Current developments and challenges of underground mine ventilation and cooling methods

The mining industry has experienced a dramatic change over the past 20 years in terms of methods and equipment as well as human resource policies. These changes have had impacts on the design of mine ventilation systems. Although feasible developments have been implemented to some extent, in some other areas ventilation planning still requires further improvements to provide a healthy work environment at a reasonable cost. The boom in energy costs has also encouraged mine ventilation designers to seek for efficient use of energy and optimization strategies. The electricity consumption by mine refrigeration plants should be reduced possibly without any adverse effects on the safety of workers. This study presents an overview of the latest techniques used by the experts to address these issues. A revision of the novel ventilation strategies and mine refrigeration methods, and their ultimate effect on efficiency and mining costs would be identified. Finally, likely future developments in the area of mine cooling are outlined

Perfusion bioreactor for liver bioengineering

End-stage organ failure has grown to become one of the key challenges for the medical community because of the high number of patients in waiting list for a transplant and the severe shortage of suitable organ donors. These, together with population ageing, have created an accumulation phenomenon of patients which increases the severity of the problem. New techniques for organ preservation, organ recovery from organs not suitable for transplant, and organ recellularization attempt to tackle this problem, appearing as some of the most promising solutions. The aim of this bachelor thesis is to continue the development of a complex liver perfusion bioreactor in order to design and develop an efficient and repeatable method for organ perfusion, decellularization and recellularization, with the final objective being the creation of a perfusion bioreactor for liver bioengineering able to be used for organ perfusion and preservation, organ decellularization and organ recellularization, able to preserve cell structure, functionality, growth and control differentiation for up to 4 weeks, while avoiding contamination and automating as much as possible the process. In order to do this, the bioreactor will include many sensors and data acquisition systems as well as control systems for pressure, flow rate, and temperature among others.Ingeniería Biomédic

Phononics: Manipulating heat flow with electronic analogs and beyond

The form of energy termed heat that typically derives from lattice vibrations, i.e. the phonons, is usually considered as waste energy and, moreover, deleterious to information processing. However, with this colloquium, we attempt to rebut this common view: By use of tailored models we demonstrate that phonons can be manipulated like electrons and photons can, thus enabling controlled heat transport. Moreover, we explain that phonons can be put to beneficial use to carry and process information. In a first part we present ways to control heat transport and how to process information for physical systems which are driven by a temperature bias. Particularly, we put forward the toolkit of familiar electronic analogs for exercising phononics; i.e. phononic devices which act as thermal diodes, thermal transistors, thermal logic gates and thermal memories, etc.. These concepts are then put to work to transport, control and rectify heat in physical realistic nanosystems by devising practical designs of hybrid nanostructures that permit the operation of functional phononic devices and, as well, report first experimental realizations. Next, we discuss yet richer possibilities to manipulate heat flow by use of time varying thermal bath temperatures or various other external fields. These give rise to a plenty of intriguing phononic nonequilibrium phenomena as for example the directed shuttling of heat, a geometrical phase induced heat pumping, or the phonon Hall effect, that all may find its way into operation with electronic analogs.Comment: 24 pages, 16 figures, modified title and revised, accepted for publication in Rev. Mod. Phy

Storage of organically produced crops (OF0127T)

This is the final report of Defra Project OF0127T. The main objective of this review was to establish best storage practice for field vegetables, potatoes, cereals and top fruit. A literature review was carried out and information was also gathered from the industry. Information relevant to growers and farmers has been drawn together to provide a comprehensive base from which technical advisory leaflets can be produced. The costs of different storage methods are provided, and case studies used wherever possible. In general, organic crops can be stored using the same methods as conventional crops but there is an increased risk that sometimes there will be higher storage losses because pesticides and sprout suppressants are not used. On the whole, specific problems with pests and diseases can be avoided using good organic husbandry techniques and by storing undamaged, healthy crops. In the case of cereals storage at correct moisture content and temperatures can avoid pests and moulds. However, there are some areas where more technical development or research would be useful and these have been identified. Relatively few organic growers store vegetables, but in order to maintain a supply of good quality UK produce throughout the year, more long term cold storage space is required (either on farm or in co-operative type stores). Based on the limited data available, economic analysis revealed that long term storage of organic vegetables has generally not been profitable. However, as the market expands in the future, it is likely that storage will become as essential for vegetables as it is for organic cereals and fruit

Epäsuoran jäähdytysjärjestelmän suunnittelu ja toteutus laboratoriotestausta varten

New products and concepts are being constantly developed in worldwide refrigeration business. Modern challenges and opportunities drive some development towards more environmentally friendly and smart refrigeration, with smaller demands for space and installation expenses. Indirect refrigeration systems have their own advantages, such as possibility of very small refrigerant charges compared to direct systems, especially with long piping and many cooling targets. Viessmann ESyCool is an advanced and comprehensive energy system for food retail stores. ESyCool system utilizes indirect refrigeration. Aim of this work is to design and implement an indirect refrigeration system for laboratory testing of various indirect refrigeration products and equipment, including some from ESyCool. Some relevant refrigeration technology and theory are also introduced, including a proper review of vapor compression, CO2 and indirect refrigeration systems. All in all, this project was successful and a working system with wanted properties was accomplished. Decades of high quality indirect refrigeration can be achieved with the project’s refrigeration plant if recommended adjustments, operation and maintenance are carried out. Based on this study, for around 10-50kW similar kind of indirect refrigeration plant projects, considerably good results can be achieved with design according to appendixes 4-7 and 10, and details described in this work. For implementation, significantly shorter installation times and a bit higher quality can be reached with means mentioned and discussed in this work. This project and its learnings can be used as a benchmark for similar custom made energy production plant projects in future, especially in refrigeration branch.Kylmä-alan globaalissa liiketoiminnassa uusia tuotteita ja konsepteja kehitetään jatkuvasti. Nykyajan haasteet ja mahdollisuudet vievät kehitystä kohti ympäristöystävällisempää ja älykästä kylmätekniikkaa, pienemmillä tilavaatimuksilla ja asennuskuluilla. Epäsuorilla kylmäjärjestelmillä on omat etunsa, kuten hyvin pienet kylmäaine lataukset verrattuna suoriin kylmäjärjestelmiin, varsinkin jos putkistoilta vaaditaan pituutta ja kylmäkohteita on monta. Viessmann ESyCool on edistynyt ja kattava energiajärjestelmä ruokakauppoihin. ESyCool järjestelmässä hyödynnetään epäsuoraa kylmätekniikkaa. Työn tarkoituksena oli suunnitella ja toteuttaa epäsuora jäähdytysjärjestelmä laboratoriotestauksen tarpeisiin. Testattavat ovat erilaisia epäsuoralle jäähdytykselle suunniteltuja tuotteita ja laitteita, joista osa sisältyy myös ESyCool-konseptiin. Työssä esitellään myös aihepiiriin liittyvää kylmä- ja jäähdytystekniikkaa ja teoriaa, mukaan lukien kunnollinen katsaus kompressori-, CO2- ja epäsuoriin jäähdytysjärjestelmiin. Kaiken kaikkiaan projekti voidaan nähdä onnistuneena ja toimiva kylmälaitos halutuilla ominaisuuksilla saatiin aikaan. Projektistamme valmistuneella kylmälaitoksella voidaan toteuttaa laadukasta epäsuoraa jäähdytystä vuosikymmeniä, kunhan jäljellä olevat pienet työt, huolto ja laitoksen operointi hoidetaan asiaankuuluvasti. Tämän tutkimuksen perusteella kylmäteholtaan noin 10-50kW:ssa samantyyppisissä epäsuorissa kylmälaitosprojekteissa voidaan päästä melko hyviin tuloksiin liitteiden 4-7 ja 10, ja tässä työssä esiteltyjen tietojen mukaisella suunnittelulla. Toteutuksen osalta voidaan päästä selvästi lyhyempiin asennusaikoihin ja hieman parempaan lopputulokseen soveltamalla tässä työssä mainittuja ja läpi käytyjä keinoja. Tätä projektia ja siitä saatuja oppeja voidaan käyttää jatkossa benchmarkkina samantyyppisissä energiantuotantolaitosprojekteissa, varsinkin kylmä-alan projekteissa

Cogeneration Unit

V diplomové práci je krok po kroce vypracováno řešení zabezpečení energetického zdroje pro typické město v Sibiřské oblasti. Data, která tvoří zadání, byla získána od zákazníka pomocí dotazníku, protože pro nás oblast v čase vypracování nebyla dostupná. Na základě informací o aktuální energetické situaci, obyvatelstvu a dřevospracujícímu průmyslu je vybrána vhodná technologie pro zabezpečení tepla a elektrické energie. Druh zdroje byl vybrán dle dostupného paliva a následně byl proveden výpočet a design en- ergetického zdoje založeného na Rankine Clausiovém cyklu. Řešení obsahuje technický i ekonomický návrh. Technické řešení ukázalo, že nejdůležitější parametry jsou spolehlivost, bezpečnost a jednoduchost řešení. Design sítí, přídavných zařízení a plánování údržby není obsahem této práce. O dalších projektových krocích pojednává závěr.This thesis deals with providing both electric power and heat for an ordinary Siberian town. On site observation and measurements to determine the local conditions were not an option. Hence information gathering is presented. It covers the energy situation for the public and for the wood processing plant. The technical part of the thesis starts with a review of an existing technology. The options are presented, and the decision is to recom- mend particular new system based on the Rankine cycle. At such distant location power source depends very strongly on the available combustible resources. This thesis presents also the evaluation of economics. The main objective was to carry out an analysis and design an adequate and economical cogeneration application where the most important criteria are reliability, safety and simplicity. Design of auxiliary equipment and heat distribution network are not in the scope of this thesis. The conclusion deals also with next recommended steps.

Eneglish for the students of Electronic Education Institute

Пособие предназначено для студентов 3 курса ИнЭО, изучающих профессиональный курс английского языка и обучающихся по заочной классической, дистанционной и гибридной формам обучения по направлению 13.03.01 «Теплоэнергетика и теплотехника»