innovations. Environmental dynamism’s effect on radical innovations was not detected. Also, dynamic capabilities’ effect on innovation was not greater in turbulent operating environment.
Resumo:
Although securities lending is an important function of the financial markets, it has not received that much academic attention. This study examines the evolution of European securities lending and risk management with an emphasis on the development of collateral management, the function responsible for reducing credit risk. The effects of the recent financial instabilities are also considered. The evolution of the Finnish securities lending market is examined in more detail through a case-study. This study can be classified as a constructive qualitative case study. The initial practical knowledge comes from the author's own experience and additional insight and theoretical background is acquired through a literature review. The case study is based on research, semi-structured interviews and a brief analysis of numerical data. The main observation of this study was that securities lending is now recognized as more of an investment management discipline than an operational support function. The recent financial instabilities have resulted in an increased focus on risk and transparency. In securities lending this is directly reflected in collateral management guidelines and procedures. Collateral management has become increasingly technologically developed and automated. Collateral optimization initiatives have been started to make the process more efficient, liquid, and cost effective. Although securities lending is generally an OTC-market with no standard market place, centralized exchange-like models have been introduced. Finnish securities lending has now shifted towards the more common global OTC model. Although the Finnish securities lending industry has developed, and the main laws governing it (tax legislation) have changed, there is still need for development. There are still not many Finnish participants involved and due to legal issues most securities loans are collateralized with cash and not securities (e.g. government bonds).
Resumo:
Objective: this study aims to explore the experience of Brazilian surgeons on Unintentionally Retained Foreign Bodies (RFB) after surgical procedures. Methods: A questionnaire was sent to surgeons by electronic mail, between March and July 2012. The questions analyzed their experience with foreign bodies (FB), foreign bodies' types, clinical manifestations, diagnoses, risk factors and legal implications. Results: in the 2872 eligible questionnaires, 43% of the surgeons asserted that they had already left FB and 73% had removed FB in one or more occasions, totalizing 4547. Of these foreign bodies, 90% were textiles, 78% were discovered in the first year and 14% remained asymptomatic. Among doctors with less than five years after graduation, 36% had already left a FB. The most frequently surgical procedures mentioned were the elective (57%) and routine (85%) ones. Emergency (26%), lack of counting (25%) and inadequate conditions of work contributed (12.5%) to the occurrence. In 46% of the cases patients were alerted about the FB, and 26% of them sued the doctors or the institution. Conclusions: challenging medical situations, omission of security protocols and inadequate work conditions contributed to RFB. However, RFB occurs mostly in routine procedures such as cesarean or cholecystectomy, and at the beginning of the professional career, highlighting, particularly in poorest countries, the need for primary prevention. Textiles predominated causing clinical repercussions and they were diagnosed in the first postoperative months. Surgeons were sued in 11.3% of the RFB cases.
Resumo:
In this work mathematical programming models for structural and operational optimisation of energy systems are developed and applied to a selection of energy technology problems. The studied cases are taken from industrial processes and from large regional energy distribution systems. The models are based on Mixed Integer Linear Programming (MILP), Mixed Integer Non-Linear Programming (MINLP) and on a hybrid approach of a combination of Non-Linear Programming (NLP) and Genetic Algorithms (GA). The optimisation of the structure and operation of energy systems in urban regions is treated in the work. Firstly, distributed energy systems (DES) with different energy conversion units and annual variations of consumer heating and electricity demands are considered. Secondly, district cooling systems (DCS) with cooling demands for a large number of consumers are studied, with respect to a long term planning perspective regarding to given predictions of the consumer cooling demand development in a region. The work comprises also the development of applications for heat recovery systems (HRS), where paper machine dryer section HRS is taken as an illustrative example. The heat sources in these systems are moist air streams. Models are developed for different types of equipment price functions. The approach is based on partitioning of the overall temperature range of the system into a number of temperature intervals in order to take into account the strong nonlinearities due to condensation in the heat recovery exchangers. The influence of parameter variations on the solutions of heat recovery systems is analysed firstly by varying cost factors and secondly by varying process parameters. Point-optimal solutions by a fixed parameter approach are compared to robust solutions with given parameter variation ranges. In the work enhanced utilisation of excess heat in heat recovery systems with impingement drying, electricity generation with low grade excess heat and the use of absorption heat transformers to elevate a stream temperature above the excess heat temperature are also studied.