Enantioselective Esterification Of (±)-Menthol With Butyric Anhydride By Chemically Modified Candida Rugosa Lipase

Commercial lipase from Candida rugosa was chemically modified with the aim to improve its catalytic properties in organic solvents. The chemical modifiers, aldehydes and monomethoxy polyethylene glycols, were covalently linked to the lysine residues at the surface of the enzyme. Enzymatic enantioselective esterification of racemic menthol in organic solvents using butyric anhydride as acylating agent was performed with the chemically modified lipases. Different degrees of modification, organic solvents, reaction temperatures and water activity were examined for the influence on the percent yield and enantioselective formation of (-)-menthyl butyrate. The percent yield increased as the degree of modification increased but decreased slightly for the highest degree of modification. Organic solvents with log P values above 2.5 gave higher yield, however high enantioselectivity was obtained in all the organic solvents tested. The enantioselectivity towards (-)-menthol decreased considerably as the reaction temperature was increased. Enzyme derivatives exhibited better activity and enantioselectivity at high aw. The alkylated lipases showed higher thermal, solven

Effect of Time and Rate of Application of Nitrogen on The Yield of the Mexican Wheat under the Semi-arid Conditions of Tunisia

The effect of the time and rate of application of nitrogen on the yield of high yielding varieties of wheat was studied under the semiarid conditions of Northern Tunisia. Analysis of the experimental data showed that nitrogen increased the yield of wheat in most locations which were chosen for this experiment. In high rainfall areas, late application of nitrogen (tillering, jointing stages) was more effective than early applications. The optimum yield was obtained by applying 90 kilograms of nitrogen per hectare. In the medium to low rainfall area, early applications (seeding time) were more effective than the late ones. The optimum yield was obtained by applying 67 kilograms of nitrogen per hectare. The yields varied from one location to another. This variability was found to be very dependent on the amount and distribution of the rainfall, thus moisture in the soil and the residual nitrogen

Combustor liner support assembly

A support assembly for a gas turbine engine combustor includes an annular frame having a plurality of circumferentially spaced apart tenons, and an annular combustor liner disposed coaxially with the frame and including a plurality of circumferentially spaced apart tenons circumferentially adjoining respective ones of the frame tenons for radially and tangentially supporting the liner to the frame while allowing unrestrained differential thermal radial movement therebetween

Low NO.sub.x combustor

A combustor includes a dome assembly having radially outer and inner liners joined thereto and defining therebetween a combustion zone. The dome assembly includes at least one annular dome having a pair of axially extending first flanges between which are disposed a plurality of circumferentially spaced apart carburetors for discharging a fuel/air mixture into the combustion zone for generating combustion gases. An annular heat shield includes a pair of axially extending legs integrally joined to a radially extending face in a generally U-shaped configuration, with the face including a plurality of circumferentially spaced apart ports disposed concentrically with perspective ones of the carburetors for allowing the fuel/air mixture to be discharged therefrom through the heat shield. At least one of the heat shield legs includes a plurality of circumferentially spaced apart mounting holes disposed adjacent to a respective one of the dome flanges, and a plurality of mounting pins are fixedly joined to the dome flange and extend radially through respective ones of the mounting holes without interference therewith for allowing unrestrained thermal movement between the heat shield and the dome while supporting the heat shield against axial pressure loads thereon. In a preferred embodiment, the dome assembly includes three domes having respective ones of the heat shield, and respective baffles are spaced from the heat shields for providing impingement cooling thereof

Liner mounting assembly

A mounting assembly includes an annular supporting flange disposed coaxially about a centerline axis which has a plurality of circumferentially spaced apart supporting holes therethrough. An annular liner is disposed coaxially with the supporting flange and includes a plurality of circumferentially spaced apart mounting holes aligned with respective ones of the supporting holes. Each of a plurality of mounting pins includes a proximal end fixedly joined to the supporting flange through a respective one of the supporting holes, and a distal end disposed through a respective one of the liner mounting holes for supporting the liner to the supporting flange while unrestrained differential thermal movement of the liner relative to the supporting flange

Segmented combustor

A combustor liner segment includes a panel having four sidewalls forming a rectangular outer perimeter. A plurality of integral supporting lugs are disposed substantially perpendicularly to the panel and extend from respective ones of the four sidewalls. A plurality of integral bosses are disposed substantially perpendicularly to the panel and extend from respective ones of the four sidewalls, with the bosses being shorter than the lugs. In one embodiment, the lugs extend through supporting holes in an annular frame for mounting the liner segments thereto, with the bosses abutting the frame for maintaining a predetermined spacing therefrom

Energy efficient engine high pressure turbine test hardware detailed design report

The high pressure turbine configuration for the Energy Efficient Engine is built around a two-stage design system. Moderate aerodynamic loading for both stages is used to achieve the high level of turbine efficiency. Flowpath components are designed for 18,000 hours of life, while the static and rotating structures are designed for 36,000 hours of engine operation. Both stages of turbine blades and vanes are air-cooled incorporating advanced state of the art in cooling technology. Direct solidification (DS) alloys are used for blades and one stage of vanes, and an oxide dispersion system (ODS) alloy is used for the Stage 1 nozzle airfoils. Ceramic shrouds are used as the material composition for the Stage 1 shroud. An active clearance control (ACC) system is used to control the blade tip to shroud clearances for both stages. Fan air is used to impinge on the shroud casing support rings, thereby controlling the growth rate of the shroud. This procedure allows close clearance control while minimizing blade tip to shroud rubs

Analisis Pengaruh Online Customer Review, Online Customer Rating, dan Star Seller terhadap Kepercayaan Pelanggan Hingga Keputusan Pembelian pada Toko Online di Shopee

Kemampuan pelanggan dalam menilai barang secara online dan offline berbeda. Informasi barang secara online hanya dapat dilihat melalui gambar dan deskripsi. Sehingga diperlukan kepercayaan pelanggan bahwa informasi yang diberikan adalah benar. Pada situs belanja online Shopee terdapat beberapa fitur yang dapat meyakinkan pelanggan, yaitu fitur customer review, customer rating, dan star seller. Penelitian ini bertujuan untuk menentukan model, hipotesis, indikator, dan mengetahui fitur yang dapat mempengaruhi kepercayaan pelanggan hingga keputusan pembelian. Penelitian menggunakan metode Partial Least Square-Structural Equation Modelling (PLS-SEM) dengan ukuran sampel sebanyak 100 responden. Hasil analisis penelitian disimpulkan bahwa customer review, customer rating, dan star seller berpengaruh positif dan signifikan terhadap kepercayaan pelanggan. Fitur customer review memiliki pengaruh yang lebih dominan dibandingkan customer rating dan star seller. Kemudian, kepercayaan pelanggan berpengaruh positif dan signifikan terhadap keinginan membeli. Sedangkan, keinginan membeli dan sikap orang lain berpengaruh positif dan signifikan terhadap keputusan membeli. Variabel faktor situasi tidak terduga tidak mempengaruhi keputusan membeli

Asiantuntijalausunto perustuslakivaliokunnalle

HE 13/2001 vp laiksi rangaistusten täytäntöönpanosta annetun lain muuttamisesta ja eräiksi siihen liittyviksi laeiks

Julkisia hankintoja koskevien oikeudenkäyntien tehostaminen : Selvityshenkilön raportti

Markkinaoikeuden asemaa julkisten hankintojen erityistuomioistuimena ei ole syytä muuttaa. Oikeudenkäynti markkinaoikeudessa ja korkeimmassa hallinto-oikeudessa täyttää yleisesti oikeudenmukaiselta oikeudenkäynniltä vaadittavat joutuisuusedellytykset. Oikeudenkäyntiä voidaan tehostaa, mutta sen on tapahduttava perus- ja ihmisoikeuksien rajoissa. Määräajan asettamista tuomioistuinten toiminnalle ei puolleta. Osa hankintavalituksista voitaisiin säätää kuitenkin markkinaoikeudessa kiireellisiksi sekä vahvistaa prosessinjohdon ja sisäisen seurannan asemaa näiden tuomioistuinten toiminnassa. Hankintavalituksia koskevan erityissääntelyn lisäämisen mahdollisuutta tulisi harkita oikeudenkäynnin ulkoisen kuvan ja sisäisen kulun selkeyttämiseksi. Uusien valitusperusteiden esittämismahdollisuutta ja kuulemisvaatimuksen toteuttamista voitaisiin selkeyttää sekä selvittää mahdollisuutta ottaa käyttöön sähköinen oikeudenkäyntimenettely kuulemisvaatimuksen toteuttamisen yhteydessä. Oikeudenkäyntimaksun korotuksen merkityksestä oikeudenkäynnin tehostamisessa tulisi käynnistää selvityshanke. Esittelijä- ja asiantuntijajärjestelmän kehittämismahdollisuuksia voitaisiin samoin harkita. Markkinaoikeuden lainkäyttötehtävien luonteen muuttuminen olisi syytä ottaa huomioon markkinaoikeuden resursseissa. Hankintaoikaisun käyttöä hankintamenettelyn selvien virheiden korjaamisessa tulisi pyrkiä lisäämään