Gasificación de pellets de madera en un reactor en flujo ascendente

El trabajo presenta los resultados de la gasificación de madera pelletizada de abedul en un reactor discontinuo de lecho ascendente. En los experimentos realizados se cargo el gasificador y se realizo el ensayo sin volver a alimentar el gasificador. Es decir se gasificó solo una carga. Se varió la carga utilizada (3 y 4 kg de madera pelletizada) y el flujo de aire (entre 1.1 m3/h y 2.6 m3/h). El gas producido por la gasificación esta compuesto de CO2, CO, H2, CH4 y hidrocarburos livianos. Las mayores concentraciones de los gases producidos por la gasificación y ricos en energía son 19% de CO, 7% de H2, 4 % de C4, y 1% de hidrocarburos livianos [C2 (etano, eteno y acetileno)]. El efecto predominante del aumento del flujo de aire es una mayor temperatura en el gasificador. El proceso de gasificación mejora debido a una mayor temperatura y a un aumento de la cantidad de dióxido de carbono producida por una mayor combustión. A mayor velocidad de gasificación aumenta la producción de monóxido de carbono y el contenido calorífico del gas producido es mayor. La cantidad de líquidos aumenta con el flujo de aire.QC 2012020

Determination of cisplatin using liquid chromatography - mass spectrometry in blood plazma

Cisplatīns ir pirmais platīnu klases saturošais pretvēža medikaments.Šīs klases platīna kompleksi reaģē in vivo,saistās ar DNS un izraisa DNS šķērssaistīšanos, kas gala rezultātā izraisa šūnu apoptozi.Cisplatīns ir ķīmijterapijas zāles,kas tiek izmantotas,lai ārstētu dažādu veidu audzējus,ieskaitot galvas un kakla audzējus,urīnpūšļa,sēklinieku,dzemdes kakla audzējus, kā arī sīkšūnu plaušu audzējus.Darba mērķis ir,izmantojot jaunākās paaudzes šķidrumu hromatogrāfijas-masspektrometrijas iekārtu,noteikt cisplatīna daudzumu asins plazmā un noskaidrot cisplatīna farmakokinētiskos parametrus–Cmax,t1/2,CL,AUC,MRT un sadalījuma tilpumu(V) pacientiem ar plaušu vēzi,kuri saņēma ķīmijterapijas kursu ar intravenozo Cisplatīna infūziju.Iegūtie rezultāti liecina,ka visiem pacientiem maksimālā koncentrācija bija 2487,03 µg/mL,t1/2 33,98 h,V 139,81 L,AUC 49,59 mg-h/l,CL 3,06 L/h un MRT 48,93 h.Atslēgas vārdi:cisplatīns,šķidruma hromatogrāfijas–masspektrometrijas metode,farmakokinētika,farmakodinamikaCisplatin is a first platinum-based class anticancer drug. This class of platinum complexes response in vivo, binds to DNA and DNA causing crosslinking which ultimately results in cell apoptosis. Cisplatin is a chemotherapy drug that is being used to treat different cancer types, including head and neck tumors,bladder,testicular,cervical tumors,and small cell lung tumor. The aim of the work is using the latest generation liquid chromatography - mass spectrometry equipment to determine the amount of cisplatin in plasma and clarify the pharmacokinetic parameters of cisplatin-Cmax,t1/2,CL,AUC,MRT and distribution volume(V) of the patients with lung cancer,who treated with chemotherapy regimen with intravenous cisplatin infusion.The results showed that all patients had a maximum concentration of approximately-2487.03 µg/mL,t1/2 33.98 h,V 139.81 L,AUC 49.59 mg-h/l,CL 3.06 L/h and MRT 48.93 h. Key words:cisplatin,liquid chromatography-mass spectrometry method,pharmacokinetic,pharmacodynamic

FIXED BED UPDRAFT GASIFICATION OF BIOMASS

The paper presents the initial work performed in a newly built updraft gasifier. Densified woody biomass, birch, in form of pellets with a diameter of 8 mm and a length between 5 and 15 mm has been used as a raw material for batch autothermal gasification using air as an oxidation agent. The main objectives were to study the effect of the treatment conditions on the distribution of the products and the composition of product gas to establish the suitability of the gasifier to produce combustible gas with sufficiently high calorific value.The amount of the biomass used in the experiments was varied between 1 and 4 kg and the flow rate of the oxidation agent, air, was varied from 1,1 to 2,6 m3/h. Increased airflow rates favored higher temperatures, however, excessively high airflow rates resulted in fast consumption of the biomass and it also favored combustion over gasification and thus formation of lower amounts of combustible products. High airflow rates caused also higher yields of liquid products, due to the shorter residence time of the tar-rich gas in the gasifier and thus unfavorable conditions for tar cracking.QC 2012020

Assessment of analgesic methods after hemorrhoidectomy

Palielināti hemoroidālie mezgli ir viena no izplatītākajām proktoloģiskām saslimšanām. Hemoroidālās slimības galvenā problēma, ka nav izstrādāta pēc iespējas vienkāršāka, mazinvazīva un radikāla ārstēšanas metode, kuru varētu veiksmīgi pielietot dažādās hemoroidālās slimības stadijās, dažādu pacientu grupām, tai skaitā arī ambulatori. Klasiskā izpildījumā hemoroīdektomija ir viena no vissāpīgākajām operācijām pirmajās 24 stundās, tāpēc problemātiski izvēlēties atsāpināšanas metodi, kas nodrošinātu pietiekamu, vienmērīgu atsāpināšanas medikamentu koncentrāciju asinīs. Darba mērķis: Atrast optimālāko pēcoperācijas atsāpināšanas metodi slimniekiem pēc hemoroīdektomijām Milgana – Morgana metodes. Slimnieki un metodes: Prospektīvajā pētījumā iekļauti divdesmit slimnieki, kuriem veikta hemoroīdektomija pēc Milgana - Morgana metodes. Pamatojoties uz atsāpināšanas metodi pirmajās 24 stundās, slimnieki sadalīti divās grupās: pirmās grupa slimniekiem veikta nepārtraukta epidurālā atsāpināšana ar narkotisko zāļvielu Fentanilu un lokālo zāļvielu Bipivakaīns, kur abi preparāti atšķaidīti ar fizioloģisko šķidrumu. Otrās grupas slimniekiem veikta nepārtraukta intravenozā atsāpināšana ar narkotisko zāļvielu Fentanilu, kas atšķaidīts ar fizioloģisko šķidrumu. Rezultāti: Pamatatsāpināšanas efektivitāte pirmajās 24 stundās pēc operācijas, pirmās grupas pacientiem, kuriem veikta epidurālā atsāpināšana septiņiem pacientiem tā ir pietiekama, trijiem bija nepieciešamā papildus. Otrās grupas pacientiem, kuriem veikta intravenozā atsāpināšana, pieciem pacientiem tā pietiekama, bet pieciem bija nepieciešama papildus. Pirmās grupas vienam pacientam nepietiekamas atsāpināšanas, iemesls bija neizdevās epidurālās telpas punkcija. Blaknes no pamatatsāpināšanas netika konstatētas. Visas blaknes bija tikai no papildatsāpināšanas medikamentiem. Pirmajā grupā blaknes bija vienam pacientam, bet otrajā grupā trim pacientiem. Visiem pacientiem blaknes izpaudās ar slikto dūšu un vemšanu, pacienti atzīmēja konkrētu medikamentu, Promodols. Galīgas hemoroīdektomijas atsāpināšanas izmaksas vienām pacientam pirmajā grupā ir 41 lats 96 santīmi, otrajā grupā 16 lati 20 santīmi. Statistiski ticamas atšķirības starp pacientu dzimumu, vecumu, hemoroidālo stadiju, operācijas ilgumu un hospitalizācijas ilgumu netika konstatētas. Secinājumi: Neviena no nepārtrauktām atsāpināšanas metodēm nav absolūti efektīva, ka mono pamatatsāpināšanas metode, jo abos gadījumos pastāv papildatsāpināšanas nepieciešamības risks. Nepastāv statistiski ticamās atšķirības starp epidurālas un intravenozas atsāpināšanas efektivitātem. Epidurāla un intravenoza atsāpināšana ir droša, jo blaknes netika konstatētas. Blaknes atsāpināšanas gadījumā izraisa papildatsāpināšanas medikamenti. Epidurāla atsāpināšana ir ievērojami dārgākā nekā intravenoza atsāpināšana. Pamatojoties uz līdzīgo atsāpināšanas efektivitāti un blaknēm, bet ievērojami zemāku pašizmaksu un vienkāršāku realizāciju, nepārtraukto intravenozo atsāpināšanu var rekomendēt, ka pamatatsāpināšanas metodi hemoroīdu operācijas gadījumā.SUMMARY The study „ Assessment of analgesic methods after hemorrhoidectomy” was developed by medical student Līga Tatjana Šumilova, foreman was Assoc. prof. Arnolds Jezupovs. Hemorrhoidal disease is a commonly diagnosed among proctological diseases and world wide. The most common problem in treating hemorrhoidal disease is, upto present it still lacks radical treatment method. Post opeartive pain within 24 hours of opeartion is the main concern in hemorrhoidectomy because it is problematic to find the the appropriate analgesia method to maintain same analgesia medication concentration in blood. The study aim was: to find the most optimal post opeartive analgesia method in Milligan-Morgan hemorrhoidectomy. Patients and Methods : The prospective study consist of 20 patients who underwent Milligan-Morgan hemorrhoidectomy. Patients were divided into two groups based on method of analgesia used in first 24 hrs. In Group 1 patients underwent Epidural anesthesia with narcotic analgesic Fentanyl and local analgesic Bupivacaine which was diluted in physiologic solution.In Group 2 patients underwent intravenous anesthesia with Fentanyl diluted in physiologic solution. Results: Most effective analgesia method within 24 hours after operation was Group 1 patients, In which epidural analgesia was sufficient for seven patients and three patients received excessive analgesia. In Group 2, In which intravenous analgesia was suffient for five patients, where as rest of the five patients received excessive analgesia. Complications was recorded in patients who received extra analgesia. No complications was recorded in patients who didnt receive extra analgesia. Only one patient had complication from Group one and three patients had complication from Group 2.In both groups complications manifested as nauses and vormitting and it was noted one concrete medication which resulted in complication was Tramadol.Net cost for hemorrhoidectomy analgesia for a single patient in Group one was 41Ls and 96 cents and in Group 2 was 16 Ls 20 cents. Patients gender, age, stage of hemorrhoid, duration of operation and duration of hospitalization was not statistically significant. Conclusion: Both methods of analgesia in hemorrhoidectomy was not completely effective since extra analgesia had to be used. Both epidural and intravenous analgesia are safe because complication was due to extra analgesic medication. Epidural analgesia seems to be expensive than intravenous analgesic medications

Preliminary tests with a birch wood pellets up-draft air gasifier

In Sweden and Cuba a variety of biomass have being investigated for energyconversion through termochemical processes into solid, liquids and gaseous products. Biomass gasification in fixed bed seem to be attractive option for the conversion ofagricultural and forest residues into gases suitable for use as alternative fuel in gasengines in rural areas, heat or electricity production. This paper discusses the performance characteristics of a up - draft gasifier withBirch wood pellets. The bench scale gasifier was designed and built in the Royal Istitute of Technology, Sweden. A series of parameters, such as the gas and liquids yields, temperatures and ash yield were measured as a function of the time.QC 2012020

Teaching of German as a Foreign Language using Accurate Learning Strategies in the Context of Experimental Learning

Diplomdarba tēma ir ”Vācu valodas kā svešvalodas apguve atbilstoši mācīšanās uztveres tipam eksperimentālās mācību metodes ietvaros”. Diplomdarbā tiek apskatīti eksperimentālie mācīšanās tipi vācu valodas apguves procesā, izmantojot gramatikas un tulkošanas metodi. Darbā ietvertas anotācijas latviešu, vācu un angļu valodās, ievads, teorētiskā daļa ar 5 nodaļām un apakšnodaļām, praktiskā daļa ar 6 nodaļām un apakšnodaļām, secinājumi, tēzes un izmantotās literatūras saraksts. Pielikumā ir prakses laikā izmantotie materiāli un stundu apraksti. Darbā tika izpētīts, ka asimilējošais (domātāja) mācīšanās tips vācu valodas stundās, kurās izmanto gramatikas un tulkošanas metodi, sasniedz labākus panākumus nekā pārējie eksperimentālie mācīšanās tipi. Diplomdarba teorētiskajā daļā tiek analizēta pedagoģiskā un metodiskā literatūra par diplomdarba tēmu. Praktiskā daļa ir izstrādāta, pamatojoties uz prakses laikā skolā vācu valodas stundās veikto pētījumu, pielietojot gramatikas tulkošanas metodi,The theme of the graduation paper is “German as acquisition of the foreign language according to the perceptive type in the framework of the experimental teaching methods.” In the graduation paper experimental teaching methods, in the acquisition process of the German, are examined, using the method of the grammar and translation. The work comprises annotation in Latvian, English and German, introduction, theoretical part with 5 chapters and subchapters, practical part with 6 chapters and subchapters, conclusions, theses and references. Appendix contains materials and description of the lessons during the time of practice. In this paper author has studied assimilating (thinker) acquisition type in the lessons of the German, where the method of grammar and translation were used and which gained better achievement than other experimental acquisition types. In the theoretical part of the paper is analyzed pedagogical and methodological literature according to the theme of the graduati

Estudio termodinámico y dimensionamiento de un gasificador downdraft para um sistema de cogeneración compacto en comunidades aisladas

The gasification system has been used for manyyears ago. It has demonstrated a good way for to solveenergetic problems for isolated communities. In thispaper, is studied the gasification system associated tointernal combustion engine. Are considered technicaland economical aspects for the system design forapplications in rural localities where the electricityenergy is not possible since economical and socialviewpoint. In this manner social contribution andeconomical benefits can be determinated.Qc 2012020

BIOMASS TORREFACTION

This paper presents a work on biomass torrefaction performed in a laboratory unit with a reactor tube of a length of 0.5 m and an inner diameter of 0.04 m. The experiments are conducted with miscanthus, birch, salix as well as with wood and straw pellets. The reactor was heated to the selected temperature (230°C, 250°C or 280°C) and kept at the final temperature for a period of 1, 2 or 3 hours. The effect of the raw material, temperature, and residence time on the properties of the torrefied products is studied. The torrefied biomass products are characterized with elemental composition, energy content, moisture content, ash content and volatile fraction. The gaseous products are also analysed. The type of biomass influenced the product distribution. During torrefaction biomass undergoes changes in physical and chemical properties. The fixed carbon content and energy density increase with both time and temperature of torrefaction, while the yield on a weight basis decreases. The torrefied biomass has hydrophobic properties and a higher calorific value than the raw material.QC 2012020

BIOMASS TORREFACTION

This paper presents a work on biomass torrefaction performed in a laboratory unit with a reactor tube of a length of 0.5 m and an inner diameter of 0.04 m. The experiments are conducted with miscanthus, birch, salix as well as with wood and straw pellets. The reactor was heated to the selected temperature (230°C, 250°C or 280°C) and kept at the final temperature for a period of 1, 2 or 3 hours. The effect of the raw material, temperature, and residence time on the properties of the torrefied products is studied. The torrefied biomass products are characterized with elemental composition, energy content, moisture content, ash content and volatile fraction. The gaseous products are also analysed. The type of biomass influenced the product distribution. During torrefaction biomass undergoes changes in physical and chemical properties. The fixed carbon content and energy density increase with both time and temperature of torrefaction, while the yield on a weight basis decreases. The torrefied biomass has hydrophobic properties and a higher calorific value than the raw material.QC 2012020

A low cost & safe system of hydrogen production utilizing NaBH4 and CoO catalysis

The objective of this study was to evaluate the hydrogen production through hydrolysisof sodium borohydride (NaBH4) utilizing catalysts containing CoO. The reactant is safe and stable(when dry) at room temperature. Few works and studies have presented results of investigationsutilizing catalysts containing cobalt; however utilizing catalysts containing CoO were not found yet.In this work simple and cheap hydrogen generation system was developed having reactions atnormal conditions of temperature and pressure. A solution containing a gravimetric composition of10% wt. NaOH, 10% wt. NaBH4 and 80% wt. H2O was utilized. The reaction was carried out atvarious times using the same catalyst to evaluate its performance. This catalyst presented highrates of hydrogen production, especially at its start-up (about 99% of the theoretical hydrogenvolume was produced) at room temperature. After start-up, e.g., when more solution was put, rateof hydrogen production decreased having its production performance also decreased. Probablythis fact occurred due to the formation of the solid phase products such as NaBO2 which might fillthe porous catalyst structure; decreasing the catalytic area. This catalyst is suggested in situationswhere high production rates are necessary such as start-up of fuel cells.QC 2012020