Optimización de absorción de Dioxido de Carbono en bebida empleando Venturi

El objetivo de esta investigación fue la construcción de un módulo experimental que utiliza un inyector Venturi y un lecho empacado para conseguir un grado de carbonatación adecuado que en la práctica industrial son cuatro volúmenes de dióxido de carbono por cada volumen de bebida carbonatada. Los resultados experimentales para un refresco con 10.5 º Brix, a una temperatura de 6 ºC +/- 1 ºC, una presión manométrica de 1.85 bar, y para un caudal de 7.2 L / min, fue posible incorporar cuatro volúmenes a la bebida de carbón. dióxido de carbono por cada volumen de refresco. Los resultados permiten utilizar el Venturi acoplado al lecho empacado como una adecuada configuración compacta que facilita una mayor absorción debido a la formación de microburbujas de dióxido de carbono ofreciendo una alta área de contacto entre las fases y homogeneización dentro del lecho empacado logrando niveles de carbonatación similares al nivel industrialTrabado de investigacio

Notes on the Nesting Biology of the Small Carpenter Bee Ceratina smaragdula (Hymenoptera: Apidae) in Northwestern Pakistan

The nesting biology and some foraging activities of the familiar, brilliant metallic green, small carpenter bee Ceratina (Pithitis) smaragdula (F.) (Hymenoptera: Apidae) is documented from the northwestern-most extent of its natural distribution, as the species is a potentially important pollinator of leguminous and cucurbit crops in the region. Numerous nests around the village of Ismaila, Swabi, Khyber Pakhtunkhwa Province, Pakistan, were observed and sampled from Jun through Aug 2012. Nest details were recorded and foraging times on various floral species were documented, with bees preferentially nesting in wooden stalks of Ravenna grass (Saccharum ravennae L.; Poales: Poaceae), life cycles lasting 28 to 32 d, and conditions offering the potential for easy management. The importance of such studies on wild bees in Pakistan is stressed, as are the development of biotic surveys on bees and the training of regional melittologists, coupled with outreach activities. Resumen La biología de la anidación y algunas actividades de forrajeo de la pequeña abeja carpintera Ceratina (Pithitis) smaragdula (F.) (Hymenoptera: Apidae) de tipo familiar y brillante color verde metálico está documentado desde el punto mas noroeste de su distribución natural, ya que la especie es potencialmente un importante polinizador de legumbres y cucurbitáceas en la región. Se observaron numerosos nidos alrededor del pueblo de Ismaila, Swabi, Khyber Pakhtunkhwa Provincia, Pakistán, y se tomaron muestras desde junio hasta agosto del 2012. Los detalles de la anidación fueron registrados y se documentaron los tiempos de forrajeo sobre diversas especies florales, con las abejas preferentemente anidando en los tallos de madera de pasto de Rávena (Saccharum ravennae L.; Poales: Poaceae), los ciclos de vida duran de 28 a 32 dias, y las condiciones que ofrecen el potencial para un fácil manejo. Se destaca la importancia de este tipo de estudio sobre las abejas silvestres en Pakistán, igual que el desarrollo de sondeos bióticos sobre las abejas y la formación de melitólogos regionales, junto con actividades de extensión

Characterization of Surface Deformation Behavior, Mechanical and Physical Properties of Modified-clay Bricks

The demand for building material is ever increasing owing to population growth. Compacted clay bricks are an important integral building material especially for low cost durable and affordable housing segment. This is a valued building material since its properties can be modified to suit various loading conditions.  In this paper, the mechanical and physical properties of clay bricks modified with varying proportions of sawdust and polystyrene are determined. Increment of non-clay material proportion in the modified-clay bricks increases their porosity and water absorbency while their bulk densities, compressive and flexural strengths decreases. The use is made of Particle Image Velocimetry (PIV) method to assess the surface deformation behavior of the modified-clay bricks under uniaxial compressive loading. The distribution of surface deformation as assessed through PIV method is relatively uniform in pure-clay bricks while modified-clay bricks indicates a non-uniform deformation localized near the loading point at low strains. The strain distribution progressively spread out in the modified-clay brick as the failure point is approached. Keywords: Modified-clay brick, Digital Image Correlation, deformation, Particle Image Velocimetry, Characterisation

Modernization and expansion of the technological line at the Bělice quarry

Tato diplomová práce se zabývá modernizací a rozšířením technologické linky lomu Bělice na výrobu drceného kameniva. Úpravy linky jsou navrženy na základě laboratorních fyzikálně mechanických zkoušek kamene z lomu v porovnání s vyráběným drceným kamenivem výrobní linkou. Cílem modernizace a rozšíření linky je příznivě ovlivnit tvarový index zrn drceného kameniva ve výrobě a tím zvýšit zájem firem vyrábějících betonové směsi a obalované kamenivo. Tvarový index zrn jednotlivých frakcí pro tato použití je dán příslušnými normami. Vhodnou úpravou výrobní linky lze dosáhnout zlepšení parametrů tvarového indexu. V úvodu práce je popsán lom, charakter ložiska, způsob těžby a stávající linka. Je zde uvedeno i několik poznatků ze stávajícího provozu lomu a výrobní linky, pro které zde navrhuji technická zlepšení.This diploma thesis deals with upgrading and extending the technological line of the quarry Bělice for the production of ground rock. Modifications of the line are designed on the basis of laboratory physical-mechanical testing of the stone from the quarry in comparison with the ground rock produced by the present line. The aim of the upgrading and extending the line is to favourably affect the shape index of ground rock grains in the production and thus to increase demand for it by companies producing concrete mixtures and covered gravel. The shape index of the grains of the constituents for those applications is set by relevant regulations. Appropriate modification of the production line can yield improvement of the parameters of the shape index. The introduction describes the quarry, the deposit character, the mining method and the present line. Several finding from the present quarry and production line operation is mentioned.542 - Katedra hornického inženýrství a bezpečnostivelmi dobř

Polyfunctional Modifiers for Bitumen and Bituminous Materials with High Performance

© 2018 Alim Feizrakhmanovich Kemalov et al. Over the last decade increase in capacity and the intensity of vehicular traffic has increased manifoldly, including heavy trucks, super singles, and higher tire pressures, resulting in significant increase of dynamic loads on the road surface which in turn lead to high quality requirements for bitumen in order to avoid premature wear and failure of asphalt concrete pavements. One of the possibilities to increase the quality of bitumen is to use special additives and modifiers that can provide a high adhesion to mineral filler and inhibit the aging and degradation processes in the asphalt coating. To achieve this, in the present study composite modifiers based on bisimidazolines derivatives were synthesized. The developed polyfunctional modifier (PFM) of complex action provides enhanced thermal stability, significantly improves the adhesion between bitumen binder and aggregates, and also improves the physical-mechanical properties of the asphalt concrete. Based on the test results it is recommended to use the synthesized samples of the PFM additive with complex action in asphalt mixtures for road paving

Assuring potato tuber quality during storage: A future perspective

Potatoes represent an important staple food crop across the planet. Yet, to maintain tuber quality and extend availability, there is a necessity to store tubers for long periods often using industrial-scale facilities. In this context, preserving potato quality is pivotal for the seed, fresh and processing sectors. The industry has always innovated and invested in improved post-harvest storage. However, the pace of technological change has and will continue to increase. For instance, more stringent legislation and changing consumer attitudes have driven renewed interest in creating alternative or complementary post-harvest treatments to traditional chemically reliant sprout suppression and disease control. Herein, the current knowledge on biochemical factors governing dormancy, the use of chlorpropham (CIPC) as well as existing and chemical alternatives, and the effects of pre- and post-harvest factors to assure potato tuber quality is reviewed. Additionally, the role of genomics as a future approach to potato quality improvement is discussed. Critically, and through a more industry targeted research, a better mechanistic understanding of how the pre-harvest environment influences tuber quality and the factors which govern dormancy transition should lead to a paradigm shift in how sustainable storage can be achieved

PEMANFAATAN EKSTRAK DAUN KEMANGI (Ocimumafricanum) SEBAGAI BAHAN ADITIF PADA PEMBUATAN SABUN KERTAS DENGAN VARIASI SUHU DAN KOMPOSISI EKSTRAK

Pandemi yang disebabkan oleh virus COVID-19 merupakan masalah besar yang dihadapi masyarakat di seluruh dunia, termasuk Indonesia. Virus dapat menyebar melalui benda yang sudah terkontaminasi oleh droplet dari penderita. Selain itu virus juga dapat menyebar tanpa menunjukkan gejala. Mencuci tangan dengan menggunakan sabun dan air merupakan salah satu upaya untuk mencegah penyebaran virus COVID-19. Sabun terbentuk dari campuran garam natrium atau kalium dengan minyak hewani atau lemak nabati. Pembentukan sabun merupakan proses saponifikasi yang merupakan reaksi antara trigliserida dengan alkali sehingga menghasilkan gliserol. Salah satu inovasi dalam pembuatan sabun adalah sabun kertas. Sabun kertas merupakan sabun yang mudah dibawa karena bentuknya yang kecil dan tipis. Namun produksi sabun kertas di Indonesia masih jarang ditemukan dan produksi sabun kertas saat ini banyak ditemukan di negara Cina dalam skala industri yang besar. Sifat antiseptik pada sabun dapat dihasilkan dengan penambahan bahan lain, seperti ekstrak daun kemangi (Ocimum africanum). Daun kemangi mengandung mengandung senyawa flavonoid, saponin, dan tanin. Penelitian ini bertujuan untuk menghasilkan produk sabun kertas yang sesuai dengan karakteristik SNI 3532:2016 dan mendapatkan formulasi sabun kertas yang optimal. Proses pembuatan sabun kertas menggunakan variasi suhu 50, 60, 70, 80, dan 90 °C serta komposisi daun kemangi 2 ml dan 5 ml. Analisis yang dilakukan untuk menentukan karakteristik sabun adalah uji kadar air, uji bahan tak larut dalam etanol, uji asam lemak bebas, uji pH, dan uji organoleptik. Hasil analisis menunjukkan bahwa terdapat tiga sampel yang memenuhi karakteristik SNI, yaitu variasi suhu dan komposisi ekstrak 60°C dan 2 ml, 80°C dan 2 ml, serta 80°C dan 5 ml. Sampel dengan formulasi terbaik terdapat pada suhu 80°C dan komposisi ekstrak 2 ml. Hasil analisis menunjukkan nilai kadar air 0,3504%, bahan tak larut dalam etanol 1,79%, asam lemak bebas 0,282%, dan pH 9,

Evaluation of poultry manure, cattle dung, water and cattle urine-based composts on soil chemical properties, growth and yield of Amaranthus cruentus L.

The inclusion of cattle urine in compost preparation will improve compost quality, particularly with respect to nutrient composition. Field experiments were conducted at the organic farm of the Federal University of Agriculture, Abeokuta, Ogun State in 2014 and 2016 to evaluate the ef­fects of water and cattle urine composts, sole poultry manure and cattle dung on post-harvest soil properties, growth and yield of Amaranthus cruentus. Treatments used were: compost derived from poultry manure + rice husk with water as source of moisture at 2.5, 5.0, 6.5 and 7.5 t ha-1, (PRW2.5, PRW5, PRW6.5 and PRW7.5 respectively), compost derived from poultry manure + rice husk with cattle urine as source of moisture at 2.5, 5.0, 5.4 and 7.5 t ha-1 (PRU2.5, PRW5, PRW5.4 and PRW7.5 respectively) and control. Post-harvest soil was analyzed for chemical properties, agronomic parameters and yield of Amaranthus cruentus were evaluated. Results showed that the application of PRU5.4 resulted in highest values for most of the agronomic parameters in both years, while the competition for highest values of post-harvest soil parame­ters was between PRW5 and PRW6.5. The highest values of Amaranthus cruentus yield in both years resulted from the application of PRU5.4 and PM3

Prevention of defects during tube bending

Bakalářská práce popisuje nejčastěji se objevující defekty vznikající při ohýbání dílců trubek. První část bakalářské práce se věnuje podrobnému průzkumu těchto nežádoucích jevů. V druhé části je uveden komplexní výčet možností redukce defektů. Pro jednotlivé eliminační metody je uvedena vhodnost a podmínky použití. Závěrem práce je potom přiřazení možností eliminace k jednotlivým typům defektů.The bachelor thesis describes the most occurring defects of tube´s component bending. The first part of this thesis is focused on a detailed research of these unwanted phenomenons. The second part contains complete list of possibilities in the defects reduction. There are quoted the suitability and the terms of use for an individual eliminative methods in the second part of this thesis, too. The last part of this bachelor thesis contains classifying of elimination possibilities to the particular types of defects.

Antimicrobial modification of PLA scaffolds with ascorbic and fumaric acids via plasma treatment

An optimal medical scaffold should be biocompatible and biodegradable and should have adequate mechanical properties and scaffold architecture porosity, a precise three-dimensional shape, and a reasonable manufacturing method. Polylactic acid (PLA) is a natural biodegradable thermoplastic aliphatic polyester that can be fabricated into nanofiber structures through many techniques, and electrospinning is one of the most widely used methods. Medical fiber mat scaffolds have been associated with inflammation and infection and, in some cases, have resulted in tissue degradation. Therefore, surface modification with antimicrobial agents represents a suitable solution if the mechanical properties of the fiber mats are not affected. In this study, the surfaces of electrospun PLA fiber mats were modified with naturally occurring L-ascorbic acid (ASA) or fumaric acid (FA) via a plasma treatment method. It was found that 30 s of radio-frequency (RF) plasma treatment was effective enough for the wettability enhancement and hydroperoxide formation needed for subsequent grafting reactions with antimicrobial agents upon their decomposition. This modification led to changes in the surface properties of the PLA fiber mats, which were analyzed by various spectroscopic and microscopic techniques. FTIR-ATR confirmed the chemical composition changes after the modification process and the surface morphology/topography changes were proven by SEM and AFM. Moreover, nanomechanical changes of prepared PLA fiber mats were investigated by AFM using amplitude modulation-frequency modulation (AM-FM) technique. A significant enhancement in antimicrobial activity of such modified PLA fiber mats against gram-positive Staphylococcus aureus and gram-negative Escherichia coli are demonstrated herein. © 2020 The AuthorsQatar National Research Fund (a member of The Qatar Foundation) [22-076-1-011]; Qatar University Collaborative Grant [QUCG-CAM-20/21-3]; Czech Science FoundationGrant Agency of the Czech Republic [19-16861S