bluuebunny/crossref_metadata_2025_split huggingface dataset:
The guanidinium t-diaqua-bis(oxalato)chromate(III) dihydrate complex: synthesis, crystal structure, EPR spectroscopy and magnetic properties
Authors: Kamga Idelle Nono , Nana Augustin Nkwento , Ndosiri Bridget Ndoye , Capet Frédéric , Foulon Michel , Nenwa Justin 
Published: March 2021

Abstract
A new salt (CH6N3)[t-Cr(C2O4)2(H2O)2]·2H2O (1) (CH6N3
+ = guanidinium cation) has been synthesized and characterized by single-crystal X-ray diffraction, FT-IR and UV–Vis spectroscopies, elemental and thermogravimetric analyses. In the crystal structure of 1, the chromate(III) ion lies on an inversion center in the form of an elongated octahedron. The coordination sphere consists of four oxygen atoms of two chelating oxalato ligands in the equatorial plane and two axial oxygen atoms of water ligands. The structural feature of focal interest in the structure of 1 is the formation of pillars of [Cr(C2O4)2(H2O)2]− complex anions and CH6N3
+ guanidinium cations, with the next-neighbor cations rotated by an angle of 60° relative to each other. O–H···O and N–H···O hydrogen bonds play an important role in the construction of the three-dimensional network. The electron paramagnetic resonance (EPR) and magnetic properties of 1 have also been investigated.
Synthesis of the scandium chloride hydrates ScCl3·3H2O and Sc2Cl4(OH)2·12H2O and their characterisation by X-ray diffraction, 45Sc NMR spectroscopy and DFT calculations
Authors: Bräuniger Thomas , Bielec Philipp , Zeman Otto E. O. , Moudrakovski Igor L. , Hoch Constantin , Schnick Wolfgang 
Published: March 2021

Abstract
The compounds ScCl3·3H2O (SCTH) and [{Sc(H2O)5(μ-OH)}2]Cl4·2H2O (SCOH), have been synthesised and characterised by single-crystal XRD, 45Sc NMR spectroscopy and DFT calculations, with the crystal structure of SCTH reported here for the first time. From 45Sc NMR measurements under static and MAS conditions, both chemical shift and quadrupolar coupling parameters have been determined. The quadrupolar coupling constants χ for the octahedrally coordinated scandium sites in SCTH are 2.0 ± 0.1 MHz for Sc(1) and 3.81 ± 0.05 MHz for Sc(2). For SCOH, where the hepta-coordination of the single scandium site constitutes a less symmetric electronic environment, 14.68 ± 0.05 MHz was found. DFT calculations for the static SCTH structure consistently overestimate the quadrupolar coupling constants, indicating the possible presence of crystal water dynamics on the NMR time scale.
An investigation on the performance and emission studies on diesel engine by addition of nanoparticles and antioxidants as additives in biodiesel blends
Authors: Reddy Siddavatam Naresh Kumar , Wani Mohmad Marouf 
Published: March 2021

AbstractThe study aims to examine the effects of palm biodiesel blended with additives in the compression ignition (CI) engine. Biodiesel as fuel was limited by challenges such as lower calorific value (CV) and higher viscosity while increasing brake specific fuel consumption (BSFC) and nitrogen oxides (NOx) emissions. Nanoparticles and antioxidant additives added to biodiesel play an essential role in avoiding the hindrances of biodiesel. The antioxidants combined with biodiesel reduced NOx emissions by eliminating decomposing peroxides, free radicals, and preventing free radicals' chain reaction. The Significant characteristics of nanoparticles are high CV, high thermal conductivity, and higher surface to volume ratio. These characteristics are used to improve the CI engine's performance and emissions by using nanoparticles blended with biodiesel. Five different test blends of Diesel, B20, B20TO, B20AO, and B20AOTO were prepared. The result showed high brake thermal efficiency (BTHE) and decreased BSFC, exhaust gas temperature (EGT), hydrocarbons (HC), NOx, and HC emissions by using the B20AOTO fuel blend contrasted with other biodiesel blends.
Notas sobre gênero em O Capital de Marx
Authors: Federici Silvia 
Published: March 2021

Silvia Federici propõe-se a resgatar as análises de Marx a respeito de gênero e trabalho em O Capital, fazendo uma avaliação da ambiguidade da contribuição de Marx. Segundo a autora, por um lado, Marx avaliou criticamente as relações entre o desenvolvimento do capitalismo e a exploração do trabalho operário feminino no período de surgimento da industrialização. Além disso, a autora identifica na crítica do trabalho no capitalismo uma referência importante para a formação da crítica feminista. Por outro lado, Federici mostra os diversos limites da abordagem de O Capital a respeito do problema do gênero. Dentre os tópicos apontados, destacam-se: (1) a ausência de uma abordagem analítica, e não apenas meramente descritiva, dacondição da mulher nas fábricas; (2) a omissão do papel do trabalho reprodutivo como um pilar do modo de produção capitalista; (3) a crítica à leitura de Marx que via no capitalismo um caminho necessário para criação das condições de emancipação da mulher; (4) e, por último, a crítica à tese de Marx de que no capitalismo só o trabalho industrial lançaria os fundamentos normativos para a organização do trabalho.Contrariamente a Marx, Federici sustenta que também a dicotomia produtivo-reprodutivo é determinada historicamente pelo modo de produção capitalista, sem a qual a acumulação capitalista não poderia existir. Por fi m, a autora conclui que esses erros e omissões teóricas não são casuais, mas fruto de pontos de vista teóricos e políticos de Marx, que não encontrava respaldo numa refl exão acurada sobre os vínculos entre gênero e capitalismo.
Do universal ao específco
Authors: Motta Daniele 
Published: March 2021

A presente carta dialoga com algumas ideias de Karl Marx e do marxismo para fazer alguns questionamentos referentes às perspectivas de gênero e de raça. A partir da experiência pessoal da autora, de uma leitura da formação social brasileira e de uma leitura terceiro-mundista, a argumentação traz esses questionamentos no intuito de contribuir para a formação de uma perspectiva analítica da imbricação de gênero, raça e classe que leve em consideração o método histórico de Marx e suas contribuições para a compreensão da sociedade capitalista. Dessa forma, a intenção da carta é levantar também aspectos das especifcidades do desenvolvimento do capitalismo no Brasil, com base em uma leitura interseccional constituída no âmbito das perspectivas metodológicas presentes na teoria feminista contemporânea e, com isso, traçar um diálogo com Marx, reﬂetindo de que maneira suas contribuições ainda hoje são relevantes para a análise das relações sociais.
A economia política hoje (e outros assuntos)
Authors: Paulani Leda 
Published: March 2021

A presente carta inicia com algumas problematizações dos fundamentos flosófcos mais contemporâneos à luz da perspectiva crítica do materialismo marxiano para passar às considerações sobre a emergência e o desenvolvimento da chamada “revolução marginalista” no âmbito econômico, da teoria keynesiana e, posteriormente, da chamada teoria das expectativas racionais, levantando os problemas de cada uma delas a partir da perspectiva marxista.
Marx para além da grande-indústria
Authors: Romero Daniel 
Published: March 2021

As profundas transformações atuais no mundo do trabalho têm sugerido a superaçãodo capitalismo de tipo industrial para formas sociais de produção mais baseadasno uso da informação, no trabalho imaterial e na relação entre ciência e processode produção. Tais transformações, inclusive, serviram de suporte para a idéia de queestaríamos rumo a sociedades de tipo “pós-industrial”.Para alguns estudiosos, é como se estivéssemos diante não apenas de mutaçõesfenomênicas e particulares, mas da reconfiguração das próprias bases da sociedadeatual2 . Nos casos mais extremos, estas mudanças indicariam a formação de um novoprojeto civilizacional e a exigência de uma radical mudança epistemológica visando aconstrução de uma nova teoria dos conflitos3 . Como ressalta Mandel, “a presente crisenão é vista como uma crise típica de superprodução e superacumulação, mas como uma crise de civilização”4 . Este também é o caso de teóricos que tematizam o “fim dasociedade do trabalho”5 .A presente pesquisa visa poder contribuir para este extenso debate em torno dastransformações atuais no mundo do trabalho e acreditamos que isto pode ser feitopelo retorno à “letra” de Marx. Esta comunicação se propõe a discutir a relação entreciência e processo de produção nos Grundrisse de Karl Marx. A nossa proposta principalé ler a teoria da transição de Marx presente na referida obra como uma possívelindicação de uma teoria da pós-grande indústria (nos termos de Ruy Fausto6 ) aindanos marcos do modo de produção capitalista. Ou seja, como uma terceira formasocial de produção capitalista, para além da manufatura e da grande indústria.Nesta obra, o autor aborda questões que acreditamos ser de extrema pertinênciapara a análise do processo de produção, como a interação entre trabalho e saber científico.A partir disto, esta comunicação é um esforço inicial de precisar e atualizaralguns conceitos como o de divisão do trabalho e subsunção, o que permitiria avançarnuma teoria capitalista da pós-grande indústria.
Big Data Analytics in E-commerce for the U.S. and China Through Literature Reviewing
Authors: Zhuang Weiqing , Wang Morgan C. , Nakamoto Ichiro , Jiang Ming 
Published: March 2021

AbstractBig data analytics (BDA) in e-commerce, which is an emerging field that started in 2006, deeply affects the development of global e-commerce, especially its layout and performance in the U.S. and China. This paper seeks to examine the relative influence of theoretical research of BDA in e-commerce to explain the differences between the U.S. and China by adopting a statistical analysis method on the basis of samples collected from two main literature databases, Web of Science and CNKI, aimed at the U.S. and China. The results of this study help clarify doubts regarding the development of China’s e-commerce, which exceeds that of the U.S. today, in view of the theoretical comparison of BDA in e-commerce between them.
Morphological and molecular characterisation of Longidorus pauli (Nematoda: Longidoridae), first report from Greece
Authors: Tzortzakakis Emmanuel A. , Clavero-Camacho Ilenia , Cantalapiedra-Navarrete Carolina , Ralli Parthenopi , Palomares-Rius Juan E. , Castillo Pablo , Archidona-Yuste Antonio 
Published: March 2021

Abstract
Sampling for needle nematodes was carried out in a grapevine area in Thessaloniki, North Greece and two nematode species of Longidorus (L. pauli and L. pisi) were collected. Nematodes were extracted from 500 cm3 of soil by modified sieving and decanting method, processed to glycerol and mounted on permanent slides, and subsequently identified morphologically and molecularly. Nematode DNA was extracted from single individuals and PCR assays were conducted to amplify D2-D3 expansion segments of 28S rRNA, ITS1 rRNA, and partial mitochondrial coxI regions. Morphology and morphometry data obtained from these populations were consistent with L. pauli and L. pisi identifications. To our knowledge, this is the first report of L. pauli for Greece, and the second world report after the original description from Idleb, Syria, extending the geographical distribution of this species in the Mediterranean Basin.
El sujeto del discurso científico
Authors: García Molina Bartolo 
Published: March 2021

En este ensayo procuro demostrar que las fuentes de la subjetividad no están en las marcas que inevitablemente plasme el investigador científico en su discurso, sino en el rigor y claridad del mismo. Defiendo que una dosis de subjetividad en algunas etapas del proceso de producción científica no solo es saludable, sino inevitable, por lo que no tiene fundamentación científica la cancelación del sujeto de la investigación y la prescripción absoluta de su eventual aparición como sujeto gramatical de algunos enunciados. Señalo como fuente de subjetividad perniciosa la autorreferencialidad, la modalización, el sesgo de confirmación, la ponderación subjetiva, las expresiones sin fundamentos empíricos, los prejuicios y adjetivos y los adverbios de cuantificación o ponderación. Mis reflexiones tienen como base metodológica y sustentación teórica el análisis crítico del discurso y la filosofía de la ciencia.
Pengetahuan dan Sistem Pengelolaan Pertambangan Minyak Rakyat di Gampong Alue Dua Aceh Timur
Authors: Fitriani  , Ade Ikhsan Kamil  
Published: March 2021

This article discusses the knowledge of community oil miners in the People's Mining in Alue Dua Village, Rantau Peureulak District, East Aceh Regency. The author collects data using participatory observation, in-depth interviews and corroborates it by studying literature. The results showed that the knowledge of miners in Gampong Alue Dua was formed along with the history of the emergence of mining in Peureulak, especially when the oil companies entered to take samples of land as proof that the Peureulak area has the potential to contain oil, and also because of self-taught learning. For miners, there are 4 special signs in identifying land that has the potential to contain oil: 1) the land selected for drilling that is close to and is still in the same lane as the Dutch heritage lake. 2) The distance between the land which is the drilling position and the Dutch heritage lake is about 100-150 meters. 3) Selection of old wells or Dutch heritage ponds with the category of no longer active. 4) Get back to the miners' technicians at work.
Abstrak
Artikel ini membahas tentang pengetahuan penambang minyak rakyat yang ada di Pertambangan Rakyat di Gampong Alue Dua, Kecamatan Rantau Peureulak, Kabupaten Aceh Timur. Penulis mengumpulkan data dengan cara observasi partisipasi, wawancara mendalam dan menguatkannya dengan studi literatur. Hasil penelitian menunjukkan bahwa pengetahuan penambang di Gampong Alue Dua terbentuk seiring sejarah kemunculan pertambangan di Peureulak, terutama saat masuknya perusahaan minyak untuk mengambil sempel tanah sebagai pembuktian bahwa daerah Peureulak berpotensial mengandung minyak, dan juga karena faktor belajar secara otodidak. Bagi para penambang, terdapat 4 tanda khusus dalam mengenali lahan yang berpotensial mengandung minyak: 1) lahan yang dipilih untuk melakukan pengeboran adalah lahan yang dekat dan masih satu jalur dengan telaga peninggalan Belanda. 2) Jarak lahan yang menjadi posisi pengeboran dengan telaga peninggalan Belanda sekitar 100-150 meter. 3) Pemilihan sumur tua atau telaga peninggalan Belanda dengan kategori sudah tidak aktif lagi. 4) Kembali pada teknisi para penambang dalam bekerja.
Awareness about wear and care of contact lenses among undergraduate medical students
Authors: Lathishna A. G  , Xavier Jayaseelan C  
Published: March 2021

This study aims to assess among the undergraduate medical students the knowledge about wear and care of contact lens and also to highlight their awareness about complications of inappropriate contact lens use. A pretested semi-structured questionnaire conducted the study. Fifty students were selected from each year to come up with a sample size of a total of 200 undergraduate medical students. Questions about the use of contact lens, hygienic practices in contact lens use and also complications related to contact lens usage were asked in the questionnaire. Out of 200 students surveyed, only 31 participants were wearing contact lens. It was observed that in our study, 54.84% of students were using contact lens for refractive error, 29.03% for cosmetic purpose and 16.13% for convenience. 66.5% of students did not know about overwear syndrome.36.5% of students were aware that Pseudomonas is most commonly involved in contact lens-related ulcers. 73.79% spectacle users stated that they are convenient with spectacles preferably than a contact lens. About 53% of students gained knowledge about contact lens through friends and family. A good number of students were aware of most of the hygienic practices of contact lens and complications related to contact lens wear. However, education about do's and don'ts regarding contact lens should also be taught to medical students during Ophthalmology postings to make them aware of complications of contact lens usage.
Neuroprotective activity of Garcinia morella desr against monosodium glutamate-induced neurotoxicity in rats
Authors: Iyappan R  , Neeraj K Sharma  , Senthilkumar S K  
Published: March 2021

The aim of the present study is to evaluate the neuroprotective effect of methanol extract of Garcinia morella Desr leaves in monosodium glutamate (MSG) induced neurotoxicity in rats. The MSG 2 g/kg, i.p. was used to induce the neurotoxicity. The rats were administrated with methanol extract of Garcinia morella Desr leaves (MEGM) 200 and 400 mg/kg, p.o. and Dextromethorphan 30 mg/kg, p.o. after 1 h injection of MSG. The animals were evaluated for its behavioural factors such as muscle grip and locomotor activity. At the end of the study, the antioxidant enzymes levels, neurotransmitter levels, TNFα, ß-amyloid and mineral levels were estimated in brain homogenate. The MEGM treated group shows significant improvement of behavioural and locomotor activity and muscle strength against MSG induced neurotoxicity. The glutathione, SOD, catalase and total protein levels were significantly increased in MEGM treated group. However, significant reduction within the level of varied neurotransmitters like AChE, Dopamine, TNFα, ß-amyloid were observed on treatment with MEGM extract. Further, MEGM also significantly decrease the MSG induced toxicity through declined levels of Ca+2 and Na+ with increased levels of K+. In conclusion, the present study suggests that the MEGM has significant neuroprotective activity against MSG induced neurotoxic rats.
SIFAT FISIK DAN MEKANIK PAPAN PARTIKEL AKIBAT PENAMBAHAN FILLER SERAT BAMBU
Authors: Rofaida Aryani , Pratama Rizki Mikroji , Sugiartha I Wayan , Widianty Desi 
Published: March 2021

Bambu adalah salah satu sumber daya alam yang mudah diperoleh dan diperbaharui, sehingga menjadi alternatif pengganti untuk pembuatan papan partikel kayu. Studi ini mengelaborasi sifat fisik maupun mekanik papan partikel kayu yang diperoleh secara eksperimen kemudian dibandingkan dengan ketentuan yang terdapat dalam Standar SNI 03-2105-2006. Ukuran papan partikel yang akan diuji sesuai dengan standar SNI 03-2105-2006, Pengujian yang dilakukan yaitu pengujian sifat fisik dan mekanik meliputi : uji kerapatan, kadar air, daya serap air, pengembangan tebal setelah direndam air, Modulus of Rupture (MOR), Modulus of Elasticity (MOE), keteguhan rekat, dan keteguhan cabut sekrup.Tujuannya adalah untuk mengetahui perilaku fisik dan mekanik papan partikel akibat adanya penambahan filler serat bambu. Hasil pengujian pengembangan tebal papan partikel menunjukkan bahwa pengembangan tebal papan partikel dengan penambahan filler serat bambu mempunyai nilai pengembangan tebal terendah yaitu 4,504 %. Berdasarkan standar SNI 03-2015-2006 nilai pengembangan tebal yaitu ≤ 12 %. Sedangkan nilai sifat mekanik dengan rata-rata nilai MOR adalah 95.395 MPa, nilai MOE adalah 68,7996 MPa,nilai keteguhan rekat adalah 48,38 MPa, dan uji kuat tarik sekrup 1105,25 N.
Studi mechanical properties dan struktur mikro hasil variasi temperatur dan waktu aging pada alumunium matrix composite (AMC) hasil proses stir casting dengan kandungan matrix Berlebih
Authors: Saefuloh Iman 
Published: March 2021

Alumunium matrix composite (AMC) banyak digunakan sebagai bahan di banyak bidang (otomotif, pertambangan, penerbangan, pertahanan) karena ringan, dipilih sebagai material ini ringan dan relatif murah dan mudah difabrikasi. Proses pembuatan AMC tidak mudah karena matrik dapat membentuk gumpalan. Proses Stir casting dipilih dalam proses ini karena dapat menghasilkan AMC lebih merata dan dapat memecah gumpalan tersebut. Setelah stir casting dilakukan proses perlakuan panas aging agar material hasil lebih baik. Penelitian ini bertujuan menggunakan alumunium sebagai matrik dan senyawa karbida SiC sebagai penguat dengan proses aging suhu 1000C dan 2000C dengan waktu penahanan selama 1, 2, 3 dan 4 jam untuk meningkatkan mechanical properties dan memperbaiki struktur mikro. Setelah melalui proses pengujian didapatkan waktu aging berpengaruh terhadap mechanical properties yang di hasilkan, semakin lama waktu aging semakin besar pula kenaikan mechanical properties, untuk nilai kekuatan tarik naik sampai 70% dan kekerasan naik sampai 31%.
Penambahan Water Coolant Pada Cooling Tower Tipe Counter Flow
Authors: Zulfikar Zulfikar 
Published: March 2021

Cooling tower adalah alat penukar kalor dengan fluida kerja air dan udara yang berfungsi mendinginkan air dengan kontak langsung dengan udara yang mengakibatkan sebagian kecil air menguap. Dalam kebanyakan cooling tower yang bekerja pada sistem pendinginan udara menggunakan pompa sentrifugal untuk menggerakkan air vertikal ke atas melintasi menara. Semua cooling tower yang bekerja akan melepaskan kalor melalui kondensor, refrigeran akan melepas kalornya kepada cooling tower sehingga air menjadi panas. Selanjutnya air panas ini akan dipompakan ke cooling tower. Dalam Penelitian ini peneliti akan menambahkan coolant yang kita tahu berfungsi sebagai pendingin. Tujuan penelitian ini adalah untuk mengetahui pengaruh penambahan water collant terhadap efektifitas pendinginan cooling tower. Penelitian terdahulu yang sudah pernah dilakukan adalah meneliti kinerja cooling tower dan efektifitas pendinginan cooling tower tersebut. Hasil penelitian diperoleh suhu awal air yang masuk ke cooling tower adalah 50 ᵒC dan suhu air setelah diproses di colling tower tersebut adalah 40 ᵒC untuk water coolant merk A, sedangkan untuk water coolant merk B adalah 38 ᵒC . Dengan hasil ini dapat diketahui bahwa dengan penambahan coolant terhadap kinerja colling tower mempengaruhi efektivitas pendinginan cooling tower tersebut.
Perbandingan Konsumsi Bahan Bakar Minyak Hasil Pirolisis Plastik HDPE Bercampur Serabut Kelapa Terhadap Premium
Authors: Alfiando Diego Alfin , Setyowidodo Irwan , Nuryosuwito Nuryosuwito 
Published: March 2021

Salah satu alternative penanganan sampah plastik yang saat ini banyak diteliti dan dikembangkan adalah mengubah sampah plastik menjadi bahan bakara lternatif dan serabut kelapa telah di gunakan sebagai bahan bakar untuk menghasilkan energi mekanik dan panas. Kandungan silika ( S_iO₂ ) pada abu serabut kelapa yang tinggi yang dapat di gunakan sebagai sumber alternatif. Tujuan penelitian ini adalah untuk memperoleh bahan bakar cair dari pirolisis sampah plastik, dengan nilai kalor dan mutu bahan bakar minyak yang baik. Metode yang digunakan adalah Plastik yang pada dasarnya terbuat dari minyak bumi akan dikembalikan lagi ke bentuk asalnya dengan cara menggunakan proses pirolisis. Pirolisis atau devolatilisasi adalah proses fraksinasi material oleh suhu. Dengan pengujian konsumsi bahan bakar didapat hasil nilai konsumsi plastik HDPE yang terkecil sebesar 4 ml mengunakan Rpm 2000 dengan selang waktu 2 menit sedangkan nilai premium yang terkecil sebesar 10 ml dengan Rpm dan waktu yang sama kerena nilai oktan sebesar 97 yang hampir sama dengan nilai oktan Pertamax turbo.
Rancang Bangun Mesin Pencetak Pellet dari Limbah Telur Solusi Pakan Ternak Alternatif
Authors: Nugroho Setiya , Setyowidodo Irwan , Istiqlaliyah Hesti 
Published: March 2021

Perancangan ini dilatar belakangi hasil observasi dan studi literatur, tepatnya didaerah Kalidawir limbah penetasan telur bebek cukup besar. Hampir setiap hari limbah tersebut ada, akan tetapi masih belum banyak dimanfaatkan secara optimal oleh peternak maupun masyarakat sekitar. Khususnya sebagai pakan ternak alternatif, karena belum adanya penggunaan mesin pencetak pelet dari bahan limbah telur penetasan bebek. Biasanya mesin ini hanya digunakan dalam pencetakan pelet dari bahan dedak halus dan frementasi yang telah dirancang khusus untuk membuat pakan ternak. Perancangan ini dilakukan untuk untuk memebuat alat pencetak pellet dari limbah telur bebek beserta menghitung kapasitas produksinya. Hasil perancangan menggunakan motor listrik 1400 rpm, gear box 1:60, tanki conveyor dengan panjang 220 mm, die dengan ukuran 2 dan 4 mm dan tebal 8 mm, pisau pemotong dengan tebal 1 mm, panjang 35 mm dengan kecepatan 9 rpm dan menghasiilkan kapasitas 15 kg/jam.