bluuebunny/crossref_metadata_2025 huggingface dataset:
STUDI PENENTUAN STATUS MUTU AIR SUNGAI KUALA DUA UNTUK KEPERLUAN BAHAN BAKU AIR BERSIH
Authors: Sisuanto Donatus Franky
Published: July 2019

ABSTRAK   Sungai Kuala Dua merupakan bagian dari sub DAS Kapuas yang aliran airnya bermuara pada Sungai Kapuas Kecil dan letak hulu Sungai Kuala Dua yang berada dan berhubungan langsung dengan Sungai Kapuas Besar. Keberadaan pemukiman penduduk yang padat di wilayah aliran Sungai Kuala Dua sangat mempengaruhi kualitas air, seperti aktifitas buangan domestik yang berasal dari rumah tangga. Keberadaan salon, bengkel, rumah makan, dan Pasar Kuala Dua yang belum memiliki IPAL di bantaran Sungai Kuala Dua juga semakin menambah sumber beban pencemar yang masuk ke Sungai Kuala Dua. Hal tersebut menjadi dasar peneltian ini, yaitu untuk menentukan status mutu air Sungai Kuala Dua yang digunakan sebagai keperluan bahan baku air bersih oleh warga sekitar dan memberikan rekomendasi untuk Sungai Kuala Dua yang dilihat dari status mutu air Sungai Kuala Dua. Metode yang digunakan untuk mengidentifikasi kualitas air dengan melakukan uji terhadap parameter-parameter pencemaran air yang dibandingkan dengan baku mutu air kelas II PP No. 82/2001 tentang Pengelolaan Kualitas Air dan Pengendalian Pencemaran Air yang meliputi parameter fisik (suhu dan TSS); parameter kimia (pH, BOD, dan Minyak dan Lemak); dan parameter mikrobiologi (Total Koliform). Penentuan status mutu air dengan menggunakan metode indeks pencemaran yang dibandingkan dengan baku mutu air kelas II PP No. 82/2001, dimana metode ini terlampir dalam Kepmen LH No. 115/2003 tentang Pedoman Penentuan Status Mutu Air. Penentuan lokasi pengambilan sampel dibagi menjadi 4 lokasi yaitu hulu Sungai Kuala Dua, pemukiman, pasar, dan hilir Sungai Kuala Dua saat kondisi pasang dan surut pada bulan Januari 2017. Kondisi Kualitas air Sungai Kuala Dua berdasarkan uji parameter pencemaran air menunjukkan parameter pH, BOD, dan Total Koliform yang melebihi baku mutu kelas II di semua lokasi pengambilan sampel pada saat kondisi pasang dan surut. Analisis Indeks Pencemaran Sungai Kuala Dua menunjukkan saat kondisi pasang nilai Indeks Pencemaran 4,09 (hulu sungai), 4,22 (pemukiman), 4,25 (pasar), 1,97 (hilir sungai). Saat kondisi surut nilai Indeks Pencemaran 4,22 (hulu sungai), 4,52 (pemukiman), 4,44 (pasar), 3,62 (hilir sungai). Berdasarkan analisis tersebut dapat disimpulkan status mutu air Sungai Kuala Dua dalam kondisi cemar ringan pada semua lokasi pengambilan sampel saat kondisi pasang dan surut, yang ditunjukkan dengan nilai Indeks Pencemaran 1,1 – 5,0 merupakan mutu perairan yang memiliki status kondisi cemar ringan (Kepmen LH No. 115 tahun 2003). Rekomendasi yang diberikan untuk pengendalian pencemaran air Sungai Kuala Dua adalah melakukan inventarisasi dan identifikasi sumber pencemaran air, meningkatkan pengelolaan limbah, dan meningkatkan pemantauan kualitas air Sungai Kuala Dua.   Kata kunci: Sungai Kuala Dua, Status Mutu Air, Indeks Pencemaran
ANALISIS KUALITAS AIR DANAU KANDUNG SULI KECAMATAN JONGKONG KABUPATEN KAPUAS HULU
Authors: Kiki Priyo Utomo Lailial Nurhayati
Published: July 2019

ABSTRAKDanau Kandung Suli merupakan sumber air utama bagi penduduk yang dimanfaatkan langsung untuk keperluan domestik seperti mandi dan mencuci, juga untuk budidaya ikan menggunakan keramba. Kegiatan domestik dan budidaya ikan di perairan Danau Kandung Suli akan mengakibatkan penurunan kualitas air. Kualitas air Danau Kandung Suli dalam penelitian ini diuji dengan metode Indeks Pencemaran (IP) dan disesuaikan dengan baku mutu PP No. 82/2001. Tahapan penelitian meliputi pengukuran kedalaman air, pengambilan sampel air, uji kualitas air dan analisis indeks pencemaran air. Sampel air yang dianalisis adalah sampel komposit yang diambil dari bagian dasar perairan dan permukaan perairan. Pengambilan sampel air dilakukan pada inlet sungai, lokasi pemukiman, sekitar keramba, serta kondisi alami air danau. Analisis kualitas air dilakukan secara in situ untuk parameter pH, suhu, kecerahan, TDS, DO, sedangkan analisis laboratorium dilakukan untuk parameter BOD, COD, TSS, fosfat, dan nitrat.  Hasil penelitian menunjukkan parameter suhu pada ke 5 titik pengamatan berkisar antara 28°C-31°C, kecerahan 0,66 m-0,86 m, pH 5,9-6,9, DO 2,92 mg/L-5,42mg/L, BOD 2,28 mg/L-3,9 mg/L, COD 24,26 mg/L-25,20 mg/L, TSS 30,18 mg/L- 50,10 mg/L, TDS 594,8 mg/L-950 mg/L, Fosfat 0,1 mg/L- 0,28 mg/L, dan Nitrat 5,97 mg/L-9,8 mg/L. Kata Kunci: Danau Kandung Suli, Kualitas Air.
PENGARUH KEBISINGAN TERHADAP KOMUNIKASI PEKERJA PABRIK PT. X, KECAMATAN MANIS MATA, KABUPATEN KETAPANG
Authors: Suci Pramadita Vilda Rahmawati Yulisa Fitrianingsih
Published: July 2019

ABSTRAKPT. X merupakan salah satu perusahaan perkebunan kelapa sawit yang berlokasi di Kecamatan Manis Mata, Kabupaten Ketapang. Proses produksi minyak kelapa sawit menggunakan mesin berkapasitas tinggi dan pengoperasian cukup panjang. Dimana kegiatan tersebut berpotensi menimbulkan kebisingan yang dapat mengganggu kesehatan pekerja salah satunya gangguan komunikasi. Sementara itu, Peraturan Menteri Tenaga Kerja dan Transmigrasi No. 13 tahun 2011 telah menetapkan bahwa nilai ambang batas kebisingan sebesar 85 dB. Tujuan penelitian ini yaitu mengidentifikasi sumber mesin produksi yang berpotensi menghasilkan kebisingan melebihi nilai ambang batas dan mengidentifikasi pengaruh tingkat kebisingan terhadap komunikasi pekerja yang terpapar kebisingan melebihi nilai ambang batas. Berdasarkan hasil pengukuran, sumber stasiun produksi yang berpotensi menghasilkan tingkat kebisingan melebihi nilai ambang batas tertinggi tanpa dipengaruhi aktivitas stasiun produksi lainnya terjadi pada stasiun power house dengan nilai sebesar 96,2 dB dan tingkat kebisingan terendah terjadi pada stasiun loading ramp dengan nilai sebesar 66,8 dB. Sedangkan tingkat kebisingan melebihi nilai ambang batas tertinggi dengan dipengaruhi aktivitas stasiun produksi lainnya terjadi pada stasiun kernel dengan nilai sebesar 97 dB dan tingkat kebisingan terendah terdapat pada stasiun loading ramp dengan nilai sebesar 69,3 dB. Hasil statistik menggunakan SPSS versi 18.0 dengan uji regresi sederhana didapatkan dari hasil kuesioner menunjukkan bahwa pengaruh tingkat kebisingan terhadap komunikasi pekerja yang terpapar kebisingan melebihi nilai ambang batas sebesar 21% yang termasuk dalam tingkatan “rendah”. Dimana nilai tersebut menyatakan bahwa kebisingan memiliki pengaruh yang signifikan terhadap komunikasi pekerja, yang dapat dilihat pada hasil tes audiometri. Berdasarkan hasil uji audiometri dari 32 responden, 59% diantaranya mengalami penurunan daya dengar dengan kategori tingkat pengaruh “gradasi berat”.Kata Kunci : Tingkat Kebisingan, Sumber Bunyi, Komunikasi Pekerja
ANALISIS KEARIFAN LOKAL MASYARAKAT DALAM MENJAGA SUMBER DAYA AIR
Authors: Dian Rahayu Jati Guido Dwi Admojo Kartini
Published: July 2019

ABSTRAKKearifan lokal ikut berperan dalam pengelolaan sumberdaya alam dan lingkungannya. Namun demikian kearifan lokal juga tidak lepas dari berbagai tantangan seperti: bertambahnya terus jumlah penduduk, teknologi modern dan budaya, modal besar serta kemiskinan dan kesenjangan. Layaknya masyarakat Desa Pisak memberlakukan larangan-larangan yang diterapkan oleh masyarakat Desa untuk menjaga kelestarian DAS (Daerah Aliran Sungai) Sungai agar tidak menciptakan kerusakan yang berdampak buruk bagi masyarakat setempat. Penelitian ini bertujuan menganalisis peran masyarakat dalam menjaga kelestarian sumber daya air, serta menganalisa implementasi masyarakat dalam menjaga kelestarian sumber daya air dilihat dari perbandingan peta selama 2 tahun. Penelitian menggunakan metode tringulasi yaitu kombinasi dari teknik pengumpulan data dengan menggunakan metode wawancara mendalam, pengamatan berperanserta terbatas dan penelusuan (analisis) data sekunder, serta menghitung jumlah penggunaan lahan selama 2 tahun. Dari hasil penelitian di dapat masyarakat Desa Pisak masih menerapkan aturan-aturan atau larangan seperti dilarang menebang pohon secara sembarangan, dilarang memasuki hutan secara sembarangan selain itu juga masyarakat masih memegang teguh adatistiadat yang berasal dari leluhur mereka dengan masih melaksanakan ritual adat. Untuk jumlah penggunaan lahan DAS sungai Tanggi memiliki luasan 14,069 ha. Luasan penggunaan lahan Desa Pisak pada tahun 2016 sebesar 405,301 ha, sedangkan untuk tahun 2105 sebesar 395,379 ha pengurangannya selama 2 tahun sebesar 9,922 ha. Pengurangan tersebut disebabkan kebakaran hutan yang terjadi pada tahun 2015, lahan yang terbakar diambil alih oleh pemerintan untuk dilakukan proses pemulihan lahan.Kata kunci:Kearifan Lokal, Sumber Daya Air,  Penggunaan Lahan
ReaxFF Parameter Optimization with Monte Carlo and Evolutionary Algorithms: Guidelines and Insights
Authors: Shchygol Ganna , Yakovlev Alexei , Trnka Tomáš , C.T. van Duin Adri , Verstraelen Toon
Published: July 2019

ReaxFF is a computationally efficient force field to simulate complex reactive dynamics in extended molecular models with diverse chemistries, if reliable force-field parameters are available for the chemistry of interest. If not, they must be optimized by minimizing the error ReaxFF makes on a relevant training set. Because this optimization is far from trivial, many methods, in particular genetic algorithms (GAs), have been developed to search for the global optimum in parameter space. Recently, two alternative parameter calibration techniques were proposed, i.e. Monte-Carlo Force Field optimizer (MCFF) and Covariance Matrix Adaptation Evolutionary Strategy (CMA-ES). In this work, CMA-ES, MCFF and a GA method (OGOLEM) are systematically compared using three training sets from the literature. GA shows the smallest risk of getting trapped into a local minimum, whereas CMA-ES is capable of reaching the lowest errors for two third of the cases. For each method, we provide reasonable default settings and our analysis offers useful guidelines for their usage in future work. An important side effect impairing the parameter optimization is numerical noise. A detailed analysis reveals that it can be reduced, e.g. by using exclusively unambiguous geometry optimizations in the training set. Even without this noise, many distinct near-optimal parameter vectors can be found, which opens new avenues for improving the training set and detecting overfitting artifacts.
Energy vs. Entropy in Superlattices of Ligand-Covered Nanoparticles
Authors: Fan Zhaochuan , Gruenwald Michael
Published: July 2019

Nanoparticles covered with short ligands tend to self-assemble into face-centered cubic (fcc) superlattices, while nanoparticles with longer ligands preferentially form body-centered cubic (bcc) superlattices. The thermodynamic driving forces for these structures are not fully understood and conflicting theories have been proposed. In this paper, we systematically study the thermodynamic stability of fcc and bcc superlattices as a function of ligand length, core size, and ligand coverage with a coarse-grained molecular model. Our simulations reveal that bcc superlattices are stabilized via two fundamentally different mechanisms, depending on ligand length. For shorter ligands, the bcc superlattice has a lower potential energy than fcc, due to additional interactions between ligands on next-nearest neighbors in the superlattice. For longer ligands, the bcc superlattice is stabilized due to a larger configurational entropy of ligands.
Torquoselectivity of the Ring-Opening Reaction of 3,3-Dihalosubstituted Cyclobutenes: Lone Pair Repulsion and Cyclic Orbital Interaction
Authors: Naruse Yuji , Takamori Atsushi
Published: July 2019

Three major factors determine torquoselectivity, which is the diastereoselectivity in electrocyclic ring-opening reactions to produce E/Z-double bond(s). One is the interaction between the decomposing sCC bond and low-lying vacant orbital(s), such as a p*- or s*-orbital on the substituent, which promotes the reaction, resulting in inward rotation of the substituent. Second, for a substituent with a lone pair(s), repulsive interaction between the decomposing s-bond and the lone pair(s) hinders inward rotation, so that the products of outward rotation should be preferred. Finally, a more strongly donating s-electron-donating group (sEDG) rotates inwardly due to stabilization by phase-continuous cyclic orbital interaction. We compared the latter two interactions, repulsion between the lone pairs on the substituent and stabilization from phase-continuous cyclic orbital interaction, to determine which has a greater effect on the diastereoselectivity. We considered a series of model reactions with halogen substituents, and concluded that the diastereoselectivity is mainly controlled by cyclic orbital interaction.
Linguagem da Pele
Authors: Garcia Fernanda de Deus , Ferreira Alice Maria de Araújo
Published: July 2019

Este artigo tem como objetivo estabelecer as formas de contato entre a etnografia e a tradução, além de propor uma tradução etnográfica de um relato de uma filha de imigrante. Entende-se a etnografia como a observação do outro para estranhar a si mesmo, e esta é usada como um método do traduzir, em que a alteridade e o devir são objetos de estudo do tradutor. Refuta-se a ideia de tradução enquanto passagem, para começar a pensar a tradução enquanto contato de línguas. Usaremos a teoria de François Laplantine sobre o olhar enquanto construído pela lente cultural e sua proposta de se colocar o observador (tradutor) sob a lente do microscópio para poder estranhar-se a si mesmo e sua identidade a fim de tentar alcançar a alteridade diante do contato com a identidade do outro. Ademais, este trabalho se baseia na obra de Henri Meschonnic, buscando entender o traduzir enquanto experiência a partir de uma po-ética, em que se reconhece a inseparabilidade entre linguagem, literatura e historicidade, e a partir da qual não se pode pensar a tradução senão como contato. Por fim, propõe-se colocar em prática essa análise teórica sobre tradução etnográfica ao traduzir um relato sobre imigração escrito por uma filha de uma imigrante nos Estados Unidos, procurando não apagar a alteridade.

 

Palavras-chave: Tradução Etnográfica, Alteridade, Imigração, Relato.
Caderno de fiado
Authors: Benitez Almeida Maria Liz , Lins Almeida Luiz Roberto
Published: July 2019

Este trabalho apresenta uma proposta de tradução comentada do conto La libreta de almacén, do escritor paraguaio Mario Halley Mora, publicado em 1987, no livro Cuentos, microcuentos y anticuentos.

 Palavras-chave: tradução comentada, literatura paraguaia, Mario Halley Mora.
MODEL TARIKAN PERGERAKAN ORANG DENGAN ANALISA REGRESI DI KAMPUS UNIVERSITAS SEMARANG
Authors: Cahyono Dhamang Budi , Muldiyanto Agus , Kustirini Anik
Published: July 2019

ABSTRAK

 
Perkembangan jumlah mahasiswa dari tahun ke tahun semakin  meningkat sehingga hubungan interaksi yang terjadi antara mahasiswa, dosen, karyawan dan pengelola di Kampus Universitas Semarang (USM)  juga meningkat, hal ini dapat menimbulkan potensi kemacetan lalu lintas maupun penambahan fasilitas kebutuhan ruang parkir kendaraan. Penelitian ini bertujuan untuk mengetahui besarnya estimasi prediksi tarikan pergerakan orang menuju Kampus USM. Metode yang digunakan dalam membuat model adalah dengan analisis regresi, dengan variabel bebas adalah PDRB Kota Semarang dan variabel tetapnya adalah jumlah mahasiswa aktif kelas pagi dan sore. Hasil persamaan regresi tarikan ke kampus yang didapat adalah untuk semester gasal kelas pagi adalah Y1 = 1308,803 + 0,032 X, dan persamaan untuk semester genap kelas pagi adalah Y2 = 1568,960 + 0,032 X4. Prediksi tarikan mahasiswa kelas ke Kampus USM pada tahun 2023 untuk semester gasal sebesar 8.635 orang dan untuk semester genapnya sebesar 7173 orang, sedangkan untuk kelas sore semester gasal adalah sebesar 9.756 orang dan untuk semester genap kelas sore sebesar 8.342 orang. Prediksi pada tahun 2023, mahasiswa pengguna sepeda motor terbesar terjadi pada semester gasal kelas sore sebesar 8.369 buah. Sedangkan prediksi pada tahun 2023, mahasiswa penggun mobil terbesar terjadi pada semester gasal kelas sore yaitu sebesar 673 buah
Hubungan Komunikasi Verbal Orang Tua Terhadap Kesantunan Berbahasa Anak di Taman Kanak-Kanak Negeri 1 Kota Padang
Authors: Rambe Sahriana Desi , Muryanti Elise
Published: July 2019

Tujuan penelitian untuk melihat bagaimana hubungan komunikasi verbal orang tua terhadap kesantunan berbahasa anak di Taman Kanak-kanak Negeri 1 Kota Padang. Penelitian ini termasuk jenis penelitian kolerasional dengan menggunakan metode kuantitatif yang melibatkan tindakan pengumpulan data yang berupa angket. Dan pengolahan data menggunakan program SPSS versi 21. Berdasarkan analisis data diperoleh koefisien determinasi komunikasi verbal orang tua terhadap kesantunan berbahasa anak sebesar 0,294, koefisien kolerasi antara hubungan komunikasi verbal orang tua terhadap kesantunan berbahasa anak sebesar 0,241. Hal ini berarti komunikasi verbal orang tua sebesar sebesar 49,1% terhadap kesantunan berbahasa anak signifikan pada taraf 5% . dapat disimpulkan bahwa komunikasi verbal orang tua memiliki hubungan yang signifikan terhadap kesantunan berbahasa anak di Taman Kanak-kanak Negeri 1 Kota Padang sebesar 49,1%.
Urgensi Diklat Berjenjang Tingkat Dasar Pendidik Pada Peningkatan Kompetensi Guru Raudlatul Athfal Bekerjasama dengan IGRA dan Himpaudi Kabupaten Pasuruan
Authors: Rochanah Luluk
Published: July 2019

Penelitian ini bertujuan a). Mengetahui pentingnya   diklat berjenjang tingkat dasar pada kompetesi pendidik Raudlatul Athfal  Kabupaten Pasuruan b). Mengetahui mengetahui bagaimana pengaplikasian diklat berjenjang tingkat Dasar Pendidik RA Kabupaten Pasuruan c). Mengetahui  kualitas pendidik dalam menyelaraskan sikap perilaku setelah mengikuti diklat berjenjang tingkat dasar. Penelitian ini menggunakan pendekatan kualitatif yang menggunakan pendekatan berdasarkan perspektif fenomenologis. Analisis dilakukan dengan pendekatan fenomenologis, observasi dan selfreport. Data yang terkumpul diidentifikasi berdasarkan ketiga komponen Developmental Appropriateness Practices (DAP). Penelitian ini menghasilkan simpulan Kualitas guru tidak dapat dikalahkan oleh sitem pendidikan   dalam mempengaruhi kualitas pendidikan dengan kata lain sebaik apapun sistem pendidikan jika tidak di ikuti dengan kualitas guru yang baik maka kualitas tidak dapat meningkat dengan maksimal, diklat berjenjang tingkat dasar merupakan salah satu  pembinaan atau peningkatan kompetensi pendidik, terlihat pada hasil dari kegiatan Diklat Berjenjang yaitu (1) banyak guru Raudlatul Athfal  yang belum memahami metode pembelajaran untuk diterapkan pada kegiatan belajar mengajar  anak usia dini setelah mengikuti diklat berjenjang, guru Raudlatul Athal lebih memahami metode untuk diterapkan pada kegiatan pembelajaran anak usia dini (2) kegiatan diklat berjenjang tingkat dasar dapat menambah wawasan ilmu pengetahuan tentang anak usia dini (3) Guru Raudlatul Athfal dapat menyusun   manajemen  dan perangkat pembelajaran dengan sempurna  mulai dari kegiatan perencanaan, pelaksanaan , pengamatan hingga evaluasi guru dapat menyusun dengan baik (4) materi yang telah di berikan pada diklat berjenjang tingkat dasar sangat sesuai dengan permasalahan  dan kebutuhan yang di alamai oleh guru Raudlatul Athfal
Pengaruh Metode Bernyanyi Terhadap Ekspresi Emosi Anak di Taman Kanak-Kanak Jabal Rahmah Padang
Authors: Resika Nadia , Yeni Indra
Published: July 2019

Metode yang dapat mengembangkan ekspresi emosi anak adalah dengan menggunakan metode bernyanyi, berdasarkan latar belakang masalah  yang peneliti temukan,  penelitian  ini  ingin mengetahui sejauh  mana pengaruh metode bernyanyi terhadap ekspresi emosi anak. Pendekatan penelitian menggunakan quasy eksperiment dengan  subjeknya yaitu kelompok B1terdiri dari  10 anak dimana 6 anak laki-laki dan 4 perempuan, dan kelompok B2 terdiri dari10 anak dimana 7 anak laki-laki dan 3 perempuan.Teknik pengumpulan data yang digunakan yaitu  tes perbuatan, dengan alat pengumpulan  data menggunakan lembaran pernyataan, berikutnya dikelola menggunakan uji perbedaan (t-test) data. Hasil penelitian  menunjukkan  kelas ekspreimen dengan  metode bernyanyi  mendapatkan  nilai rata-rata lebih tinggi 88,75 dibandingkan dengan  yang berada di kelas kontrol 78,12   menggunakan  metode bermain peran. Terlihat  thitung > ttabel yaitu 2,41590 > 2.10092. Dapat ditarik kesimpulan bahwa metode bernyanyi mempengaruhi ekspresi emosi anak di Taman Kanak-Kanak Jabal Rahmah Padang tahun ajaran 2018/2019
Pengaruh Permainan Outbound Terhadap Perkembangan Sosial Anak di Taman Kanak-Kanak Kemala Bhayangkari 03 Alai Padang
Authors: Rahmadani Aisyah , Yaswinda Yaswinda
Published: July 2019

Tujuan dari penelitian ini untuk mengetahui pengaruh permainan outbound terhadap perkembangan sosial anak di Taman Kanak-kanak Kemala Bhayangkari 03 Alai Padang. Penelitian ini penelitian kuantitatif dengan pendekatan Quasi Eksperiment. Populasi penelitian ini adalah seluruh anak di Taman Kanak-kanak Kemala Bhayangkari 03 Alai Padang, teknik pengambilan sampel Purposive sampling, yaitu kelas B5 dan B6 yang masing-masingnya berjumlah 12 anak. Teknik pengumpulan data menggunakan observasi. Kemudian data diolah dengan uji perbedaan (t-test). Berdasarkan analisis data, diperoleh rata-rata tes kelas eksperimen adalah 82,81 dan SD sebesar  6,81 sedangkan kelas kontrol adalah 69,27 dan SD sebesar 5,96 pada pengujian hipotesis diperoleh t hitung sebesar (4,97794 dan t tabel sebesar 2,07387) pada taraf nyata α = 0,05 dan dk = 22. Dapat disimpulkan permainan outbound berpengaruh terhadap perkembangan sosial anak di Taman Kanak-kanak Kemala Bhayangkari 03 Alai Padang tahun ajaran 2018/2019.
El entorno corre y los ciberriesgos vuelan
Authors: Posada Daza Juan Mario
Published: July 2019

Seguimos buscando la manera más efectiva de afrontar los desafíos que trae consigo la Revolución Industrial 4.0 que, en el marco del contexto digital, potencializa el uso de la computación para abordar algunas actividades rutinarias y mecánicas, tradicionalmente ejecutadas por personas e integra el uso de la inteligencia artificial para plantear la solución de problemáticas que eran resueltas también por los trabajadores de las empresas.
Electrodeposition of Nickel Particles and their Characterization
Authors: Martínez Gerardo T. , Zavala Genaro , Videa Marcelo
Published: July 2019

Electrodeposition of nickel particles on ITO substrates is achieved by current pulse reduction. A comparison between potential pulse and current pulse experiments presents differences in particle size and particle size distribution. The latter shows smaller particle size dispersion than what is found with potential pulses. Characterization of the particles carried out by Atomic Force Microscopy shows particles with average sizes between 100 to 300 nm. Magnetic characterization by Magnetic Force Microscopy and SQUID shows that particles of ~300 nm were ferromagnetic with a coercive field of 200 Oe and a saturation magnetization of 40 × 10-6 emu at 300 K.
Kinetics and Recovery of Xanthate-Copper Compounds by Ion Flotation Techniques
Authors: Reyes Martín , Patiño Francisco , Tavera Francisco J. , Escudero Ramiro , Rivera Isauro , Pérez Miguel
Published: July 2019

The recovery of copper in aqueous media by ion flotation in a laboratory flotation cell was carried out. Hydrodynamics and gas dispersion parameters were obtained. The results show that the increase of potassium amyl xanthate concentration above the stoichiometric amount considerably affects the efficiency of the separation of copper. In a stage of flotation with recirculation, recoveries of 58% and 66 % were obtained with the flat and the cylindrical spargers respectively. The dispersion parameters and bubble surface area flux (Sb) show a good relation with the apparent flotation rate constant (k), even when the superficial gas velocity is 0.8 cm/s, where we can find the appropriate hydrodynamic conditions to carry out the ion flotation. The system subsequently changes from a homogeneous bubble flux to a turbulent flux. Gas dispersion results show that superficial gas velocity, superficial liquid velocity, dispersion system geometry and the simulated malfunction of spargers considerably affect the recovery of copper in a multi stage system of five flotation cells. The best recoveries were obtained at low superficial gas velocities, achieving efficiencies of 94%, 90% and 95 % with the flat, cylindrical and battery of four spargers respectively.
A Search for Structural Alternatives of RNA
Authors: Krishnamurthy Ramanarayanan
Published: July 2019

This account describes a search for potentially primordial informational oligomers; the work is the direct outcome of the research program that was initiated by the Eschenmoser group —at ETH Zürich about 20 years ago and was continued at The Scripps Research Institute since 1996— in order to understand the chemical basis on which nucleic acids were chosen by nature as the molecular foundation of its genetic apparatus. The investigation began with the study of the base-pairing properties of structural alternatives of nucleic acids —constructed from different sugars (hexo- & pentopyranoses and tetrofuranose) retaining the canonical nucleobases and phosphates. The outcome from these studies led to the conclusion that Watson-Crick type base-pairing is not unique to RNA/DNA, and that it can be compatible with a wide variety of backbone edifice. This provided the motivation to map the landscape of potentially primordial informational oligomer systems that may contain backbones, recognition elements and linker groups structurally quite different from those known so far. The oligomer systems chosen for study are, conceptually, deemed to be (a) potentially primordial (based on the nature of the starting materials and reaction conditions considered to be prebiotically realistic) and (b) informational (based on their ability to adopt a repetitive conformation such that the information encoded by the recognition elements can be transmitted intermolecularly). Though such studies suggest the possibility of finding informational systems that could lay claim as functional ancestors of RNA —they are more likely to generate results that provide the opportunity to assess the structural and functional uniqueness of nature’s choice. The experimental investigation described here deals with the base-pairing properties of oligomer systems derived from 2,4-disubsituted -triazines, -5-aminopyrimdines and -6-carboxy pyrimidines as recognition elements that are tagged to oligo-dipeptide backbones via different linker groups. The results from the inter- and intra-system cross-pairing studies reveal that there is, on first approximation, a direct correlation between the magnitude of the difference in DpKa of the recognition elements and their base-pairing strength —smaller the Dpka between the base-pairing partners, weaker is the base-pairing strength (in aqueous medium at near neutral pH). These results exemplify the inherent singularity of the canonical nucleobases— their ability to remain un-ionized under physiological conditions based on their constitution – emphasizing the relationship between their physicochemical properties and their functional competence in connection with their role in informational base-pairing.
Oxidation of Some Organic Diols with Trialkylammonium Fluorochromates(VI), R3NH[CrO3F], (R= CH3, C2H5, C3H7 and C4H9) at Room Temperature and Under Microwave Condition
Authors: Ghammamy Shahriar , Khorsandtabar Samira , Moghimi Ali , Sahebalzamani Hajar
Published: July 2019

A mild and efficient method for the mono-oxidation of diols to the corresponding hydroxyaldehydes with trialkylammonium fluorochromates(VI), R3NH[CrO3F] (R= CH3, C2H5, C3H7 and C4H9), in solution at room temperature, and in solution under microwave radiation, is reported. The easy procedure, simple work-up, short reaction times, and excellent yields are advantages of these reagents.
Efficient ‘One Pot’ Nitro Reduction-Protection of γ-Nitro Aliphatic Methyl Esters
Authors: Díaz-Coutiño Francisco D. , Escalante Jaime
Published: July 2019

A simple and efficient protocol has been developed for the direct conversion of γ-nitro aliphatic methyl esters to N-(tertbutoxycarbonyl)amine methyl esters using NH4+HCO2- and Pd/C in the presence of (Boc)2O. There was a significant decrease in the reaction time under these conditions, increased yields and the purity of the products using this ‘one pot’ procedure.
On the Heats of Formation of Alkanes
Authors: Lii Jenn-Huei , Allinger Norman L.
Published: July 2019

A broad diverse test set of alkanes and cycloalkanes previously studied with MM4 calculations has had the heats of formation calculated by several different quantum mechanical methods: HartreeFock, MP2, and MP4, and also by B3LYP and B3LYP + dispersion energy. Overall, three computational methods (MM4, MP4, and B3LYP + dispersion) yield results that are generally of experimental accuracy. These results are analyzed and compared in some detail.
Side-chain opening of steroidal sapogenins to form 22-oxocholestanic skeletons. An approach to analogues of the aglycone of the potent anticancer agent OSW-1
Authors: Fernández-Herrera María A. , Sandoval-Ramírez Jesús , Meza-Reyes Socorro , Montiel-Smith Sara
Published: July 2019

The side-chain opening of 25R and 25S steroidal sapogenins to form 22-oxocholestanic skeletons is described. The transformation was produced under mild conditions providing high yields (70-87%), in a one pot procedure (some acetylated starting material is recovered). This methodology yields 17-deoxy-26-oxy analogues of the aglycone of the potent anticancer agent OSW-1. All products were fully characterized by 1D and 2D NMR; the most representative displacements are briefly discussed.
Photochemical Rearrangement of a 6-Azasteroid Oxaziridine to a Novel 17β-Carbomethoxy-A-homo-B-seco-6-aza-3, 5-androstanedione
Authors: Frye Stephen
Published: July 2019

4- and 6-azasteroids have been shown to be potent inhibitors of human 5α-reductase and certain azasteroids have shown significant clinical benefit in the treatment of androgen-related disorders. In an effort to expand the diversity of steroidal heterocycles synthetically accessible for structure-activity relationship exploration, a novel reaction sequence was applied to the preparation of the 6-azasteroid framework. To this end, photolysis of the oxaziridine derived from 17β-carbomethoxy-3β-triisopropylsilyloxy-6-azaandrost-5-ene (1) yielded a novel 7, 5-steroidal ring system that was evaluated for inhibition of human type 1 and 2 5α-reductase.
On the Origin of the Conformationally Non-Interconvertable Isomers of Bisphenyldirhodium(III) Caprolactamate
Authors: Xie Jian-Hua , P. Doyle Michael
Published: July 2019

A plausible explanation for the unprecedented formation of two conformational isomers of bisphenyldirhodium(III) caprolactamate is presented. The presence of acetic acid during the coupling process leading to the formation of bisphenyldirhodium(III) caprolactamate is shown to increase the propeller conformer at the expense of the biplanar conformer, Acetic acid is also found to catalyze the decomposition of bisphenyldirhodium(III) caprolactamate with the propeller conformation reacting at a rate that is more than ten times greater than that for the biplanar conformation. We speculate that protonation of one of the caprolactamate ligands changes the orientation of the phenyl ring in its approach to rhodium in the product-forming step of the arylation reaction leading to the formation of the two conformational isomers.
Reactions of Vinylcyclopropane and Bicyclopropyl Compounds With Maleic Anhydride
Authors: Jankowski C. K. , Pelletier A. , Díaz Eduardo , R. Belanger Jacqueline M. , J. Paré J.R. , Lamouroux C. , Boivin J.
Published: July 2019

Vinylcyclopropane and bicyclopropyl C6 compounds are studied as diene precursors in the Diels-Alder reaction. Their rearrangement under different thermal and microwave conditions leads to specific isomeric hexa-, penta- or butadienes, condensed with maleic anhydride as a dienophile. Adduct stereochemistries were compared to those of previously-synthesized model compounds, and are fully characterized with 2D NMR and GC-MS spectroscopies. Some unsaturated terpenes bearing vinylcyclopropane moieties were also condensed, and their adduct structures assigned.
Zinc Electrodeposition from Chloride Solutions onto Glassy Carbon Electrode
Authors: Mendoza-Huízar Luis Humberto , Rios-Reyes Clara Hilda , Gómez-Villegas María Guadalupe
Published: July 2019

An electrochemical study of zinc deposition was carried out in baths containing 0.5 M ZnCl2 and 0.4 M H3BO3. From the voltammetric study it was found that, in our experimental conditions, zinc electrodeposition is quasi-reversible and occurs under charge transfer control. The average coefficient diffusion calculated was D = 7.14 × 10-6 cm2s-1 while the standard constant at electrode charge was 8.78 × 10-3 cms-1. The nucleation and growth parameters determined from the potentiostatic study showed that, at bigger overpotentials, a vertical growth is favored, suggesting a dendritic growth. The critical cluster´s size calculated was 2, indicating that each active site is formed by two zinc atoms on the glassy carbon electrode (GCE) surface, while the ΔG for the formation of stable nucleus was 1.35 × 10-20 J/nuclei. The Scanning Electron Microscopy images showed thin platelets of hexagonal crystals and dendrites at lower and higher overpotentials applied, respectively.
Characterization of Copolymer Based in Polyurethane and Polyaniline (PU/PANI)
Authors: Rangel-Vázquez Norma Aurea , Salgado-Delgado René , García-Hernández Edgar , Mendoza-Martínez Ana María
Published: July 2019

The present work describes the synthesis and characterization of polyurethane (PU), polyaniline (PANI) and three IPNs (90/10, 80/20, 70/30) ratios were characterized by Fourier transformed infrared (FTIR) to analyze the generated functional groups of the synthesis. The combination PU/PANI was accomplished through the interconnection of the two polymers via condensation of PU prepolymer terminal NCO groups and the amine groups of PANI. DMA studies indicated that the PU had higher glass transitiontemperatures (Tg) with the increase of PANI. SEM micrographics were obtained to 1000X of the PU, PANI and the ratios 90/10, 80/20 and 70/30 of PU/PANI. A morphological interpretation was proposed in which PANI chains formed a phase dispersed in a PU matrix, linked together by an interphase, that could be responsiblefor the connectivity between the two polymers and determine excellent mechanical properties.
Znx-1CuxMn2O4 Spinels; Synthesis, Structural Characterization and Electrical Evaluation
Authors: Méndez-Martínez Francisco , González Federico , Lima Enrique , Bosch Pedro , Pfeiffer Heriberto
Published: July 2019

This work presents the structural characterization and electrical evaluation of Znx-1CuxMn2O4 spinels, which are materials presented as secondary phases into the varistor ceramic systems. Samples were analyzed by X-ray diffraction, solid-state nuclear magnetic resonance, infrared spectroscopy, scanning electron microscopy and impedance spectroscopy. Although, the addition of copper to the ZnMn2O4 spinel did not produce morphological changes, the structure and electrical behaviors changed considerably. Structurally, copper addition induced the formation of partial inverse spinels, and its addition increases significantly the electrical conductivity. Therefore, the formation of Znx-1CuxMn2O4 spinels, as secondary phases into the varistor materials, may compromise significantly the varistor efficiency.
 
Ceramic, Impedance Spectroscopy, spinel, Varistor, XRD.
Spectrophotometric Determination of the First Hydrolysis Constant of Praseodymium (III)
Authors: González-Mendoza Roberto , López-González Hilario , Rojas-Hernández Alberto
Published: July 2019

The behavior of the trivalent ion praseodymium in 2M of NaCl at 303 K and in CO2 free conditions, was studied. Spectrophotometric titrations of the soluble species were used, in order to obtain the value of the first hydrolysis constant of Pr(III). The data obtained were treated with both the program SQUAD and by a graphic method, respectively. The result obtained using SQUAD was log*ß1 = –8.94 ± 0.03, while it was log*ß1 = –8.77 ± 0.03, when calculated graphically. These results are similar to the value obtained previously with the potentiometric method.
Formation of Two 1:1 Chlorogenic Acid: β-cyclodextrin Complexes at pH 5: Spectroscopic, Thermodynamic and Voltammetric study †
Authors: Álvarez-Parrilla Emilio , Palos Ricardo , De la Rosa Laura A. , Frontana-Uribe Bernardo A. , González-Aguilar Gustavo Adolfo , Machi Lorena , Ayala-Zavala Jesús Fernando
Published: July 2019

Complexation of chlorogenic acid (CA) by b-cyclodextrin (b-CD) at mildly acidic pH, was studied by fluorescence spectroscopy, isothermal titration calorimetry (ITC), cyclic voltammetry (CV) and NMR spectroscopy. Thermodynamic parameters (DH°, DS° and K) determined by both fluorescence and ITC, showed that the complexation of CA by b-CD is an enthalpy-driven process. Results show that CA molecule can be complexed through both polyphenolic and quinic acid moiety, leading to the formation of two supramolecular isomers with 1:1 stoichiometry.
Isosteric Heats of Adsorption of N2O and NO on Natural Zeolites
Authors: Domínguez Gerardo , Hernández-Huesca Rosario , Aguilar-Armenta Gelacio
Published: July 2019

We studied the capacities of three natural zeolites to adsorb N2O or NO using a glass high-vacuum volumetric system that permitted characterization of the energetics of the adsorption process. Adsorption equilibrium data were analyzed using the classical Freundlich equation and the Dual–Langmuir model. We employed the Clausius–Clapeyron relationship to calculate the isosteric heats of adsorption using the equilibrium data of the isotherms measured at 273.15 K and 293.15 K. The isosteric heats of reversible adsorption of both gases were smaller than the heats of total adsorption. The interaction energy of N2O with mordenite was larger than the interaction energies of N2O with either erionite or clinoptilolite. The interaction energy of NO was found to be largest with erionite.
Synthesis, Solid and Solution Studies of Paraquat Dichloride Calixarene Complexes. Molecular Modelling
Authors: García-Sosa Irma , Ramírez Flor de María
Published: July 2019

The interaction of the herbicide paraquat dichloride (PQ,substrate) with p-tert butylcalix[6,8]arenes (L, receptor) was investigated in both the solution and solid states. The isolated paraquat calixarene complexes were characterised by UV-visible, 1H NMR, ESI-MS, Luminescence and IR spectroscopies and elemental analysis. The stoichiometry of complexes 1 and 2 was 1:1 (1 herbicide:1 calixarene) and both revealed a biexponential luminescence decay with lifetimes depending on the size and the conformational particularity of the calixarenes. Molecular modelling suggested that both calixarenes interact with the herbicide through cation-π interaction. PQ is included in the p-tert-butylcalix[8]arene cavity, a situation favoured by its pinched conformation in polar solvent while it is partially included in the p-tert-butylcalix[6]arene cavity because of its in-out cone conformation. The theoretical results, in particular using MOPAC procedures, were in agreement with the experimental findings.
Synthesis of Peptides Histamine H2 Receptors in Solid-Phase Assisted by Microwave
Authors: Reynoso-Soto Edgar A. , Rivero Ignacio A.
Published: July 2019

The synthesis of histamine H2 receptors peptides was conducted using the methodology of solid phase assisted by microwaves. Microwaves can reduce the reaction times during the coupling and deprotection steps to obtain the desired peptide sequence. The coupling reaction was carried out with a mixture of N,N′-diisopropylcarbodiimide (DIC) and N,N,N′,N′-tetramethyl-O-(1H-benzotriazol-1-yl)uronium hexafluorophosphate (HBTU). The purity and yield are improved in peptide synthesis assisted by microwaves. Coupling reactions and deprotection on Rink resin were carried out in 5 min depending on amino acid and the length of the peptide chain.
Electrochemical Behavior of Ni-Mo Electrocatalyst for Water Electrolysis
Authors: Fernández-Valverde Suilma Marisela , Ordoñez-Regil Eduardo , Cabañas-Moreno Gerardo , Solorza-Feria Omar
Published: July 2019

Nickel-molybdenum based electrolcatalysts were synthesized in organic media for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media. The structure, morphology, and chemical composition of the catalysts were evaluated by XRD, SEM and AAS. Results revealed nanocristalline powder materials with Ni0.006Mo, Ni0.1Mo, and NiMo compositions. The best performance for HER, was obtained on Ni0.1Mo electrode, whereas NiMo was for the OER. Results suggest that the material with 1:1 stoichiometric ratio could be considered as a promising electrocatalyst for OER. This nanocrystalline powder is formed by Ni2Mo3O8 and a crystalline structure attributed to the possible formation of a NiMo cluster, becomes NiMoO4 .after thermal treatment at 1073K in air. The NiMo 1:1 cluster catalyst presented electrochemical stability during the OER.
Optimization of Ethanol Production Process from Cassava Starch by Surface Response
Authors: López Zamora Leticia , González Calderón José Amir , Trujillo Evangelina , Bolaños Reynoso Eusebio
Published: July 2019

This work shows the study of the optimization process for producing ethanol from cassava starch based on 22 experimental designs with three central points and using statistical software. This methodology was applied to the stage of saccharification of cassava starch by acid hydrolysis as well as to the stage of fermentation using Saccharomyces cerevisiae. From the experimental data of acid hydrolysis, we proposed a first-order kinetic model which presented an average error of 1.87 % compared to the quadratic regression obtained. The development of a semi-continuous process showed a 89.84 % conversion of starch initially considered, yielding an ethanol concentration of 49.76 % Alc/vol.
Sensitive and Selective Extractive Spectrophotometric Method for the Determination of Hydroxyzine Dihydrochloride in Pharmaceuticals
Authors: Rajendraprasad Nagaraju , Basavaiah Kanakapura , Basavaiah Vinay Kanakapura , Doddarevanna Revanasiddappa Hosakere
Published: July 2019

Hydroxyzine dihydrochloride (HDH), a piperazine H1-receptor antagonist and antihistamine, is a rapid acting anxiolytic used principally as an anti-emetic. A sensitive, selective, and precise and accurate spectrophotometric method based on the formation of an ion-pair with orange II (ORG II) as ion-pair complexing agent was developed and validated for the determination of HDH in pharmaceuticals. The chloroform-extractable ion-pair complex exhibited an absorption maximum at 480 nm. Optimization of different experimental conditions is described. Beer’s law is obeyed in the range of 1.5-15 μg mL-1 with an apparent molar absorptivity value of 2.07 x 104 L mol-1 cm-1 and Sandell’s sensitivity value of 0.0216 μg cm-2. The limit of detection (LOD) and limit of quantification (LOQ) are 0.14 and 0.41 μg mL-1, respectively. A Job’s plot of absorbance versus molar ratio of HDH to ORG II indicated (1:2) stoichiometric ratio. Within- and between-day relative standard deviations at three different concentration levels were < 3%. The developed method was successfully applied to commercial tablets. The results obtained were in good agreement with those obtained using the official method.
No interference was encountered from co-formulated substances.
Recoveries were 96-109 %.
Hypoglycemic and Antioxidant Effects of Subcoriacin in Normal and Streptozotocin-induced Diabetic Rats
Authors: Narváez-Mastache José M. , Soto Claudia , Delgado Guillermo
Published: July 2019

Subcoriacin (1) is a 3-aryl-6-prenylcoumarin isolated from Eysenhardtia subcoriacea that has shown antioxidant activity in vitro, and has shown to scavenge free radicals and also to improve the reduced glutathione levels in pancreatic homogenates. The present investigation evaluates the protective effect of 1 against oxidative injury in normal and streptozotocin (STZ)-induced diabetic rats. The i.p. administration of 1 at a dose of 100 mg/kg body weight for 5 d, significantly decreased blood glucose levels and improved the endogenous antioxidant system. Also, a significant increase in the activities of the antioxidant enzymes glutathione peroxidase (GSHPx), superoxide dismutase (SOD) and catalase (CAT) occurred. Combined treatment of rats with 1 (100 mg/kg) and STZ significantly reduced the pancreatic levels of thiobarbituric acid reactive substances (TBARS) levels. Likewise, significant increases in the activities of the antioxidant enzymes together with a decrease in blood glucose levels in both treatments were observed. The results demonstrate and support the relationship between the hypoglycemic and antioxidant activities displayed by the natural compound 1.
Anemia Megaloblástica, generalidades y su relación con el déficit neurológico
Authors: Marín Castro María José
Published: July 2019

Las anemias megaloblásticas agrupan una serie de desórdenes que se caracterizan por el cambio morfológico de los eritrocitos y su alteración en el desarrollo y maduración a nivel de la médula ósea. Las causas de anemia megaloblástica son numerosas, pero en la mayoría de los casos es debido a deficiencia de folatos y vitamina B12. Esta última, se ve involucrada en múltiples procesos fisiológicos y metabólicos incluyendo el desarrollo del sistema nervioso central, la síntesis de neurotransmisores y la integridad celular. El déficit o ausencia de dichos compuestos genera anemia megaloblástica, una condición que deforma las células sanguíneas y causa diversos síntomas tales como fatiga, debilidad, adelgazamiento y en la primera infancia puede generar deficiencias intelectuales y trastornos motores persistentes. Se realizó una búsqueda bibliográfica con el objetivo hacer una revisión de la deficiencia de la vitamina B12 y folatos en relación con sus complicaciones a nivel neurológico.
Impacto de la mastoidectomia en la reparación de la perforación timpánica en pacientes con otitis media crónica no colesteatomatosa con hueso mastoideo esclerótico
Authors: Lugo Machado Juan Antonio , González Quintana José Eduardo , Martínez Villa Francisco Antonio , Portilo Flores Jorge Alberto , Rubio Espinoza Alfonso Antonio
Published: July 2019

Objetivo: Describir las características clínicas  y resultados obtenidos en pacientes a los cuales se les realizó reparación de perforación timpánica   secundaria a otitis media crónica  no colesteatomatosa  con hueso mastoideo esclerótico, con y sin mastoidectomia. Materiales y métodos: estudio  de tipo trasversal comparativo, con un muestreo no probabilístico por serie consecutiva de  casos. Se  revisarón  los expedientes de pacientes  que cumplan con los criterios de inclusión en el periodo comprendido enero del 2015 a mayo 2016. Se tomarón datos como; edad, sexo, estado de procedencia, antecedente de tabaquismo, causa de la perforación, duración del oído seco, datos a la otoscopia, presencia de otorrea transoperatoria y postoperatoria, estado de la mucosa, presencia de timpanoesclerosis o miringoesclerosis, perforación o retracción del injerto. Resultados: Un total de 48 pacientes fueron seleccionados; 31 del sexo femenino y 17  del sexo masculino, con edad promedio de 43,25 años,  el  seguimiento fue de 3 meses.   Al comparar al grupo de paciente con mastoidectomia y sin esta, no se encontró diferencia estadísticamente significativa en cuanto a éxito de la cirugía (perforación de injerto RR 1,2, p 1, otorrea posoperatoria   RR 2,26, p 0;68 y  retracción del injerto RR 0;76,  p 1).  Se encontró que las características durante  y previa a la cirugía  no influyeron en el resultado final, presentando un promedio global  del 94% de integración del injerto. Conclusión: la mastoidectomia no muestra beneficio adicional en la reparación de la membrana timpánica, las características durante  y previa a la cirugía  no influyeron en el resultado final.