bluuebunny/crossref_metadata_2025 huggingface dataset:
Sintesis dan Karakterisasi porous carbon dari Sukrosa dengan Menggunakan Asam Sulfat dan Asam Nitrat
Authors: Istiqomah Istiqomah , Pardoyo Pardoyo , Taslimah Taslimah
Published: May 2019

Porous carbon merupakan suatu material serbaguna karena mempunyai luas permukaan yang besar dan porositas yang tinggi. porous carbon dapat dibuat dari berbagai zat yang memiliki susunan senyawa hidrokarbon seperti karbohidrat, batang kayu atau zat yang mengandung senyawa hidrokarbon lainnya dengan pemanasan temperatur tinggi serta proses aktivasi. Penelitian ini bertujuan untuk memperoleh porous carbon dari sukrosa serta menentukan karakteristik produk yang diperoleh. Produk sintesis dianalisis menggunakan spektrofotometer FTIR, X-Ray diffraction dan surface area analyzer. porous carbon yang diperoleh dari penggunaan asam nitrat meningkat luas permukaan dan volume pori berturut-turut sebesar 24%dan 25% relatif terhadap porous carbon yang dibuat dengan menggunakan asam sulfat. Adanya perlakuan kalsinasi, porous carbon yang dibuat dengan asam sulfat juga meningkatkan luas permukaan dan volume pori berturut-turut sebesar 97% dan 98%. porous carbon yang diperoleh dapat digunakan sebagai adsorben minyak goreng sisa pakai. porous carbon yang dibuat menggunakan asam nitrat mempunyai daya pemucatan terhadap minyak sisa pakai yang lebih tinggi daripada porous carbon yang lain.
Sintesis dan Karakterisasi Silica Gel dari Tetraetilortosilikat (TEOS) Menggunakan Surfaktan Polyethylene Glycol (PEG) 6000 dalam Kondisi Basa
Authors: Purwanto Agus Salim , Taslimah Taslimah , Sriatun Sriatun
Published: May 2019

Penelitian tentang sintesis silika gel dari tetraetilortosilikat (TEOS) menggunakan surfaktan polyethylene glicol (PEG) 6000 dalam kondisi basa telah dilakukan. Penelitian ini bertujuan untuk menentukan pH optimum pembentukan gel tercepat untuk sintesis silica gel dan menentukan karakter silika gel hasil sintesis. Sintesis silica gel dilakukan dengan mencampurkan tetraetilortosilikat (TEOS), etanol, aquades, NH4OH dan polietilen glikol (PEG) 6000. Penelitian ini dilakukan variasi pH 8-10 dan variasi konsentrasi PEG 6000 yaitu 0,01 g/100 mL; 0,03 g/100 mL; 0,06 g/100 mL. Silika gel hasil sintesis dikarakterisasi dengan spektrofotometer inframerah (FTIR), difraksi sinar-X (XRD) dan BET surface area analyzer. Diperoleh bahwa  pH 9 sebagai pH optimum untuk pembentukan gel. Hasil analisis difraksi sinar-X (XRD) menunjukkan bahwa silika gel adalah amorf sedangkan hasil BET surface area analyzer menunjukkan bahwa silika gel termasuk dalam mesopori dengan volume total pori dan luas permukaan spesifik silika gel tertinggi diperoleh pada pH 9 dan dengan konsentrasi PEG 6000 0,03 g/100 mL yaitu masing-masing 124,574 cm3/g dan 285,456 m2/g.
Kajian Metode Elektrofotokatalisis, Elektrolisis dan Fotokatalisis pada Dekolorisasi Larutan Zat Warna Remazol Brilliant Orange 3R yang Mengandung Ion Logam Cu2+
Authors: Febriyani Arthias Cita , Hastuti Rum , Haris Abdul
Published: May 2019

Limbah cair industri tekstil mengandung zat warna dan logam berat. Remazol brilliant orange 3R dan logam tembaga merupakan zat warna dan logam berat yang banyak terdapat pada limbah tekstil. Pembuangan limbah cair tekstil tanpa pengolahan limbah terlebih dahulu akan menyebabkan pencemaran lingkungan perairan. Metode elektrolisis, fotokatalisis dan elektrofotokatalisis merupakan metode yang dapat digunakan dalam penanganan limbah tekstil. Pada penelitian ini akan dibandingkan ketiga metode tersebut untuk dekolorisasi larutan zat warna remazol brilliant orange 3R yang mengandung ion logam Cu2+ serta mengetahui pengaruh keberadaan ion logam Cu2+ dan penyinaran lampu UV-C terhadap dekolorisasi zat warna remazol brilliant orange 3R. Hasil penelitian menunjukkan bahwa metode elektrofotokatalisis merupakan metode yang paling efektif karena mampu mendekolorisasi remazol brilliant orange 3R hingga 98,43% dan menurunkan konsentrasi ion logam Cu2+ hingga 99,35%. Keberadaan ion logam Cu2+ dan penyinaran lampu UV-C meningkatkan dekolorisasi zat warna remazol brilliant orange 3R.
Pengaruh Temperatur Pengeringan Gel terhadap Konduktivitas Elektrolit Padat NaMn2-xMgxO4
Authors: Risyanti Feni , Nuryanto Rahmad , Suyati Linda
Published: May 2019

Pembuatan elektrolit padat NaMn2-xMgxO4 dengan variasi temperatur pengeringan telah dilakukan. Tujuan penelitian ini adalah untuk mengetahui pengaruh variasi temperatur pengeringan gel terhadap konduktivitas elektrolit padat NaMn2-xMgxO4. Metode yang digunakan dalam penelitian yang dilakukan adalah metode sol-gel yang meliputi pengadukan, penguapan pada 80°C, pengeringan pada variasi temperatur 150, 160, 170, 180 dan 190°C, dan kalsinasi pada 800°C. Produk yang dihasilkan dianalisis dengan uji konduktivitas, FTIR dan XRD. Hasil pengukuran konduktivitas padatan amorf dan elektrolit padat berdasarkan variasi temperatur pengeringan menunjukkan nilai konduktivitas tertinggi diperoleh pada temperatur 170°C yaitu masing-masing 2,27 x 10-9 S cm-1 dan 22,2 x 10-9 S cm-1. Konduktivitas terendah untuk padatan amorf dan elektrolit padat diperoleh pada temperatur 150°C yaitu masing-masing sebesar 1,87 x 10-9 S cm-1 dan 12,6 x 10-9 S cm-1.
Kajian Metode Elektrofotokatalisis, Elektrolisis dan Fotokatalisis pada Dekolorisasi Larutan Zat Warna Remazol Red RB yang Mengandung Ion Logam Cd2+
Authors: Sari Rosida Puspita , Haris Abdul , Prasetya Nor Basid Adiwibawa
Published: May 2019

Limbah cair industri tekstil mengandung zat warna dan logam berat. Remazol Red RB dan logam kadmium merupakan zat warna dan logam berat yang banyak terdapat pada limbah tekstil. Pembuangan limbah cair tekstil tanpa pengolahan limbah terlebih dahulu akan menyebabkan pencemaran lingkungan perairan. Metode elektrolisis, fotokatalisis dan elektrofotokatalisis merupakan metode yang dapat digunakan dalam penanganan limbah tekstil. Pada penelitian ini akan dibandingkan ketiga metode tersebut untuk dekolorisasi larutan zat warna remazol red RB yang mengandung ion logam Cd2+ serta mengetahui pengaruh keberadaan ion logam Cd2+ dan penyinaran lampu UV-C terhadap dekolorisasi zat warna remazol red RB. Hasil penelitian menunjukkan bahwa metode elektrofotokatalisis merupakan metode yang paling efektif karena mampu mendekolorisasi remazol red RB hingga 97,85% dan menurunkan konsentrasi ion logam Cd2+ hingga 96,50%. Keberadaan ion logam Cd2+ dan penyinaran lampu UV-C meningkatkan dekolorisasi zat warna remazol red RB.
Elektrodekolorisasi Perairan Tercemar Limbah Cair Industri Batik dan Tekstil di Daerah Batang dan Pekalongan
Authors: Widayanti Galih , Widodo Didik Setiyo , Haris Abdul
Published: May 2019

Telah dilakukan elektrodekolorisasi air yang tercemar limbah industri Batik dan Tekstil di daerah Batang dan Pekalongan. Penelitian ini bertujuan untuk mendekolorisasi zat warna dalam air limbah industri batik dan tekstil dengan pendekatan elektrolisis menggunakan elektroda PbO2/Pb dan mengukur parameter pH, COD (Chemical Oxygen Demand), TSS (Total Suspended Solid), TDS (Total Disolved Solid). Penelitian dilakukan melalui elektrolisis 100 mL limbah air sungai Pekalongan dan Batang pada potensial 6,5 volt dan 8,0 volt untuk limbah sebelum di buang ke sungai. Waktu elektrolisis selama 200 menit. Hasil akhir elektrolisis dianalisis dengan Spektrometer UV-Vis dan analisis parameter pH, COD, TDS dan TSS sebelum dan sesudah proses elektrolisis. Hasil yang di dapatkan sebagai berikut: sebelum elektrolisis limbah air sungai di Pekalongan pH 6,90; COD 54,20 mg/L; TSS 20,30 mg/L; TDS 1,893 mg/L. Limbah air sungai di Batang pH 6,71; COD 56,18 mg/L; TSS 25,55 mg/L; TDS 7,393 mg/L. Limbah sebelum di buang ke sungai pH 7,32; COD 678,32 mg/L; TSS 219,15 mg/L; TDS 1,983 mg/L. Sesudah elektrolisis limbah air sungai di Pekalongan pH 6,99; COD 52,10 mg/L; TSS 2,03 mg/L; TDS 1,925 mg/L. Limbah air sungai di Batang pH 7,99; COD 69,903 mg/L; TSS10,70 mg/L; TDS 6,785 mg/ L. Limbah sebelum di buang ke sungai pH 7,56; COD 366,830 mg/L; TSS 46,50 mg/L; TDS2,235 mg/L. Hasil yang diperoleh menunjukkan dekolorisasi menggunakan elektroda PbO2/Pb berlangsung hingga 94,03% untuk limbah air sungai di Pekalongan, 96,74 % untuk limbah air sungai di Batang, 97,13 % untuk limbah sebelum dibuang ke sungai.
Sintesis Komposit Carbon Nanotubes-Polyvinyl Alcohol sebagai Bahan Prototype Rompi Tahan Peluru
Authors: Yuwono Andi Nur , Pardoyo Pardoyo , Subagio Agus
Published: May 2019

Komposit dengan struktur nano telah dikembangkan karena kekuatannya lebih baik dibandingkan dengan komposit biasa, sehingga dapat diaplikasikan sebagai bahan dalam pembuatan rompi tahan peluru. Penelitian ini bertujuan untuk mensintesis carbon nanotubes sebagai bahan dasar komposit CNT-PVA,menentukan pengaruh waktu purifikasi terhadap kemurnian carbon nanotubes dan menentukan pengaruh purifikasi terhadap kekuatan komposit yang akan digunakan sebagai bahan rompi tahan peluru. Hasil penelitian menunjukkan bahwa dengan analisis SEM, carbon nanotubes yang diperoleh adalah jenis MWNT dengan diameter tabung antara 55,5 nm – 97,3 nm. Analisis dengan menggunakan EDS menunjukkan persentase atom Fe sebelum purifikasi dan setelah purifikasi pada waktu 1 dan 3 jam adalah 3,50%, 2,43% dan 1,68%. Gugus fungsional carbon nanotubes sebelum dan sesudah purifikasi dianalisis dengan menggunakan speltroskopi FT-IR. Setelah purifikasi ditemukan adanya gugus karboksilat, yang tidak ditemui pada saat sebelum purifikasi. Hasil uji tarik pada komposit dari CNT tanpa purifikasi menunjukkan modulus Youngnya sebesar 11,151 MPa,% mulurnya 13,67%, gaya tarik maksimumnya 29,365 kgf atau 287,972 N sedangkan pada komposit dari CNT purifikasi modulus Youngnya sebesar 4,491 MPa,% mulurnya 39,95%, gaya tarik maksimumnya 28,5 kgf atau 279,490 N.
Removal of natural organic matter for wetland saline water desalination by coagulation-pervaporation
Authors: Rahma Aulia , Elma Muthia , Mahmud Mahmud , Irawan Chairul , Pratiwi Amalia Enggar , Rampun Erdina Lulu Atika
Published: May 2019

The high number of natural organic matter contain in wetland water may cause its water has brown color and not consumable. In other hand, intrusion of sea water through wetland aquifer create water become saline, notably on hot season. Coagulation is effective method to applied for removing of natural organic matter. However, it could not be used for salinity removal. Hence combination of coagulation and pervaporation process is attractive method to removing both of natural organic matter and conductivity of wetland saline water. The objective of this works is to investigate optimum coagulant doses for removing organic matter by coagulation process as pretreatment and to analysis performance of coagulation-pervaporation silica-pectin membrane for removing of organic matter and conductivity of wetland saline water. Coagulation process in this work carried out under varied aluminum sulfate dose 10-60 mg.L-1. Silica-pectin membrane was used for pervaporation process at feed temperature ~25 °C (room temperature). Optimum condition of pretreatment coagulation set as alum dose at 30 mg.L-1 with maximum removal efficiency 81,8 % (UV254) and 40 % (conductivity). In other hand, combining of coagulation-pervaporation silica-pectin membrane shows both of UV254 and salt rejection extremely good instead without pretreatment coagulation of 86,8 % and 99,9 % for UV254 and salt rejection respectively. Moreover, water flux of silica-pectin membrane pervaporation with coagulation pretreatment shown higher 17,7 % over water flux of wetland saline water without pretreatment coagulation. Combining of coagulation and pervaporation silica-pectin membrane is effective to removing both of organic matter and salinity of wetland saline water at room temperature.
SISTEM WAYFINDING MALL DI SEMARANG
Authors: Kusumasari Brigita Theora Mega , Harsritanto Bangun IR
Published: May 2019

Shopping mall merupakan salah satu  bangunan komersil yang sudah menjadi gaya hidup bagi sebagian besar masyarakat perkotaan. Masyarakat pergi mengunjungi shopping mall untuk memenuhi memenuhi kebutuhan seperti berbelanja, maupun sekedar berekreasi dan mencari hiburan. Sebagai bangunan umum yang menawarkan berbagai fasilitas dan ramai dikunjungi oleh masyarakat, shopping mall perlu dilengkapi dengan sistem wayfinding yang baik supaya pengguna bangunan tidak mengalami disorientasi. Metode penelitian yang digunakan dalam penyusunan laporan ini adalah metode deskriptif, dokumentatif, dan komparatif dimana penyusunan dilakukan dengan mengumpulkan data, menjelaskan, dan menjabarkan terhadap informasi terkait bagaimana pengaruh bahan lantai serta pemilihan bahan lantai yang baik dan murah diaplikasikan pada jalur pedestrian bagi kenyamanan dan keamanan pengguna. Wayfinding adalah kemampuan seseorang untuk bernavigasi dalam suatu lingkungan. Sistem wayfinding adalah fasilitas yang memiliki fungsi memberikan kemudahan bagi pengguna dalam bernavigasi. Sistem wayfinding yang baik dapat ditinjau melalui empat strategi, yaitu: District, Streets, Connection, dan Landmarks. Jika pengguna dengan mudah membayangkan keempat strategi tersebut dalam suatu diagram “mind map”, ketika berada dalam suatu bangunan atau lingkungan maka dapat dikatakan bahwa bangunan atau lingkungan tersebut memiliki sistem wayfinding yang efektif.
Positive and negative effects of nanoparticles on plants and their applications in agriculture
Authors: Goswami Pooja , Yadav Sonali , Mathur Jyoti
Published: May 2019

Nanotechnology is the promising field with its wide applications in biotechnology, pharmaceutical science, drug targeting, nano-medicine and other research areas. This review highlights the positive and negative impact of nanoparticles on plants and its wide applications in agricultural sciences. Effect of NPs in terms of seed germination, growth promotion and enhancement of metabolic rate has been evaluated by several scientific researches. However, NPs also exert their negative effects such as suppression of plant growth, inhibition of chlorophyll synthesis, photosynthetic efficiency etc. Effects of NPs can be either positive or negative it depending upon the plant species and type of nanoparticles used & its concentration. Modern nano-biotechnological tools have a great potential to increase food quality, global food production, plant protection, detection of plant and animal diseases, monitoring of plant growth nano-fertilizers, nano-pesticide, nano-herbicides and nano-fungicides.
Tłumaczenie biznesowe a środowiskowe –status i rola tłumacza
Authors: Krajewska Katarzyna
Published: May 2019

The aim of this article is to present “business interpreting” as such and to contrast it with conference and community interpreting. The article also discusses various roles interpreters assume in business setting and gives examples of real-life situations where it might be difficult to unambiguously decide what should be expected from an interpreter. A number of questions for further research is also asked.
Incipient Musings on Theory and Formation of Modern Korean Digraphia
Authors: Strnad William
Published: May 2019

This article explores modern Korean digraphia, its chracteristics, duality and formation. The author posits that the essential axis of argumentation of the Korean digraphic debate related to the applications of Chinese characters and Korean phonetic script was formed by the early part of the twentieth century, and would be recapitulated in the two Koreas against the backdrop of post-colonial metanarration and Cold War politics. The author asserts that the functional and synchronic nature of modern Korean digraphia was formed under the influence of the Lyotardian modernity emancipation and speculative (science) metanarratives, as well as the discourse of modern Korean nationalism, which synchronically formed in the Korean assertion of national identity and idependence, during Koreaʼs struggle against imperialism.
W mocy tekstu
Authors: Wawrzyniak Jan
Published: May 2019

The text hereby presented is written in the form of an essay and, at the same time, it promotes this form – as a particular, cognitively efficient model of philosophical as well scientific investigations. It contains analytical deliberations on the sophisticated relations between  a philosophical text and its nominal author who is governed by the internal logic of the narration and who ‘vanishes’ while writing. There are also the issues of an author’s professional methodological responsibility for the writing as well as the creative-interpretational function of addressees taken into account. Some necessary references to the philosophy of science as well as the philosophy of language are present in the essay, too. And within this scope, an explanatory narration is identified with a parameterization of the world being explained or described; and the so-called description always remains preferential. A significant part of the article contains some remarks about the Polish education system in the context of both tradition and perspectives of the development of European culture. What is particularly stressed is the role of the humanities in the process of educating young people who should be responsible enough to take care of the axio-variety of human culture in the future. Therefore, the conceptions of the so-called area ethics and culture enrichment ethics are emphasized as well.
Polsko-rosyjskie pogranicze – od regionu izolowanego do transgranicznego
Authors: Modzelewski Wojciech Tomasz
Published: May 2019

W artykule przyjęto założenie, że dwa regiony sąsiadujące, czyli posiadające wspólną, lądową granicę: województwo warmińsko-mazurskie i Obwód Kaliningradzki FR tworzą polsko-rosyjskie pogranicze. Widoczna jest ewolucja polsko- rosyjskiej granicy: od zamkniętej (do 1955 r.), poprzez selektywnie otwartą (lata 1956-1989), do granicy jako płaszczyzny współpracy (od 1990 r.). Wpływa to na ewolucję badanego pogranicza: od zamkniętego, izolowanego - do pogranicza, gdzie realizowane są wielowymiarowe, oddolne kontakty transgraniczne. Natomiast wprowadzenie w 2012 r. zasad małego ruchu granicznego i związany z tym dynamiczny wzrost ruchu granicznego służą kształtowaniu polsko-rosyjskiego regionu transgranicznego.
Polityczny oddźwięk Deklaracji o stosunku Kościoła do religii niechrześcijańskich Nostra aetate
Authors: Górzna Sylwia
Published: May 2019

Otwarcie Kościoła katolickiego na dialog z innymi religiami ma swoje źródło w Soborze Watykańskim II (1962-1965), który w wielu dokumentach wyraził pozytywny stosunek Kościoła katolickiego do religii niechrześcijańskich. Był wydarzeniem szczególnym i przełomowym w dziejach Kościoła katolickiego. Autorka przedstawiła dokument soborowy, który proponuje, aby wierni Kościoła nawiązali dialog z wyznawcami różnych religii, aby szanowali wartości obecne w tych religiach. Deklaracja o stosunku Kościoła do religii niechrześcijańskich Nostra aetate rozpoczęła proces reorientacji Kościoła wobec wyznawców różnych religii m.in. islamu i judaizmu, której podstawąjest wiara w jednego Boga (monoteizm). Należy zwrócić uwagę zwłaszcza na numer 3. tej deklaracji, który podkreśla, iż Kościół katolicki z szacunkiem odnosi się do wyznawców islamu oraz numer 4., który zawiera sformułowanie zdejmujące z Żydów odpowiedzialność za Bogobójstwo, porusza bolesną sprawę antysemityzmu, jednak nie z pobudek politycznych. Dzięki Deklaracji wielu katolików zmieniło podejście do wyznawców innych religii. Ten dokument jest świadectwem potwierdzającym szczególną troskę Kościoła o nawiązanie przyjaznych relacji z wyznawcami różnych religii m.in. islamu i judaizmu. Autorka jest przekonana, iż dokument przyczynia się do pokojowego współistnienia religii, które powinny podjąć służbę na rzecz pokoju między narodami, co stanowi o jego politycznym wymiarze.
Struktura semantyczna pojęć „wolność sumienia i religii”, „wolność sumienia i wyznania” (część II)
Authors: Hordecki Bartosz
Published: May 2019

W tekście zajęto się problematyką złożoności znaczeniowej terminów „wolność sumienia i religii”, „wolność sumienia i wyznania”. Chcąc scharakteryzować semantyczny potencjał obu wyrażeń, przeanalizowano warstwę emotywnąnazw „wolność”, „sumienie”, „religia”, „wyznanie”, a także pokrewnych „sumieniu” („przekonanie” oraz „świadomość”), jak również „religii” („światopogląd”).
Powiązania literackie Polski i Azji Centralnej: literatura polska w przekładach na łamach uzbeckiego czasopisma „Jahon adabiyoti”
Authors: Genjemuratov Bahtiyar
Published: May 2019

Autor omawia przykłady aktualnego stanu kulturalno-literackiej współpracy narodu polskiego i uzbeckiego. Jego zdaniem w dobie globalizacji elity twórcze czują potrzebę stałego dialogu i wzajemnych powiązań różnych państw i całego świata w ogóle, czego przykładem są stosunki między Polską i Uzbekistanem, a przejawem między innymi przekłady literatury. Autor zwraca uwagę, że przekład poezji wymaga od tłumacza dużej wiedzy ogólnej, powinien on także dysponować wiedzą w zakresie ogólnego kontekstu kulturowego.
Mixing in Extensional Flow Field
Authors: Utracki L. A. , Luciani A.
Published: May 2019

Mixing is the most important operation in polymer processing. Uniformity of the molecular weight, degree of entanglement, temperature, and composition, is the prerequisite for good performance. Mixing of molten polymers is always within the laminar (as opposed to turbulent) flow regime. This paper presents an overview of the effect of flow type on mixing. The distributive mixing is best modeled considering either laminar or chaotic mixing. Here the system is ”passive“, i.e.the rheological properties are identical and the interface is ”invisible“. Furthermore, the effects of flow and morphology are ”decoupled“. By contrast, the dispersive mixing is best modeled by means of microrheology, complemented by coalescence. Both models – the laminar mixing and the microrheology – show the unambiguous superiority of the extensional flows for dispersive and distributive mixing, in particular, when the viscosity ratio of two principal components is large. However this superiority is balanced by practical difficulties in generating a flow that may ascertain a high level of extension.

Results of simulation and model experiments on drop deformabilty in converging and diverging (c-d) flow were used to develop a simple and inexpensive mixer capable of generating a high level of extension that lead to enhanced mixing capability. In consequence, an extensional flow mixer (EFM) was designed. In this device, a liquid mixture is repeatedly exposed to extensional flow fields and semi-quiescent zones. The c-d channels are of progressively increasing intensity. To reduce the pressure drop, and to prevent blockage, slit restrictions are used. The EFM (as well as its newer, dynamic version – DEFM) is fully adjustable, general-purpose mixers. Several its versions have been used for: polymer blending, incorporation of elastomers into resins, and dispersion of high viscosity polymers or ”gel particles“. For most mixing applications a singe-screw extruder equipped with either EFM or DEFM performed at least as well as a co-rotating, inter-meshing twin-screw extruder, with high efficiency screw configuration.
The Erythrocyte Adhesiveness/Aggregation Test (EAAT) in the Peripheral Blood of Patients With Ischemic Heart and Brain Disease with Normal Fibrinogen Concentrations
Authors: Zeltser D. , Rotstein R. , Rogowski O. , Fusman R. , Shapira I. , Prochorov V. , Bornstein N. M. , Roth A. , Keren G. , Avitzour D. , Arber N. , Eldor A. , Berliner S.
Published: May 2019

Previous studies have documented the presence of increased red blood cell aggregability in patients with ischemic heart and brain diseases. We adapted a simple slide technique and image analysis to reveal the state of erythrocyte adhesiveness/aggregation (EAA) in the peripheral blood of 206 such patients and in 174 controls. A significant (P<0.0001) correlation was noted between the EAA state and both fibrinogen concentrations and erythrocyte sedimentation rate in the whole cohort. Noteworthy was a highly significant increment in the EAA state in a subgroup of 49 patients who had normal fibrinogen concentrations when compared to matched healthy controls. This was also the case in 82 patients who had a normal erythrocyte sedimentation rate. Thus, the EAA assay appears to have the advantage of revealing the presence of acute phase response sticky proteins not detected by either the erythrocyte sedimentation rate or clottable fibrinogen in some patients with a documented ischemic vascular disease.
A Comparative Rheological Study of Lime/Molasses and Sucrose/Lime/Water Mixtures in the Presence of Additives
Authors: Pannetier Nathalie , Habas Jean-Pierre , François Jeanne
Published: May 2019

Molasses containing sucrose, pectins, water and alcohol interacts with lime to form homogeneous blends. Rheological studies indicate that they exhibit viscoelastic behaviours as entangled polymers. Elastic modulus in these blends is much higher than for sucrose/lime/water model system. This difference is attributed to the presence of polysaccharide and ethanol in molasses. To verify this hypothesis, a model system was investigated in the presence of pectin and ethanol. Both additives were found to enhance viscosity and elasticity. In the presence of pectins, the formation of interpenetrated networks takes place, where calcium interacts with sucrose and pectins. Ethanol may have an influence on the complexes’ stability.
Comparison of Measurement Techniques for Evaluating the Pressure Dependence of the Viscosity
Authors: Goubert Alain , Vermant Jan , Moldenaers Paula , Göttfert Axel , Ernst Benoît
Published: May 2019

The different methods that can be used for measuring the effect of a hydrostatic pressure on the viscosity of polymer melts are evaluated. A linear low-density polyethylene is chosen as test material, as it can be expected to have a small pressure dependency. Special attention is given to methods employing capillary rheometry, as these methods yield a range of shear rates and pressures that are typically encountered under polymer processing conditions. The accuracy of the different techniques is evaluated considering also the complexity of the experimental devices. First it is investigated to which extent standard capillary rheometry can be used to extract information about the pressure dependency of the viscosity. Secondly, it is shown how the accuracy can be greatly increased by the simple addition of a pressure chamber below the exit of the capillary, with a needle valve to regulate the back pressure. The results from this device are compared with those from a more robust method using a pressurized double piston rheometer and with literature data. The experimental values for the pressure coefficient of the viscosity will also be compared with those predicted from PVT data using Utracki's method.
Mechanisms of Magneto- and Electro-Rheology: Recent Progress and Unresolved Issues
Authors: See Howard
Published: May 2019

An electrorheological fluid (ERF) (magnetorheological fluid - MRF) is a particulate suspension which shows a dramatic increase in flow resistance upon application of an external electric (magnetic) field. In both systems, the fundamental physical process is believed to be that the field induces polarization of each particle with respect to the carrier material, and the resulting interparticle forces cause elongated aggregates of particles to form in the field direction. While recent years have witnessed the appearance of several applications using these tunable flow properties, optimal use of this technology is still hindered by our incomplete understanding of the underlying mechanisms. This paper surveys our current understanding of several of the key issues governing the rheological behavior of MRF and ERF, with particular focus on recent progress made in important areas such as the behavior under high fields, sedimentation, temperature dependence, effect of wall surface conditions, and advances made in developing practical modelling strategies.
Rheological Characterization of Body Lotions
Authors: Yao Ming Long , Patel Jayesh C.
Published: May 2019

This study is attempted to demonstrate the application of rheological measurements in characterization of cosmetics products. As part of this study, several rheological tests were carried out on three common, commercially available body lotions to analyze their complex properties. The tests described in this study were simple and predictive in which the viscoelastic properties were successfully related with the end-use performance properties such as applicability, processing behavior, temperature sensitivity and storage and thermal stability.
An examination of the use of rotational viscometers for the quality control of non-Newtonian liquid products in factories
Authors: Barnes Howard A.
Published: May 2019

A frequent task undertaken by quality-control personnel in typical consumer-goods factories is the measurement of the viscosity of liquid products. The problem often faced in this task is how to strike the correct balance between the complete rheological characterisation of the non-Newtonian properties of the liquid of interest – which requires expensive, sophisticated equipment and can be quite time-consuming – and the dictates of production pressures that demand, as near as possible, an instant decision, and one usually based on a single number. Here we consider the rheological issues that arise in such a debate, which is aimed at finding what adequate characterisation would require.

We will investigate the implications of liquids products being non-Newtonian for two of the most commonly encountered viscometers in factory quality laboratories, i.e. the simple ‘dip-in’ rotating spindle viscometer of the Brookfield type (with its different forms and many imitations) and the more sophisticated concentric-cylinder-type device typified by the Haake Rotovisco VT 550 range. Each is capable of giving a single-number answer for viscosity, but the implications of understanding this single number are different in each case, with the dip-in viscometer being in an infinite sea of liquid and the concentric-cylinder situation being narrow gap. We also investigate when the infinite sea of the ‘dip-in’ viscometer is effectively ‘infinite’ and when is a concentric-cylinder geometry really ‘narrow gap’? We will use the power-law model throughout our discussions.
Combined Method for Quantitative Characterisation of Fluid Flow
Authors: Ivanov Yatchko , Kavardjikov Vasil , Pashkuleva Dessislava
Published: May 2019

A method has been proposed for quantitative characterization of the flow behaviour of fluids, which is an important problem of applied rheology. Particle Image Velocimetry technique has been used for visualization and measurement of the velocity field. The rheometric study of the fluid is aimed at determining the character of the flow and its dynamic viscosity. It is shown that the experimental data obtained for the velocity field and the viscosity are necessary and sufficient for determining the shear stress field at each point of the flow bulk. The major part of the investigations are performed using a Newtonian fluid (epoxy resin), but some data for the non-Newtonian fluid (solution of xantan) are shown too. The flow is produced by gravity in a system of tubes (a barrel and a capillary) with different round crossections. The possibility of further improvement of the combined rheo-optical method is shown.
Stability of Cement Grout: Study of Sedimentation Phenomena
Authors: Gelade Pierre , Le Roy Robert , Boucenna Imane , Flaud Patrice
Published: May 2019

The grouts are suspensions containing cement used in the technique of prestressing by post-tension. Cement, from its chemical nature, protects the wire ropes (strands) from corrosion. To be able to play correctly this protective role, the grout must remain homogeneous and must entirely cover the strands. The lack of stability of the grouts, which results in packing or sedimentation, is a major problem. In this article, we try to correlate the rheological properties of the grout with its capacity to remain homogeneous. We show that an increase in the concentration of superplasticizer, a polymer solution, decreases the thixotropic behavior of the grout, but on the other hand, increases the effects of sedimentation. We explain this phenomenon by the modification of the structure of a three-dimensional network in relation to the interparticle interactions.
Rheological Interpretation of the Slump Test
Authors: Baudez Jean-Christophe , Chabot Frédéric , Coussot Philippe
Published: May 2019

We examine the validity of the slump test for predicting the yield stress of polymeric suspensions and mineral suspensions. First we propose a modification of this test: in order to make measurements on fluids with high yield stress (of the order of several hundreds of Pascal) we add a mass at the sample top. From detailed observations of the slump in time we show that, for polymeric suspensions (hair gel and sewage sludges), two critical stresses can be distinguished which almost exactly correspond to the two critical stresses (respectively corresponding to a regime change and to the asymptotic slump) observed in rheometry during creep tests. Thus the slump test appears as a practiceful and relevant means to determine the intrinsic properties of these fluids. For mineral suspensions it is shown that the flow abruptly stops after a short time, a behaviour in agreement with the results of rheometrical tests carried out by progressively decreasing the applied stress. In that case the slump also appears to significantly depend on the procedure and cannot be related to a single property of the material.
Data Variability in Rheological Measurement of Semi-Solid Foods: Effects of Loading Normal Force
Authors: Daniels Pearce Melissa J. , Bellmer Danielle D.
Published: May 2019

Previous studies involving rheological measurement of semi-solid foods have reported a large amount of data variability, but have focused little on understanding the cause of such variability. This project examined whether differences in normal force have an effect on the variability of rheological measurements. Experimental methods focused on error introduced during sample loading; specifically whether normal force application during loading influenced the storage (G’) and loss (G”) moduli of semi-solid and liquid foods. Samples were loaded to 5 or 20 N between the parallel plates of a TA-1000N rheometer and tested immediately. For all semi-solid products tested, normal force application during sample loading did significantly affect oscillatory parameters, with G’ and G” measurements increasing up to 50 % with greater normal force. However, loading normal force did not significantly influence the parameters measured for the liquid sample. This suggests that differences in normal force during loading could be a significant source of data variability during rheological measurement of semi-solid products.
Viscoelastic Behavior of Disperse Systems with Silicone Oil and Different Fillers
Authors: Hadjistamov Dimiter
Published: May 2019

The rheological behavior of model suspensions with the silicone oil M20000 and different concentrations of Cab-o-sil TS 720 resp. Durcal 5 are compared. The increase of the Cab-o-sil concentration changes the flow behavior of the suspension from shear-thinning, to pseudoplastic, and to plastic flow behavior. The first normal stress difference rises at the same time at certain shear rate. The disperse systems with Durcal 5 keep the structural viscous behavior of the silicone oil even with a filler concentration of 40.5 wt%. The dependence of the first normal stress difference on shear rate represents for suspensions with Durcal 5 only one straight line with a slope of n = 2. The normal stress has double the amount of the silicone oil M20000 at given shear rate and is independent of the used Durcal 5 concentration. It was established that suspensions with the silicone oil M20000 have a first normal stress difference that can, depending on the filler type, either increase (with Cab-o-sil TS 720) or decrease (with Durcal 5) at certain shear stress with increasing filler concentration. It is to be supposed that the decrease of the normal stress at a given shear stress, with increasing Durcal concentration, is a softening effect, caused by the filler.
Flow of Some Carboxymethylcellulose Solutions Through Abrupt Axisymmetric Contractions. Experimental Study and Modelling of Shear Thinning and Elongational Effects
Authors: Devienne René , Corvisier Philippe , Lyazid Abdel
Published: May 2019

The focus of this paper will be on the modelling and simulation of contraction flow, with marked aspect ratio β = 6, 9, 12. Two fluid families are considered: a glycerol Newtonian solution and carboxy-methyl-cellulose (CMC) solutions which present particular rheological properties. Their shear thinning character are modelled by a Cross formula over a large scale of shear rates. The elongational properties are taken via a simplified Ericksen model into account. Experimental velocity profiles are determined using the Laser Doppler Anemometry (L.D.A) technique. They are found to be in good agreement with numerical velocity profiles obtained using a finite volume method with extra source terms traducing the particular rheological behaviour proposed here. The simulations allow to determine the different values of an elongational parameter μ3. Then, some numerical results concerning the total energy losses are presented using the usual concept of the equivalent length.
Dynamic Master Curves of Polymer Modified Asphalt from Three Different Geometries
Authors: Polacco Giovanni , Vacin Otakar Josef , Biondi Dario , Stastna Jiri , Zanzotto Ludovit
Published: May 2019

Polymer modified asphalt is an highly temperature sensitive material. To obtain the master curves of dynamic material functions, for this material, it is necessary to perform the testing over the temperature interval from -30˚C to at least 90˚C. Since in this temperature range the polymer modified asphalt undergoes the transition from a glass-like to a Newtonian-like material, the benefit of using three testing geometries is studied here. The geometries used were: torsion bar (for the low temperatures), plate-plate (for the mid range temperatures) and bob and cup (for the high temperatures). The advantage of the combination of these three geometries is discussed. Stress and strain controlled rheometers were used to conduct all dynamic experiments. Master curves obtained by these geometries cover up to 20 decades of the reduced frequency.
Stagnation Flow Studies of Polymer Solutions in 2D System
Authors: Joshi Ketan , Wedgewood Lewis
Published: May 2019

Stagnation flow studies form a key research area in numerous applications dealt with industry. When a fluid approaches a solid boundary, it undergoes severe deceleration along the axis of impingement. We present the experimental findings of the effects of stagnation point on polymeric flow systems. While coating metal sheets or wires with a polymer melt, the metal sheet forms a moving plane on which a steady flow of the melt is maintained. Further in the process the polymer melt cools down and forms a coating. Stagnation region exists around the point where the polymer melt first touches the metal sheet. We try to simulate this situation except in our experiments the solid plane is not moving. The polymer solution flows down the inverted T-channel and strikes the base where we obtain the stagnation region. Laser Doppler technique is used to analyze the flow profile in this region. Initial analysis includes the analysis of a Newtonian fluid which is compared to theoretical predictions. Polyisobutadiene solution with three different concentrations, 0.1%, 1% and 3%, was tested for observing the effect of the change in concentration on the flow patterns around the stagnation point. In the stagnation region the fluid is not completely stagnant but follows a non-streamwise motion.
Using Self-Sensing Techniques to Produce a Small, Robust, Inexpensive Rheometer
Authors: Hanson Ben , Levesley Martin , Fisher John
Published: May 2019

Self-sensing is the technique of using a transducer to both actuate and sense concurrently, therefore eliminating the need for separate sensors. A sensorless rheometer could be much smaller, simpler and more robust than traditional designs. One application where such a rheometer would be desired is the in-situ measurement of curing bone cement in orthopaedic surgery. A set of equations was developed that models the relationship between force, motion and back-e.m.f. generation for a class of electromagnetic actuators. This enables velocity, displacement and force to be self-sensed from voltage measurements only. This self-sensing was validated on a conventional linear electromagnetic actuator, and a small rotary moving magnet device, which was designed to be a small self-sensing rheometer. The accuracy of the estimation was assessed and shown to compare favourably with measured data. The actuators were then used to construct simple rheometers to measure bone cement. Rheological models were used to calculate storage and loss moduli and dynamic viscosity from the self-sensed values of displacement, velocity and torque. The accuracy of these self-sensing rheometers was verified against a traditional rheometer using a silicone fluid and a polyethylene oxide solution. The self-sensing rheometers were used to characterise acrylic bone cements during curing, reinforcing and extending upon previous results. The elimination of sensors meant that it was possible to produce a small, inexpensive rheometer with a very simple structure. This indicates there is potential to develop small rheo-transducers for certain applications.
Sol – Gel Modelling Associated with the Rheology of Polymeric Precursors of Ceramic Materials
Authors: Balan Corneliu , Riedel Ralf
Published: May 2019

A general constitutive relation describing the change of viscoelastic behavior during the liquid - solid (sol - gel) transition which takes place in preceramic polymers is derived on the basis of Jeffrey’s 3-constants model with time dependent viscosities and elasticity. It is postulated that the sol - gel - transition can be analyzed analogous to the solutions of the Avrami equation used for modeling crystallization processes. Two different polymer systems used as precursor for the production of ceramic materials are investigated here: i) a mixture based on polysiloxane, alumatrane and isopropanol; ii) a non-oxidic carbodiimide gel based on the reaction of chlorosi-lanes with bis(trimethylsilyl)carbodiimide. Continuous measurements of the dynamic moduli versus reaction time, as well as creep tests at constant shear stress, evidenced both qualitative similarities and quantitative differences associated with the sol - gel transition of the two polymer systems. The shear rate and viscosity dependence of reaction time in creep tests, respectively the evolution of Lissajous figures associated with oscillatory experiments, are found to be consistent with the numerical simulations of the proposed constitutive relation.
Influence of Cluster Formation: Viscosity of Concentrated Emulsions
Authors: Kyazze G. , Starov V.
Published: May 2019

Recently a new theory of viscosity of concentrated emulsions dependency on volume fraction of droplets (Starov V, Zhdanov G: J. Colloid Interface Sci, 258, 404 (2003)) has been suggested that relates the viscosity of concentrated emulsions to formation of clusters. Through experiments with milk at different concentrations of fat, cluster formation has been validated using optical microscopy and their properties determined using the mentioned theory. Viscometric studies have shown that within the shear rate range studied, both the packing density of fat droplets inside clusters and the relative viscosity of milk (viscosity over skim milk viscosity) are independent of shear-rate, but vary with volume fraction. Comparison of the experimental data with previous theories that assumed that the particles remained discrete shows wide variation. We attribute the discrepancy to cluster formation.
Use of Quadratic Model for Modelling of Fly Ash-Water Mixture
Authors: Marn Jure , Ternik Primož
Published: May 2019

Novel approach to rheological modelling of a fly ash-water mixture is proposed. The model is first tested against the available experimental data for a corn starch-water, a glass beads-water and a fly ash-water mixture and then used taking the advantage of available CFD code for a calculation of major and minor losses. Numerical results for Quadratic model are compared with results for Power law.
Rheology and Storage Tests of Dead Sea Shampoo
Authors: Abu-Jdayil Basim , Mohameed Hazim , Snobar Tamara , Sa’id Maha
Published: May 2019

Changes in the rheological properties of hair shampoo samples differing in the content of Dead Sea (DS) salt were studied. The rheological properties were tested during a 28-day storage period at three different storage temperatures (cold, room temperature and accelerated conditions). Steady rheological tests were performed and the conductivities of the shampoo samples were determined. The parameters of the power law model; the consistency coefficient and the flow behavior index were used to quantify the effect of storage time and temperature on the rheological behavior of hair shampoo in the presence of DS salt. The consistency coefficient of the salt free shampoo samples stored at 8°C and at room temperature decreased with storage time, and the rheological behavior changed from shear thinning to Newtonian. On the other hand, the samples stored at 45°C exhibited a shear thinning behavior, which did not change with storage time. Shampoo samples with 1.5 wt% DS salt content, showed the maximum viscosity and the rheological behavior of the samples did not change with the storage time. An exception were the samples stored at 45°C, which behaved like the salt free samples stored at room temperature. The conductivity of hair shampoo increased linearly with storage time and salt concentration. A discontinuity at a salt concentration of 1.5% was observed. However, the conductivity of hair shampoo increased with increasing the storage temperature.
Temperature Behavior of Magnetorheological Fluids
Authors: Zschunke F. , Rivas R. , Brunn P.O.
Published: May 2019

Magnetorheological fluids (MRFs) show a high but reversible rise of the viscosity upon application of an external magnetic field. This effect can be utilized in controllable friction dampers where the MR fluid flows through a gap with a adjustable magnetic field. The change in the magnitude of the magnetic field leads to a change of the viscosity of the fluid which in turn effects the pressure drop in the system. So the damping force can be controlled by the magnitude of the external magnetic field. This energy dissipation leads to a rise of the damper temperature. For designing those dampers it is vital to know the influence of the geometry, which influences the magnetic field strength, as well as the flow properties and the temperature dependence of the magnetorheological effect. An approach to the solution of this problem is shown by using an Arrhenius relationship, where the fluid viscosity is a function of the shear rate, the magnetic field and the temperature. The aim of the here presented research is to show how the fluid behavior can be simply modeled for use in CFD codes to design dampers or other applications.
Bostwick Degree and Rheological Properties: an Up-to-date Viewpoint
Authors: Perona Paolo
Published: May 2019

The correlation between the Bostwick degree and the static rheological properties of yield stress food fuids is first revisited and then reformulated in this work. The role of the yield stress in the free surface flow of the Bost-wick test is studied using dimensional analysis. Results from experiments on 48 different samples of yield stress fluids are considered and included to check the adequacy of the proposed correlation. Asymptotic dynamic behaviour is also presented and discussed as a mechanism of complete self similarity with respect of the dimensionless time. This approach would seem to support the opinions in favor of the yield stress as a key parameter, and thus offers an interesting new viewpoint useful to both future experiments on the Bostwick test and studies of 'dam-break' like dynamics.