WorldWideScience

Sample records for hamzisti ba bakteri

  1. ANALISIS CEMARAN BAKTERI Escherichia coli ANALISIS CEMARAN BAKTERI Escherichia coli ANALISIS CEMARAN BAKTERI Escherichia coli

    OpenAIRE

    ANGGREINI, RAHAYU

    2015-01-01

    2015 RAHAYU ANGGREINI coli Penelitian ini bertujuan untuk melakukan identifikasi cemaran bakteri E. coli O157:H7 pada daging sapi di kota Makassar. Sampel pada penelitian ini sebanyak 72 sampel Kata Kunci : Daging sapi, pasar tradisional, E. coli, E. coli O157:H7, kontaminasi bakteri, identifikasi E. coli O157:H7.

  2. Mikrobiologer ser bakterier i kortene

    DEFF Research Database (Denmark)

    Harmsen, Morten; Sternberg, Claus; Haagensen, Janus Anders Juul

    2008-01-01

    Siden Alexander Fleming opdagede penicillin og dermed de moderne antibiotika, har vi troet, at dødelige infektioner tilhørte historien. Men en udbredt brug af antibiotika har ført til fremkomsten af mange antibiotikaresistente bakterier. Bakterierne beskytter sig blandt andet mod medicinen ved...

  3. Pengaruh Penambahan Bakteri Probiotik yang Dipacu dengan Prebiotik Ubi Jalar Terhadap Penurunan Jumlah Bakteri Shigella dysenteriae Secara In Vitro

    Directory of Open Access Journals (Sweden)

    Safitri Nur Rahmi

    2014-03-01

    Full Text Available Bakteri probiotik adalah mikroba yang bersifat menguntungkan dari golongan Bakteri Asam Laktat (BAL. Antara bakteri yang menguntungkan dan patogen akan  terjadi kompetisi. Pertumbuhan Bakteri Asam Laktat (BAL di usus manusia dapat distimulasi dengan cara memberikan substrat- substrat yang dapat dicerna oleh bakteri tersebut sehingga populasinya meningkat dan melawan bakteri patogen. Substrat- substrat yang dapat digunakan oleh BAL untuk menstimulasi pertumbuhannya dikenal dengan nama prebiotik.   Tujuan penelitian untuk mengetahui pengaruh penambahan berbagai dosis bakteri probiotik Lactobacillus casei terhadap jumlah penurunan bakteri Shigella dysenteriae.   Desain penelitian ini adalah Post Test with Control. Dalam desain penelitian ini terdapat kontrol dan kelompok eksperimen. Penghitungan jumlah Bakteri Shigella dysenteriae dengan menggunakan selektif media Mac Conkey Agar. Data didapatkan dari jumlah bakteri Shigella dysenteriae setelah penambahan probiotik Lactobacillus casei. Pengolahan data menggunakan software pengolah data. Uji statistik yang digunakan adalah One Way Anova dengan taraf signifikan 5%.   Hasil penelitian yang telah dilakukan didapatkan rerata jumlah penurunan bakteri Shigella dysenteriae pada media Mac Conkey Agar adalah 48.14 x 105 CFU/ml, 45.76 x 105 CFU/ml, 42.10 x 105 CFU/ml, 35.90 x 105 CFU/ml, 32.76 x 105 CFU/ml. Hasil uji Anova One Way diperoleh nilai signifikansi 0.000 (<0.05.   Ada pengaruh bermakna penambahan berbagai dosis bakteri probiotik Lactobacillus casei terhadap penurunan jumlah bakteri Shigella dysenteriae

  4. Pengaruh Penambahan Bakteri Probiotik yang Dipacu dengan Prebiotik Ubi Jalar Terhadap Penurunan Jumlah Bakteri Shigella dysenteriae Secara In Vitro

    Directory of Open Access Journals (Sweden)

    Safitri Nur Rahmi

    2014-09-01

    Full Text Available Bakteri probiotik adalah mikroba yang bersifat menguntungkan dari golongan Bakteri Asam Laktat (BAL. Antara bakteri yang menguntungkan dan patogen akan terjadi kompetisi. Pertumbuhan Bakteri Asam Laktat (BAL di usus manusia dapat distimulasi dengan cara memberikan substrat- substrat yang dapat dicerna oleh bakteri tersebut sehingga populasinya meningkat dan melawan bakteri patogen. Substrat- substrat yang dapat digunakan oleh BAL untuk menstimulasi pertumbuhannya dikenal dengan nama prebiotik. Tujuan penelitian untuk mengetahui pengaruh penambahan berbagai dosis bakteri probiotik Lactobacillus casei terhadap jumlah penurunan bakteri Shigella dysenteriae. Desain penelitian ini adalah Post Test with Control. Dalam desain penelitian ini terdapat kontrol dan kelompok eksperimen. Penghitungan jumlah Bakteri Shigella dysenteriae dengan menggunakan selektif media Mac Conkey Agar. Data didapatkan dari jumlah bakteri Shigella dysenteriae setelah penambahan probiotik Lactobacillus casei. Pengolahan data menggunakan software pengolah data. Uji statistik yang digunakan adalah One Way Anova dengan taraf signifikan 5%. Hasil penelitian yang telah dilakukan didapatkan rerata jumlah penurunan bakteri Shigella dysenteriae pada media Mac Conkey Agar adalah 48.14 x 105 CFU/ml, 45.76 x 105 CFU/ml, 42.10 x 105 CFU/ml, 35.90 x 105 CFU/ml, 32.76 x 105 CFU/ml. Hasil uji Anova One Way diperoleh nilai signifikansi 0.000 (<0.05. Ada pengaruh bermakna penambahan berbagai dosis bakteri probiotik Lactobacillus casei terhadap penurunan jumlah bakteri Shigella dysenteriae.

  5. BAKTERI INDIKATOR PENCEMARAN DI PERAIRAN KABUPATEN BANGKALAN

    Directory of Open Access Journals (Sweden)

    Eva Ari Wahyuni

    2015-04-01

    Full Text Available Perairan Selat Madura, khususnya di Kecamatan Kamal dan Socah Kabupaten Bangkalan, merupakan wilayah perairan yang terdampak langsung oleh berbagai aktivitas di Kota Surabaya dan Kabupaten Gresik serta adanya Jembatan Suramadu. Beberapa dampak, salah satunya adalah dampak negative berupa potensi pencemaran di lingkungan perairan laut. Tujuan penelitian ini untuk mengetahui keberadaan bakteri pencemar, salah satu indikatornya adalah bakteri pathogen, di perairan Kecamatan Kamal Kabupaten Bangkalan. Pengambilan data berupa sampel air laut dilakukan di tiga stasiun, dibiakkan dalam media agar. Selanjutnya, proses kultur pada media selektif. Hasil kultur menunjukkan ada bakteri pathogen dari jenis coliform. Keberadaan bakteri pathogen menjadi salah satu indicator awal yang menunjukkan adanya peluang terjadinya pencemaran di lokasi penelitian.Kata Kunci: Bakteri pathogen, Coliform, Indikator pencemaranPOLLUTION INDICATOR BACTERIA IN BANGKALAN DISTRICT WATERSABSTRACTMadura Strait, especially in Sub Kamal and Socah Bangkalan, a water area directly affected by the activities in the city of Surabaya and Gresik as well as the Bridge. Some effects, one of which is in the form of the potential negative impact of pollution in the marine environment. The purpose of this study to determine the presence of bacterial contaminants, one indicator is the bacterial pathogen, in the waters of the District Kamal Bangkalan. Retrieval of data in the form of sea water samples carried out at three stations, cultured in an agar medium. Furthermore, the process of culture in selective media. Culture results showed no coliform bacterial pathogens of this type. The existence of pathogenic bacteria becomes one of the early indicators that indicate the chances of contamination at the sites.Keywords: Coliform, Pathogenic bacteria, pollution indicators

  6. PENAPISAN BAKTERI KITINOLITIK DARI LIMBAH PENGOLAHAN UDANG

    Directory of Open Access Journals (Sweden)

    Ekowati Chasanah

    2009-06-01

    Full Text Available Limbah pengolahan udang merupakan salah satu sumber enzim pendegradasi kitin (enzim kitinolitik potensial. Tulisan ini melaporkan sebagian hasil rangkaian riset mengenai pencarian sumber enzim Kitinolitik dari lingkungan laut, khususnya dari limbah industri perikanan. Tujuan dari riset ini adalah mengisolasi bakteri kitinolitik dan limbah pengolahan udang, mengetahui kondisi optimum untuk memproduksi enzim tarsebut dan mengidentifikasi bakteri terbaik penghasil enzim tersebut. Penapisan diakukan dengan mengevaluasi indeks kitinolitik pada medium kitin padat (2% dan mengukur aktivitas kitinolitik pada medium minimal (MSM cair yang diperkaya koloidal kitin 0,5%. Optimasi produksi enzim dilakukan dengan mangkultur isolat pada berbagai pH, suhu, dan substrat menggunakan penangas air bersuhu 37ºC dengan agitasi 100 rpm. Sejumlah 106 isolat berhasil diisolasi, dan di antaranya isolat KPU 218 yang memiliki aktivitas kitinolitik tertinggi (0,134 ± 0,004 U/mg dalam waktu tercepat (24 jam. Kondisi optimum untuk memproduksi enzim tersebut adalah pH 5, suhu 25ºC dengan substrat koloidal kitin dan waktu produksi 30 jam. Hasil identifikasi berdasarkan 16S-rDNA menunjukkan bahwa isolat KPU 218 memiliki kemiripan 87% dengan Acinetobacter sp.

  7. PEMERIKSAAN BAKTERI PENYEBAB PERIODONTITIS KRONIS DENGAN MENGGUNAKAN METODE POLYMERASE CHAIN REACTION (PCR)

    OpenAIRE

    BASYAR, HUSNUL

    2012-01-01

    2011 Penyakit periodontal merupakan penyakit yang disebabkan oleh infeksi bakteri dan dapat mengakibatkan kerusakan jaringan periodontal. Plak gigi dinyatakan berperan penting dalam inisiasi periodontitis. Periodontitis umumnya disebabkan oleh plak. Plak adalah lapisan tipis biofilm yang mengandung bakteri, produk bakteri, dan sisa makanan. Lapisan ini melekat pada permukaan gigi dan berwarna putih atau putih kekuningan. Plak yang menyebabkan gingivitis dan periodontitis adalah plak yang...

  8. Isolasi dan Identifikasi Bakteri Asam Laktat Penghasil Inhibitor Enzim HMG-KoA Reduktase dari Bekasam sebagai Agen Pereduksi Kolesterol

    OpenAIRE

    Rinto, Rinto; Dewanti, Ratih; Yasni, Sedarnawati; SUHARTONO, MAGGY THENAWIDJAJA

    2015-01-01

    Penelitian ini bertujuan memperoleh bakteri penghasil statin sebagai inhibitor enzim HMG-KoA reduktase (HMGR), penghambat sintesis kolesterol. Tahapan penelitian yang dilakukan adalah isolasi bakteri yang resisten terhadap compactin dan lovastatin, produksi statin, uji penghambatan ekstrak dari kultur bakteri terhadap HMG-KoA reduktase dan identifikasi bakteri. Hasil penelitian menunjukan bahwa dari 20 isolat bakteri yang resisten terhadap compactin maupun lovastatin, terdapat 5 isolat bakter...

  9. KARAKTERISASI BAKTERI ASAM LAKTAT YANG DIISOLASI SELAMA FERMENTASI BAKASANG

    Directory of Open Access Journals (Sweden)

    Dwi Indah widya yanti

    2014-06-01

    Full Text Available Tujuan penelitian ini adalah mempelajari bakteri asam laktat (BAL yang berperan selama fermentasi15 hari pada produk fermentasi bakasang. Selama fermentasi dilakukan pengukuran terhadap pH dantotal asam, total plate count, dan bakteri asam laktat dilanjutkan dengan uji morfologi dan biokimia. Hasilpengukuran pH terjadi kecenderungan penurunan pH pada sampel bakasang disebabkan asam laktat yangdihasilkan oleh aktifi tas BAL. Tiga spesies BAL yang teridentifi kasi yaitu Lactobacillus acidophilus danL. plantarum dengan karakteristik Gram-positif batang, tidak membentuk spora, non motil, indol negatif,katalase negatif, oksidase positif, uji Sitrat bervariasi, Voges-Proskauer (VP bervariasi, methyl red (MRpositif dan hasil fermentasi karbohidrat bervariasi. Streptococcus faecalis dengan karakteristik Gram-positifkokus, non motil, katalase negatif, indol negatif, VP positif, sitrat negatif, dan uji fermentasi karbohidratpositif .Kata kunci: bakasang, bakteri asam laktat, cakalang, karakteristik, nike

  10. EFEK MEDAN LISTRIK AC TERHADAP PERTUMBUHAN BAKTERI Klebsiella Pneumoniae

    Directory of Open Access Journals (Sweden)

    Mokhamad Tirono

    2013-05-01

    Full Text Available Penghambatan pertumbuhan bakteri Klebsiella pneumoniai pada ikan kembung dengan medan listrik alternating current (AC telah dilakukan. Medan Listrik AC yang digunakan divariasi dari 0,38 kV/cm sampai 5 kV/cm dengan frekwensi 50 Hz, sedangkan waktu paparan 10 menit. Pada penelitian ini dilakukan penumbuhan bakteri Klebsiella pneumonia pada media NA selama 24 jam dan berikutnya ditumbuhkan pada medium NB dan ikan yang sudah disterilkan selama 24 jam. Bakteri yang sudah ditumbuhkan pada medium NB dan ikan kemudian dipapar dengan medan listrik AC dengan variasi kuat medan yaitu dari 0,38 kV/cm sampai 5 kV/cm dengan waktu paparan 10 menit. Sehabis dipapar bakteri ditumbuhkan pada medium NB selama 24 jam dan berikutnya diencerkan dengan aquades untuk dihitung jumlah koloninya. Hasil uji menggunkan univariate analysis of variance didapatkan nilai signifisi 0,000 yang menunjukkan ada perbedaan yang signifikan untuk masing-masing kuat medan listrik. Menggunakan statistic post hoc test diperoleh bahwa dengan kuat medan 5 kV/cm mempunyai faktor hambat 0,99, sedangkan  dengan  kuat   medan  0,38   kV/cm  mempunyai  faktor   hambat   0,3.   Terhambatnya pertumbuhan bakteri ini disebabkan oleh karena membran seluler bakteri rusak, sehingga menyebabkan keluarnya materi intraseluler. Kerusakan membran seluler disebabkan oleh terjadinya elektroporasi yang dapat meningkatkan potensial membran. Semakin tinggi medan listrik yang dikenakan, maka peningkatan tegangan transmembran semakin tinggi.

  11. Karakterisasi Bakteri Asam Laktat Amilolitik dari Industri Pengolahan Pati Sagu

    Directory of Open Access Journals (Sweden)

    Yusmarini Yusmarini

    2017-03-01

    Full Text Available Amylolytic lactic acid bacteria are a group of bacteria that are capable to use starch as the carbon source. The objectives of this research were to characterize, and identify the lactic acid bacteria from sago starch processing industry, which might be used to modify the sago starch. There were 39 isolates isolated from sago processing industry, and 36 of them were presumed as lactic acid bacteria. From 36 isolates suspected as lactic acid bacteria, 9 of them had amylolytic properties. Morphological identification results show that the 9 isolates were l Gram-positive bacteria, negative catalase, rod shape, and 5 isolates produced gas, while 4 isolates did not produce gas. The ability to produce amylase varied among isolates and isolate RN2.12112 had the higher amylolytic ability than others. Results show that the nine isolates identified as lactic acid bacteria were dominated by Lactobacillus plantarum 1.   ABSTRAK Bakteri asam laktat (BAL yang bersifat amilolitik adalah bakteri asam laktat yang mampu memanfaatkan pati sebagai substratnya. Tujuan penelitian adalah untuk mengkarakterisasi sifat amilolitik dan mengidentifikasi bakteri asam laktat yang mempunyai kemampuan amilolitik untuk memodifikasi pati sagu. Hasil penelitian memperoleh 39 isolat dari industri pengolahan sagu dan 36 diantaranya diduga sebagai bakteri asam laktat. Sembilan dari 36 isolat yang diduga bakteri asam laktat mempunyai sifat amilolitik. Sembilan isolat yang bersifat amilolitik selanjutnya diidentifikasi secara morfologi yang meliputi pewarnaan Gram, bentuk sel, uji katalase, dan uji kemampuan fermentasi. Hasil identifikasi secara morfologi menunjukkan bahwa kesembilan isolat termasuk kelompok bakteri Gram positif, katalase negatif, bentuk basil, dan lima isolat menghasilkan gas sedangkan empat isolat tidak menghasilkan gas. Kemampuan isolat untuk menghasilkan amilase bervariasi dan isolat RN2.12112 mempunyai kemampuan amilolitik lebih tinggi dibanding isolat lainnya

  12. DETEKSI GEN-GEN PENYANDI FAKTOR VIRULENSI PADA BAKTERI VIBRIO

    Directory of Open Access Journals (Sweden)

    Ince Ayu Khairani Kadriah

    2011-04-01

    menggunakan isolat bakteri yang diisolasi dari budidaya udang windu di berbagai daerah di Sulawesi Selatan dan Jawa. Pada penelitian ini digunakan primer spesifik untuk mendeteksi gen-gen virulen toxR gene, hemolysin (vvh gene, dan GyrB gene dengan metode PCR. Dari 35 isolat yang diisolasi, 20 isolat terdeteksi memiliki gen virulensi dan 8 di antaranya memiliki dua gen virulen. Spesies bakteri yang memiliki gen virulen adalah: V.harveyi, V. parahaemolyticus, V. mimicus, dan V. campbelli

  13. Penapisan Bakteri Penghasil Enzim Kitosanase Yang Berasosiasi Dengan Spons Laut

    Directory of Open Access Journals (Sweden)

    Ekowati Chasanah

    2007-12-01

    Full Text Available Informasi pasar dunia menunjukkan bahwa 50% keperluan dunia akan produk turunan kitin, digunakan untuk produk suplemen kesehatan. Untuk menunjang proses produksi kitosan yang bersifat ramah lingkungan dan aman untuk konsumsi manusia, maka enzim pendegradasi kitin/ kitosan sangat berperan. Penelitian ini bertujuan untuk mendapatkan bakteri penghasil enzim pendegradasi kitosan dari spons. Spons dipilih karena biota laut tersebut dikenal kaya akan senyawa bioaktif dan sebagian besar masa tubuhnya didominasi oleh bakteri. Dari 24 spons, telah berhasil diisolasi 86 isolat bakteri dan 22 di antaranya menghasilkan enzim pendegradasi kitin, termasuk di antaranya enzim kitosanase. Berdasarkan pada nilai indeks kitinolitik (IK dan waktu produksi enzim, isolat KBJ 12 SB telah dipilih sebagai isolat penghasil kitosanase. lsolat tersebut menghasilkan enzim kitosanase maksimal pada hari ke‑5, dengan aktivitas enzim sebesar 0,797 U/mg. Enzim kitosanase yang dihasilkan bekerja optimal pada suhu 60 0C dan pH 8. Enzim stabil pada suhu 370C dengan sisa aktivitas > 50% ketika diinkubasi selama 90 menit. Hasil identifikasi menunjukkan bahwa bakteri KBJ 12 SB memiliki sifat mirip dengan jenis Bacillus sp.

  14. KARAKTERISASI BAKTERI ANTI QUORUM SENSING (AQS SEBAGAI PENGHAMBAT VIRULENSI PENYAKIT PADA IKAN LELE DUMBO (Clarias gariepinus

    Directory of Open Access Journals (Sweden)

    Hessy Novita

    2015-03-01

    Full Text Available Penyakit bakterial adalah salah satu penyebab kerugian besar di bidang akuakultur. Faktor virulensi bakteri penyakit umumnya diekspresikan oleh gen-gen virulen yang diregulasi dengan sistem Quorum Sensing. Tujuan dari penelitian ini adalah untuk mendapatkan isolat bakteri yang memiliki potensi sebagai Anti Quorum Sensing (AQS yang dapat menghambat faktor virulensi bakteri patogen penyebab penyakit pada ikan lele dumbo (Clarias gariepinus. Isolasi bakteri dilakukan dari sedimen, organ pencernaan dan air kolam ikan lele dumbo dari Parung, Ciampea, dan Gunung Sindur, Bogor, Jawa Barat. Sebanyak 347 isolat bakteri berhasil diisolasi, dan sebanyak 68 (19% isolat di antaranya mempunyai aktivitas AQS dengan empat isolat yang berpotensi sebagai bakteri AQS yaitu: TS 1 dan TS 2, TA 23, dan TY 33. Empat isolat tersebut teridentifikasi berdasarkan sekuen 16S rRNA sebagai Bacillus amyloliquefaciens, Lysinnibacillus sphaericus, Lysinnibacillus fusiformis, dan Bacillus cereus dengan persentase kemiripan masing-masing 93%, 99%, dan 100%. Berdasarkan analisa gen AHL (Acyl Homoserine Lactone laktonase (aiiA, keempat isolat tersebut menghasilkan enzim AHL. Hasil studi ini menunjukkan bahwa isolat bakteri hasil isolasi dari kolam ikan lele dumbo dapat menghambat mekanisme Quorum Sensing bakteri patogen ikan dengan mendegradasi autoinduser-nya yang berupa AHL.

  15. KAJIAN BAKTERI ENDOFIT PENGHASIL IAA (INDOLE ACETIC ACID UNTUK PERTUMBUHAN TANAMAN

    Directory of Open Access Journals (Sweden)

    Lina Herlina

    2016-10-01

    Full Text Available Bakteri Penghasil IAA mampu menghasilkan fitohormon yang dapat mempercepat pertumbuhan tanaman. Hormon IAA adalah auksin endogen yang berperan dalam pembesaran sel, menghambat pertumbuhan tunas samping, merangsang terjadinya absisi, berperan dalam pembentukkan jaringan xilem dan floem, dan juga berpengaruh terhadap perkembangan dan pemanjangan akar. Hormon IAA merupakan hormon yang berperan dalam pertumbuhan dan perkembangan tanaman sehingga sintesis oleh bakteri tertentu merupakan alasan yang menyebabkan peningkatan pertumbuhan tanaman. Oleh karena itu masalah yang perlu dikaji dalam penelitian ini adalah apakah isolat bakteri endofit dari tanaman kacang tanah berpotensi sebagai penghasil IAA , bagaimana identifikasi bakteri endofit yang mempunyai kemampuan menghasilkan IAA, bagaimana pengaruh IAA terhadap pertumbuhan tanaman kacang hijau. Secara khusus penelitian bertujuan untuk mendapatkan isolat bakteri endofit penghasil IAA pada tanaman kacang tanah , menguji kemampuan isolat bakteri endofit menghasilkan IAA secara in vitro dan menganalisis IAA terhadap pertumbuhan dan perkembangan tanaman kacang tanah . Pelaksanaan penelitian dilakukan dalam 3 tahap, pertama isolasi bakteri endofit penghasil IAA pada bagian akar dan batangdilakukan pada medium umum untuk pertumbuhan bakteri , kedua menguji kemampuan bakteri endofit memproduksi IAA secara in vitro, dilakukan dengan cara menumbuhkan bakteri pada media yang mengandung triptofan.dan ketiga introduksi bakteri endofit penghasil IAA pada tanaman kacang hijau. Pengujian kadar IAA yang dihasilkan diukur dengan menggunakan spektrofotometer dengan panjang gelombang 535 nm. Kecambah yang tumbuh diamati setelah empat hari . Parameter yang diamati adalah panjang kecambah , jumlah akar lateral. Hasil Isolasi didapat 16 isolat yang mempunyai kemampuan menghasilkan IAA dengan kadar yang di hasilkan berbeda dengan karakteristik morfologi yang berbeda. Isolat yang menghasilkan kadar IAA tinggi di aplikasi ke

  16. Fremtidens fødevareanalyser vil fokusere på bakteriers virulens-potentiale

    DEFF Research Database (Denmark)

    Olesen, Inger; Jespersen, Lene

    2010-01-01

    Hurtig og sikker identifikation af sygdomsfremkaldende bakterier i forurenede fødevarer er af stor betydning for fødevareindustrien. Imidlertid tyder ny forskning på, at det ikke er nok blot at identificere og kvantificere de sygdomsfremkaldende bakterier. Man skal derimod også ind og vurdere bak...

  17. PRODUKSI DAN APLIKASI PEPTON IKAN SELAR UNTUK MEDIA PERTUMBUHAN BAKTERI

    Directory of Open Access Journals (Sweden)

    dede - saputra

    2014-06-01

    Full Text Available Pepton adalah hidrolisat protein yang larut dalam air dan tidak menggumpal jika dipanaskan. Tujuan daristudi ini adalah untuk: 1 mengevaluasi potensi ikan selar sebagai bahan baku pepton ikan, 2 mengoptimasipenggunaan enzim terpilih, 3 mengarakterisasi pepton ikan selar, 4 membandingkan mutu pepton ikanselar dengan pepton komersial sebagai media pertumbuhan bakteri. Proses hidrolisis ikan selar fase postrigor dengan penambahan enzim papain 0,26% (b/v selama 6 jam. Analisis proksimat pepton ikan selar,menunjukkan kadar protein yang tinggi (74,17% basis basah dan mengandung beberapa jenis asam aminoessensial, yaitu histidina, isoleusina, leusina, lisina, metionina, fenilalanina, treonina, valina, tirosina, danarginina. Uji karakteristik pepton ikan menunjukkan bahwa kelarutan pepton ikan post rigor yaitu 96,74%,dengan total nitrogen 11,86%, α-amino nitrogen 1,07 g/100 g, α-amino nitrogen per total nitrogen 9,02; dankadar garam 0,41%. Nilai optical density bakteri ditumbuhkan pada media yang menggunakan pepton ikanlebih tinggi dibandingkan pertumbuhan bakteri pada media yang menggunakan pepton komersial.Kata kunci: asam amino, enzim, hidrolisis, pepton, post rigor

  18. Studi Bakteri Pembentuk Histamin Pada Ikan Kembung Peda Selama Proses Pengolahan

    Directory of Open Access Journals (Sweden)

    Ninoek Indriati

    2007-12-01

    Full Text Available Histamin merupakan salah satu senyawa biogenik amin yang dianggap sebagai penyebab utama keracunan makanan yang berasal dari ikan, terutama dari kelompok skombroid. Peda adalah produk fermentasi ikan yang umumnya dibuat dari ikan kembung yang merupakan kelompok ikan skombroid, yang diketahui banyak mengandung asam amino histidin bebas, sehingga potensial menimbulkan masalah keracunan histamin. Untuk mengetahui jenis‑jenis bakteri yang berperan pada pembentukan histamin pada ikan peda, telah diisolasi bakteri pembentuk histamin selama proses pengolahan peda, menggunakan media Niven yang sudah dimodifikasi. Isolat yang diperoleh diidentifikasi menggunakan BIOLOG Micro StationTm. Hasil penelitian menunjukkan terdapat 15 jenis bakteri pembentuk histamin pada bagian daging dan 11 jenis pada bagian isi perut. Selama proses fermentasi, saat histamin diproduksi secara intensif, bakteri pada ikan peda didominasi oleh Enterobacter spp. dan Staphylococcus spp. Enterobacter spp. sudah berada pada bahan baku, baik pada daging maupun pada isi perut, sedangkan Staphylococcus spp. merupakan bakteri yang mengkontaminasi selama proses pengolahan.

  19. Karakterisasi dan Deteksi Cepat Bakteri Penyebab Penyakit Darah pada Pisang

    Directory of Open Access Journals (Sweden)

    Nur Edy

    2011-07-01

    Full Text Available Blood disease of banana is one of the most serious banana disease in Indonesia. Although the disease has became the subject of quarantine it eventually spread and found in most provinces in Indonesia. The aim of this research were to identify the blood disease bacterium (BDB using morphological observation, biochemical assay, pathogenicity testing of hosts range using infectivity titration and rapid detection by Polymerase Chain Reaction (PCR. The results showed that the blood disease bacterium could be differentiated from Ralstonia solanacearum race 2, the causal agent of Moko disease and R. solanacearum tobacco isolates. BDB isolates were not able to hydrolyze gelatin, Tween 80, starch, and were not able to produce nitrite from nitrate. They were only able to produce acid from galactose and glycerol. The pathogenicity test indicated that the BDB was only able to infect the banana/plantain and was not able to infect tomato, eggplant, and chili. Rapid detection using PCR method showed that the 121F/R primers was able to amplify the BDB genome and was not able to amplify the genome of R. solanacearum tobacco isolates. Penyakit darah pada pisang masih merupakan kendala utama dalam budidaya pisang di Indonesia. Walaupun patogen penyakit darah sudah merupakan OPT karantina, namun saat ini penyakit sudah tersebar di seluruh provinsi di Indonesia. Penelitian ini bertujuan untuk mengidentifikasi bakteri penyebab penyakit darah dengan karakterisasi morfologi, biokimia, kisaran inang, dengan infectivity titration dan deteksi cepat menggunakan PCR. Hasil penelitian menunjukkan bahwa bakteri penyakit darah (BDB dapat dibedakan dengan Ralstonia solanacearum ras 2, penyebab penyakit Moko dan R. solanacearum isolat tembakau. Isolat BDB tidak dapat menghidrolisis gelatin, Tween 80, pati dan tidak dapat menghasilkan nitrit dari nitrat. Bakteri ini hanya menghasilkan asam dari galaktosa dan gliserol. Hasil uji patogenisitas menunjukkan bahwa bakteri penyakit

  20. AKTIVITAS ANTIMIKROBA YOGURT BERBASIS AIR KELAPA MENGHAMBAT BAKTERI PATOGEN SECARA IN VITRO

    Directory of Open Access Journals (Sweden)

    Lindawati S. A.

    2014-11-01

    Full Text Available Yogurt merupakan minuman susu yang difermentasi dengan menggunakan bakteri asam laktat Lactobacillus bulgaricus dan Streptococcus thermophyllus sebagai starter. Tujuan penelitian untuk mengetahui kemampuan tertinggi dari yogurt berbasis air kelapa dalam menghambat pertumbuhan bakteri pathogen (Salmonella, Staphylococcus, Klebsiela pneumonia dan E.coli secara in vitro. Penelitian ini menggunakan rancangan acak lengkap (RAL dengan empat perlakuan dan empat ulangan. Keempat perlakuan tersebut: Ko: susu skim 12%+air; K1: susu skim 12%+air kelapa gading; K2: susu skim 12%+kelapa gading bulan; K3: susu skim 12%+air kelapa hijau. Peubah yang diamati adalah aktivitas antimikroba yogurt terhadap bakteri pathogen (Salmonellatyphi, Staphylococcus, Klebsiella pneumonia dan E.coli, total plate count (TPC, total bakteri asam laktat dan E,coli. Hasil penelitian menunjukkan bahwa aktivitas antimikroba tertinggi diperoleh pada yogurt berbasis air kelapa bulan terhadap bakeri Salmonella typhi dan Staphylococcus masing-masing sebesar 0,21 dan 0,26 cm dengan total bakteri asam laktat1,1×107 cfu/mL sedangkan untuk Klebsiella pneumonia dan E.coli diperoleh pada yogurt berbasis air kelapa gading sebesar 0,38 dan 0,64 mm dengan total bakteri asam laktat 3,1×106 cfu/mL.Dari hasil penelitian dapat disimpulkan bahwa yogurt berbasis air kelapa gading, bulan, hijau dan tanpa air kelapa memiliki aktivitas antimikroba berspektrum luas (menghambat bakteri gram positif dan negatif.

  1. IDENTIFIKASI BAKTERI DARI IKAN TONGKOL (Euthynnus affinis YANG DIPERDAGANGKAN DI PASAR IKAN KEDONGANAN BALI

    Directory of Open Access Journals (Sweden)

    Gusti Ayu Dianti Violentina

    2016-06-01

    Full Text Available Ikan tongkol (Euthynnus affinis merupakan ikan konsumsi yang disukai masyarakat.Pengetahuan tentang bakteri yang ditemukan pada tubuh ikan ini sangat penting untuk tujuan kesehatan masyarakat dan kajian biologi ikan.  Penelitian ini bertujuan untuk mengidentifikasi bakteri yang berasosiasi dengan ikan tersebut.Bakteri dari usus ikan diambil secara aseptis dan ditumbuhkan pada Blood Agar dan Nutrient Broth. DNA total dari kultur agar cair diisolasi dengan chelax, gen 16S RNA diamplifikasi dengan PCR menggunakan primer universal dengan produk sekitar 1300 bp. Produk PCR dirunut dengan metode Big-Dye termination. Hasilnya disepadankan dan dianalisis dengan MEGA 6.0. Pada penelitian ini, 14 spesies bakteri yang memiliki > 99% kesamaan dengan data GenBankteridentifikasi, yaitu Photobacterium leiognathi, Uruburuella testudinis, Aeromonas molluscorum, Psychrobacter celer, Psychrobacer faecalis, Acinetobacter johnsonii, Vibrio gallicus, Bacillus megaterium, Vagococcus fessus, Shewanella baltica, Shewanella algae, Rothia nasimurium, Myroides phaeus dan Yersinia ruckeri. Peran bakteribakteri tersebut dalam biologi ikan dan kesehatan masyarakat perlu dikaji lebih lanjut.

  2. BIOAKTIFITAS MINYAK ATSIRI SEREH Cymbopogon citratus DC. TERHADAP PERTUMBUHAN BAKTERI Escherichia coli DAN Staphylococcus aureus

    OpenAIRE

    Rahman, Hasriani

    2013-01-01

    Penelitian ini mengenai bioaktifitas minyak atsiri sereh Cymbopogon citratus DC. terhadap pertumbuhan bakteri Escherichia coli dan Staphylococcus aureus. Penelitian ini bertujuan untuk mengetahui bioaktifitas dan sifat antibakteri minyak atsiri sereh Cymbopogon citratus DC. terhadap pertumbuhan bakteri Escherichia coli dan Staphylococcus aureus. Pengujian daya hambat dilakukan dengan metode difusi agar menggunakan 5 variasi konsentrasi 100%, 50%, 25%, 12,5% dan 6,25% b/v pada media MHA (Mull...

  3. IDENTIFIKASI DAN UJI POTENSI BAKTERI LIPOLITIK DARI LIMBAH SBE (SPENT BLEACHING EARTH SEBAGAI AGEN BIOREMEDIASI

    Directory of Open Access Journals (Sweden)

    Fitralia Elyza

    2016-03-01

    Full Text Available Limbah minyak kelapa sawit yang terbanyak adalah SBE (Spent Bleaching Earth, limbah ini mengandung residu minyak tinggi yang dapat mencemari lingkungan, 30% residu minyak pada limbah SBE dapat digunakan bakteri untuk pertumbuhannya, sehingga adanya bakteri mampu menjadi agen bioremediasi pencemaran SBE. Penelitian dilakukan untuk mendapatkan bakteri lipolitik sebagai agen potensial bioremediasi pada limbah SBE. Metode pengambilan sampel limbah SBE secara random sampling. Sampel tanah diambil secara acak dari beberapa titik area limbah SBE. Bakteri diisolasi dari sampel limbah SBE, kemudian dilakukan tahapan yaitu : pemurnian, seleksi, uji potensi, bakteri berpotensi mereduksi lipid dikarakterisasi dan diidentifikasi genusnya. Hasil penelitian menunjukkan bahwa Aktivitas enzim lipase yang tinggi menandakan bahwa bakteri lipolitik bekerja optimal merombak zat pencemar. Bakteri yang memiliki potensi sebagai agen bioremediasi terdiri dari genus Citrobacter (B1, Enterobacter (B2 dan Acinetobacter (B3. The most palm oil waste is SBE (Spent Bleaching Earth, this waste had many reduced lipid that got pollution for inviroments, Bacteria can use lipid from SBE as much as 30% for growed. So that consist of bacteria in SBE as a potensial agent for remediation. This study aims to obtain lipolytic bacteria as a potential agent of bioremediation. The method of sampling soil were taken at random from SBE waste, Bacteria were isolated from the SBE waste, then they were selected into steps : performed purification, selection, potential test, then characterized and identified it’s genus of potential bacteria. The results showed that the higest activity enzyme of lipolytic indicated that the lipolytic bacteria worked optimal for reduce polution. Bacteria had potential as a bioremediation agent consisting of genus Citrobacter (B1, Enterobacter (B2 and Acinetobacter (B3.

  4. PENGGUNAAN BAKTERI PROBIOTIK DENGAN KOMPOSISI BERBEDA UNTUK PERBAIKAN KUALITAS AIR DAN SINTASAN PASCALARVA UDANG WINDU

    Directory of Open Access Journals (Sweden)

    Muharijadi Atmomarsono

    2009-04-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui pengaruh komposisi jenis bakteri probiotik terhadap perbaikan kualitas air dan sintasan pascalarva udang windu pada skala laboratorium. Rancangan acak lengkap (RAL dengan menggunakan 24 akuarium yang masing-masing diisi 10 L air bersalinitas 28 ppt dan 200 ekor benur windu PL-15 telah diaplikasikan pada percobaan di Laboratorium Balai Riset Perikanan Budidaya Air Payau (BRPBAP Maros. Delapan perlakuan yang dicobakan adalah A Bakteri probiotik asal laut (BL536+BL542+BL548; B Bakteri asal mangrove (PK446+BR883+BR931+MY1112; C Bakteri probiotik asal tambak (MR55+BT950+BT951+PR1080+BN2067; D Bakteri laut+mangrove; E Bakteri laut+tambak; F Bakteri mangrove+tambak; G Bakteri laut+mangrove+tambak; H Kontrol (tanpa bakteri probiotik. Masing-masing perlakuan diulang tiga kali. Setelah 96 jam aplikasi didapatkan bahwa kombinasi bakteri probiotik asal mangrove dan tambak mampu mengendalikan kandungan bahan organik secara signifikan (P0,05. Walaupun konsentrasinya masih aman (0,0136—0,0184 mg/L, peningkatan kandungan nitrit kurang mampu dikendalikan oleh bakteri probiotik yang diaplikasikan (P>0,05. Sintasan pascalarva udang windu pada perlakuan bakteri probiotik asal laut (97,5% nyata lebih tinggi (P<0,05 daripada kontrol (82,0%. Secara keseluruhan, peningkatan populasi bakteri Vibrio spp. dalam air telah menyebabkan menurunnya sintasan pascalarva udang windu (r = -0,834; P<0,01. The objective of this study was to know the effect of different probiotic bacteria compositions on water quality improvement and survival rate of tiger shrimp postlarvae. This experiment was carried out in completely randomized design using 24 aquaria filled with 10 L of 28 ppt water and 200 pcs of tiger shrimp PL15 at the RICA laboratory. Eight treatments tested here were A Sea bacteria (BL536+BL542+BL548; B Mangrove bacteria (PK446+BR883+BR931+MY1112; C Brackishwater pond bacteria (MR55+BT950+BT951+PR1080+BN2067; D Bacteria of A+B; E

  5. Aktivitas Antimikroba Ekstrak Bubuk Buah Mengkudu (Morinda citrifolia L. Terhadap Pertumbuhan Bakteri Patogen

    Directory of Open Access Journals (Sweden)

    Nyoman Semadi Antara

    2015-04-01

    Full Text Available Penelitian yang dilakukan bertujuan untuk mengkaji aktivitas antimikroba ekstrak bubuk buah mengkudu (Morinda citrifolia L. terhadap pertumbuhan beberapa bakteri patogen. Bubuk buah mengkudu diolah dari buah mentah dan matang yang kemudian diekstrak menggunakan berbagai jenis larutan pengekstrak. Larutan pengekstrak yang dicoba dalam penelitian ini adalah etanol, petroleum eter (PE, dan aquades. Hasil percobaan menunjukkan bahwa ekstrak bubuk mengkudu mentah dan matang yang diekstraksi dengan pelarut etanol memperlihatkan spektrum penghambatan yang lebih luas dibandingkan dengan menggunakan larutan pengekstrak PE dan aquades. Ekstrak buah mengkudu yang menggunakan etanol sebagai larutan pengekstrak dapat menghambat pertumbuhan Escherichia coli, Salmonella typhi dan Bacillus cereus. Sementara ekstrak menggunakan pelarut PE hanya memberikan penghambatan terhadap B. cereus, dan ekstrak bubuk mengkudu yang diekstrak dengan aquades tidak terdeteksi memberikan penghambatan terhadap ketiga bakteri uji.Kata Kunci: antimikroba, mengkudu, larutan pengekstrak, bakteri pathogen.

  6. ISOLASI BAKTERI ENDOFIT DARI DAUN SIRIH (Piper betle L. SEBAGAI ANTIBAKTERI TERHADAP Escherichia coli DAN Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    desi - sagita

    2017-03-01

    Full Text Available Bakteri endofit adalah salah satu alternatif penghasil senyawa antimikroba. Keberadaan bakteri dalam tanaman memungkinkan bakteri menghasilkan senyawa bioaktif yang sama seperti yang terkandung dalam tanaman inangnya. Penelitian ini bertujuan untuk mengisolasi dan mengidentifikasi bakteri endofit yang memiliki kemampuan menghambat pertumbuhan bakteri lainnya. Aktifitas antibakteri diukur menggunakan metode Kirbi Bauer. Sirih (Piper bettle adalah tanaman yang telah digunakan oleh banyak orang karena mengandung senyawa yang baik untuk kesehatan. Jumlah bakteri endofit yang berhasil diisolasi adalah 13 isolat yaitu E1, E2, E3,E4,E7,E8, E9, E10, E11, E12 dan E13. Berdasarkan uji aktifitas antibakteri, 6 dari 13 isolat endofit yang berpotensi memberikan aktifitas antibakteri. 5 dari isolat tersebut yang mampu menghambat pertumbuhan bakteri Staphyl,ococcus aureus dan E8 yang aktifitas nya tinggi dengan diameter zona bening 18.96 mm dan hanya 1 isolat yaitu E7 yang mampu menghambat  Escherichia coli dengan diameter zona bening 14.01 mm.

  7. Pengaruh Lama Paparan Gelombang Ultrasonik Frekuensi Terapi terhadap Jumlah Koloni Bakteri Streptococcus mutans

    Directory of Open Access Journals (Sweden)

    F. Fransiska

    2016-10-01

    Full Text Available Latar Belakang. Gelombang Untrasonik telah digunakan untuk terapi dan diagnosis, di klinik kedokteran gigi popular digunakan untuk ultrasonik skaler. Efek termal dan nontermal gelombang ultrasonik dapat mempengaruhi lingkungan tumbuh bakteri, merusak enzim bakteri, dan struktur bakteri. Streptococcus mutans merupakan bakteri penyebab karies gigi. Tujuan penelitian. Penelitian ini bertujuan untuk mengetahui pengaruh lama paparan gelombang ultrasonik frekuensi terapi 3,5 MHz terhadap jumlah koloni bakteri Streptococcus mutans. Cara penelitian. Penelitian ini dilakukan pada 20 buah cawan petri yang berisi koloni bakteri streptococcus mutans dengan media agar darah. Dua puluh buah petri dibagi menjadi 4 kelompok yaitu kelompok kontrol (A dan kelompok perlakuan (B, C, D. kelompok perlakuan diaplikasi gelombang ultrasonik frekuensi 3,5MHz  selama 5, 10, dan 15 menit, sedangkan kelompok kontrol tidak diberi perlakuan apapun. Perhitungan jumlah koloni bakteri dilakukan dengan pengamatan menggunakan colony counter dengan standart plate count (SPC method. Hasil penelitian jumlah koloni bakteri Streptococcus mutans dianalisis menggunakan ANAVA satu jalur menunjukkan ada perbedaan yang signifikan (p<0,05 berarti terdapat pengaruh lama paparan gelombang ultrasonik frekuensi terapi 3,5 MHz terhadap jumlah koloni bakteri Streptococcus mutans. Hasil analisis post hoc (LSD terhadap jumlah koloni bakteri Streptococcus mutans juga menunjukkan ada perbedaan rerata antar kelompok perlawanan yang signifikan (p<0,05. Kesimpulan. Kesimpulan penelitian ini adalah lama paparan gelombang ultrasonik frekuensi terapi 3,5 MHz berpengaruh terhadap jumlah koloni bakteri Streptococcus mutans.    Introduction. Ultrasonic waves have been used for therapy and diagnosis, in dental clinic ultrasonic waves are used popular for ultrasonic scaler. Thermal and non thermal effects from ultrasonic wave influence the environment of bacteria disturb bacteria enzyme and the bacteria

  8. KARAKTERISASI ENZIM KITOSANASE DAR] ISOLAT BAKTERI KPU 2123 DAN APLIKASINYA UNTUK PRODUKS1 OLIGOMER KITOSAN

    Directory of Open Access Journals (Sweden)

    Yusro Nuri Fawzya

    2009-06-01

    Full Text Available Penelitian ini merupakan sebagian dari rangkaian penelitian mengenai eksplorasi enzim kitinolitik dari mikroba lingkungan laut, khususnya dari limbah udang. Tujuan penelitian ini adalah untuk mengidentifikasi isolat bakteri KPU 2123 dari limbah udang, mengkarakterisasi dan mengaplikasikan enzim kitosanase yang dihasilkan oleh bakteri tersebut untuk produksi oligomer kitosan dan menguji bioaktivitas oligomer kitosan tersebut sebagai antitumor dan antibakteri. Karakterisasi enzim dilakukan dengan menguji aktivitas enzim pada berbagai suhu dan pH. Selain itu juga ditentukan besarnya aktivitas yang tersisa setelah enzim diinkubasi pada suhu dan lama waktu tertentu. Pengaruh ion logam terhadap aktivitas enzim juga dilihat dengan mereaksikan enzim dengan 1 mM ion logam dalam bentuk larutan khlorida. Hasil penelitian menunjukkan bahwa berdasarkan analisis gen 16S-rRNA, isolat bakteri KPU 2123 memiliki kemiripan 95% dengan Stanotrophomonas maltophilia. Enzim kitosanase dari isolat ini bekerja optimal pada suhu 50 ºC dan pH 6. Enzim ini cukup stabil pada suhu 37 ºC selama 120 menit. Penambahan ion logam berpengaruh terhadap aktivitas enzim. Ion logam Zn²+ (sebagai garam klorida 1 mM menghambat 100% aktivitas enzim tersebut. Penggunaan enzim kitosanase dalam menghidrolisis substrat kitosan, menghasilkan oligomer kitosan yang mengandung tetramer, pentamer dan heksamer Oligor kitosan tersebut mampu menghambat pertumbuhan bakteri Staphylococcus aureus sebesar 10,06% dan dapat menyebabkan kematian sel HeLa dengan LC50 pada dosis 120 ppm.

  9. Seleksi dan Identifikasi Bakteri Selulolitik yang Dapat Mendegradasi Serat Kasar Daun Singkong

    Directory of Open Access Journals (Sweden)

    Mulyasari Mulyasari

    2015-12-01

    asal saluran pencernaan ikan gurame yaitu UG3, UG6, UG7, dan UG8 dengan mengukur aktivitas enzim selulase secara kuantitatif pada substrat Carboxy Methyl Cellulose (CMC dan daun singkong menggunakan metode 3,5-dinitrosalicylic acid (DNS. Identifikasi bakteri dilakukan pada 3 isolat yang memiliki aktivitas enzim selulase tertinggi pada substrat daun singkong berdasarkan morfologi (perwarnaan Gram, motilitas dan bentuk bakteri, uji biokimia (oksidase dan katalase dan analisis gen (16S-rRNA. Hasil penelitian menunjukkan bahwa dari 4 isolat yang diuji cobakan, isolat UG7 memiliki aktivitas enzim selulase (CMCase tertinggi (0,0043 U/ml sedangkan yang terendah adalah UG3 (0,0018 U/ml. Pada uji coba di substrat daun singkong, aktivitas enzim tertinggi terlihat pada isolat UG3 (0,107 U/ml dan terendah adalah UG6 (0,077 U/ml. Hasil identifikasi dari 3 jenis isolat bakteri uj i yang memiliki kemampuan mendegradasi daun singkong tertinggi (UG3, UG7, dan UG8 menunjukkan bahwa ketiga jenis isolat tersebut merupakan bakteri jenis Gram positif berbentuk batang (basil. Berdasarkan data base dari GenBank, isolat UG3 memiliki kemiripan sebesar 93% dengan Bacillus clausii, UG7 memiliki kemiripan sebesar 96% dengan Bacillus amyloliquefaciens dan UG8 memiliki kemiripan sebesar 88% dengan Bacillus subtilis.

  10. Eksplorasi Bakteri yang Berpotensi Sebagai Agens Pengendali Hayati Fusarium solani dan Meloidogyne incognita pada Lada

    Directory of Open Access Journals (Sweden)

    Citra Mayang Wardhika

    2014-12-01

    Full Text Available Indonesia is major producer of black pepper (Piper nigrum L., however the pepper production has been decreasing in the last decades. Black pepper yellowings caused by Fusarium solani and Meloidogyne incognita is one of the most important disease on pepper causing the decrease of pepper production. This research was aimed at the selection of potential bacteria as a biological control agents of F. solani and M. incognita on black pepper. The bacteria were isolated from rhizospheric soil of healthy plant. To determine the ability of biological agents, they were tested against F. solani and M. incognita. Seven isolates fluorescent pseudomonads, 19 isolates of Bacillus spp. and 21 bacterial isolates which were yet to be identified were isolated from soil rhizosphere. The results show that there are 5 antagonist bacterial isolates which were able to inhibit the growth of F. solani but so far no bacteria that caused cell lysis to M. incognita larvae was found.     Indonesia merupakan negara produsen lada yang pada beberapa waktu terakhir ini telah mengalami penurunan produksi. Penyakit kuning yang disebabkan oleh Fusarium solani dan Meloidogyne incognita merupakan salah satu penyebab terjadinya penurunan tersebut. Penelitian bertujuan untuk menyeleksi bakteri yang berpotensi sebagai pengendali hayati Fusarium solani dan Meloidogyne incognita pada lada. Isolasi bakteri dilakukan dari tanah rizosfer pertanaman lada sehat dan selanjutnya untuk mengetahui kemampuan agens hayati dilakukan uji antagonis terhadap F. solani dan M. incognita. Hasil isolasi dari rizosfer pertanaman didapatkan 7 isolat bakteri kelompok Pseudomonad fluoresen, 19 isolat bakteri Bacillus spp. dan 21 isolat bakteri yang belum diidentifikasi lebih lanjut. Hasil uji antagonis menunjukkan bahwa ada 5 isolat bakteri yang mampu menghambat pertumbuhan F. solani namun belum ditemukan adanya bakteri yang mampu menghambat pertumbuhan M. incognita.

  11. Penggunaan Bakteri Asam Laktat dan Lemak Sapi dalam Pengolahan Limbah Tuna menjadi Sosis Fermentasi

    Directory of Open Access Journals (Sweden)

    Diah Ikasari

    2011-12-01

    Full Text Available Penelitian penggunaan bakteri asam laktat dan lemak sapi dalam pengolahan sosis fermentasi ikan tuna telah dilakukan. Tetelan daging tuna dan lemak sapi yang masing-masing telah halus dicampur dengan konsentrasi lemak sapi 10 dan 20% dari bahan baku. Adonan daging dan lemak kemudian diaduk dengan bumbu dan bakteri asam laktat. Terdapat 3 macam perlakuan bakteri yang digunakan yaitu Lac tobac illus plantarum,  Lactobacillus fermentum,dan campuran keduanya. Setelah tercampur secara merata, adonan kemudian dicetak dalam casingplastik dan disimpan pada suhu 25oC selama 24 jam. Setelah 24 jam, sosis dikeringkan dengan dehumidifierpada suhu 25°C selama 2 jam. Kemudian sosis difermentasi pada suhu ruang selama 24 jam dan selanjutnya dikukus selama 45 menit. Pengamatan yang dilakukan adalah analisis organoleptik,  kandungan asam laktat, pH, analisis mikrobiologi (ALT, coliform, jumlah bakteri asam laktat, dan E. coli serta nilai gizi (kadar air, kadar abu, kadar lemak, dan kadar protein produk sosis fermentasi. Hasil penelitian menunjukkan bahwa perlakuan penambahan lemak 20% menghasilkan produk sosis ikan tuna fermentasi dengan penampakan dan bau lebih baik, menyebabkan peningkatan kandungan as am laktat dan penurunan pH produk bila dibandingkan dengan penambahan lemak 10%. Penggunaan jenis bakteri yang berbeda tidak berpengaruh pada nilai atribut dan tingkat kesukaan panelis, yaitu panelis menyatakan netral hingga agak suka terhadap produk sosis tuna fermentasi yang dihasilkan. Kandungan asam laktat yang diperoleh adalah 0,28–0,37% sedangkan pH sosis fermentasi yang diperoleh berkisar antara 5,28–6,02. Jumlah total bakteri pada sosis tuna fermentasi adalah log 2,53–3,33, sedangkan jumlah total bakteri asam laktat yang terkandung pada sosis tuna fermentasi adalah log 2,42–2,50. Adapun jumlah coliformrata-rata pada semua perlakuan adalah <3 MPN/g dan E. coli negatif, sedangkan kadar air sosis fermentasi yang dihasilkan adalah 54–58%; kadar

  12. Efek Antibakteri Ekstrak Daun Mimba (Azadirachta indica A. Juss terhadap Bakteri Vibrio algynoliticus Secara In Vitro

    Directory of Open Access Journals (Sweden)

    Uli Ayini

    2014-03-01

    Full Text Available Budidaya udang windu di Indonesia telah berkembang pesat. Salah satu kendala budidaya udang adalah penyakit Vibriosis yang disebabkan oleh bakteri Vibrio algynoliticus. Tujuan penelitian ini adalah untuk mengetahui efek antibakeri ekstrak daun mimba terhadap bakteri Vibrio algynoliticus. Penelitian ini menggunakan metode dilusi untuk mengetahui efek antibakteri ekstrak daun mimba terhadap bakteri Vibrio algynoliticus secara in vitro. Konsentrasi ekstrak yang digunakan (% yaitu: 0; 2,5; 5; 7,5; 10; 12,5 dan sebagai kontrol terdiri dari kontrol positif, dan kontrol negatif. Pengumpulan data untuk menentukan MIC (Minimum Inhibitory Concentration dilakukan dengan membandingkan kejernihan kultur di medium TSB 2% pada berbagai konsentrasi yang berbeda, dengan kontrol positif dan kontrol negatif. Penentuan MBC (Minimum Bacterisidal Concentration dilakukan dengan melihat ada tidaknya dan jumlah koloni bakteri Vibrio alginolyticus yang muncul pada medium subkultur TSA 2% setelah inkubasi 24 jam. Hasil penelitian menunjukkan nilai MIC yaitu konsentrasi 5%, hal ini ditunjukkan dengan tabung yang mulai jernih. Nilai MBC ekstrak daun mimba terhadap bakteri Vibrio alginolyticus adalah konsentrasi 12,5% ditandai dengan sudah tidak munculnya  koloni bakteri Vibrio alginolyticus. Berdasarkan penelitian ini dapat disimpulkan bahwa ekstrak daun mimba dapat memberikan efek antibakteri terhadap bakteri Vibrio alginolyticus secara in vitro.Tiger shrimp cultivation in Indonesia has been growing rapidly. The main obstacle is the shrimp farming vibriosis disease caused by the bacterium Vibrio algynoliticus. The aim of this research was to determine the effects of neem leaf extract antibakeri against Vibrio algynoliticus. This study used a dilution method to determine the antibacterial effect of neem leaf extract against Vibrio algynoliticus bacteria in vitro. The concentration of the extract used (%: 0; 2.5; 5; 7.5; 10; 12.5 and as a control consisting of a positive

  13. Uji Kemampuan Bakteri Azotobacter S8 dan Bacillus subtilis untuk Menyisihkan Trivalent Chromium (Cr3+ pada Limbah Cair

    Directory of Open Access Journals (Sweden)

    Muhammad Fauzul Imron

    2016-04-01

    Full Text Available Penggunaan kromium dalam berbagai industri telah menyebabkan pencemaran pada lingkungan. Limbah kromium yang sering ditemukan pada badan air dalam bentuk Cr3+ dan Cr6+. Bakteri diketahui mampu menyisihkan logam berat kromium sehingga dapat digunakan sebagai agen bioremediasi. Azotobacter S8 dan Bacillus subtilis merupakan bakteri yang mampu menyisihkan logam berat kromium. Tujuan dari penelitian ini adalah untuk menentukan komposisi optimum dan persentase penyisihan logam berat kromium oleh bakteri Azotobacter S8 dan Bacillus subtilis baik secara tunggal ataupun konsortium. Hasil penelitian ini menunjukkan bahwa persentase penyisihan tertinggi dilakukan oleh bakteri tunggal Azotobacter S8 yaitu 10,53% pada konsentrasi 50 mg/L dengan waktu 4 jam dan pH 8,35 serta jumlah koloni akhir yang terukur adalah 4 x 109 CFU/ml.

  14. Efek Pengunyahan Permen Karet Gula dan Xylitol terhadap Pertumbuhan Bakteri Streptococcus Mutans pada Plak Gigi

    Directory of Open Access Journals (Sweden)

    Volanda Kusumaningsari

    2011-06-01

    Full Text Available Latar Belakang. Manusia memiliki flora normal yang hidup di dalam tubuhnya. Salah satu flora normal di rongga mulut adalah bakteri Streptococcus mutans yang memiliki kaitan erat dengan insidensi karies. Sekarang banyak beredar produk permen karet di masyarakat yang mengandung gula dan xylitol. Tujuan. Penelitian ini bertujuan untuk mengetahui efek mengunyah permen karet gula dan xylitol terhadap pertumbuhan bakteri S. mutans pada plak gigi. Metode penelitian. Subjek penelitian berjumlah 15 orang dibagi menjadi 3 kelompok masing-masing 5 orang, yaitu mengunyah permen karet gula, xylitol dan buah ape I sebagai kontrol. Pengambilan plak dilakukan pada hari pertama sebelum diberi perlakuan (pre-tesQ dan hari keempat setelah diberi perlakuan (post-tesQ. Subjek diminta untuk melakukan scalling sebelum pengambilan data pre-test agar skor plak awal semua subjek nol. Subjek mengunyah 1 butir permen karet setelah makan atau 3 kali sehari selama 10 menit. Subjek tidak diperbolehkan makan dan minum selama 1 jam sebelum pengambilan data post-test. Plak ditanam dalam media agar TYCSB (tryptone-yeast-cysteine-sucrose-bacitracin lalu diinkubasi selama 72 jam pada kondisi anaerob dengan suhu 37°C. Penghitungan jumlah bakteri S. mutans dilakukan secara manual menggunakan counter. Analisis data dengan uji statistik Mann-Whitney. Hasil penelitian menunjukkan adanya peningkatan jumlah bakteri S. mutans pada plak gigi pada pengunyahan permen karet kandungan gula, sedangkan pengunyahan permen karet kandungan xylitol dapat menurunkan bermakna jumlah bakteri S. mutans. Kesimpulan. Pengunyahan perm en karet xylitol dapat menurunkan jumlah S. mutans pada plak gigi tetapi permen karet gula meningkatkan jumlah S. mutans.

  15. Aplikasi Isolat Bakteri Indigenous Ubi Kayu Karet (Manihot glaziovii pada Fermentasi Pembuatan Mocaf

    Directory of Open Access Journals (Sweden)

    K Kamsina

    2017-12-01

    Full Text Available Indigenous bacteria isolate of cassava rubber (Manihot glaziovii is an isolate of native bacteria which is available in rubber cassava tubers. Rubber cassava tuber is a cassava with a high content of cyanide acid (HCN. The study was aimed to see the ability of indigenous bacteria isolate of cassava cultivar rubber (BUG1 on mocaf making fermentation. This study used a completely randomized design with treatments (A addition of starter indigenous bacteria isolates of rubber variety (BUG1, (B without isolates, and (C without  fermentation. The resulting mocaf product was conducted a chemical tests consisted of moisture, ash, starch, acid degree, coarse fiber, and HCN content, while organoleptic tests consisted of color, aroma, and texture. The analysis results on the various treatments showed that the optimal treatment of mocaf flour produced was the addition of indigenous bacteria isolate starter of rubber variety (BUG1.ABSTRAKIsolat bakteri indigenous ubi kayu karet (Manihot glaziovii merupakan isolat bakteri asli yang berada dalam umbi ubi kayu karet. Ubi kayu kultivar  karet merupakan ubi kayu dengan kandungan asam sianida (HCN tinggi. Penelitian bertujuan untuk mempelajari kemampuan isolat bakteri indigenous ubi kayu kultivar karet (BUG1 pada fermentasi pembuatan mocaf. Penelitian ini menggunakan rancangan acak lengkap (RAL dengan perlakuan (A pemberian starter isolat bakteri indigenous varietas karet (BUG1, (B tanpa isolat, dan (C tanpa fermentasi. Terhadap produk mocaf  yang dihasilkan dilakukan uji kimia meliputi kadar air,  abu, pati, derajat asam, serat kasar, dan kadar HCN, sedangkan uji organoleptik meliputi warna, aroma, dan tekstur. Hasil analisis terhadap berbagai perlakuan menunjukkan perlakuan optimal untuk tepung mocaf  yang dihasilkan adalah pemberian starter isolat bakteri indigenous varietas karet (BUG1.

  16. Pembuatan Pasta Gigi Katekin Teh Hijau dan Uji Daya Hambat terhadap Bakteri Streptococcus Mutans dan Lactobascillus Ascidopillus

    OpenAIRE

    Fajriani Fajriani; Sartini Djide

    2015-01-01

    Pembuatan pasta gigi ini dilatar belakangi oleh keinginan peneliti agar memudahkan masyarakat menggunakan bahan alami katekin teh hijau yang hasilnya langsung di uji efektifitasnya terhadap daya hambat bakteri kariogenik. Penelitian ini bertujuan untuk melakukan pembuatan prodak pasta gigi katekin teh hijau dengan formula yang sesuai dengan hasil uji dan melakukan pengujian daya hambat pasta gigi katekin teh hijau terhadap bakteri streptococcus mutans dan lactobacillus acidophilus. Pembuatan ...

  17. Pembuatan Pasta Gigi Katekin Teh Hijau Dan Uji Daya Hambat Terhadap Bakteri Streptococcus Mutans Dan Lactobascillus Ascidopillus

    OpenAIRE

    Fajriani, Fajriani; Djide, Sartini

    2015-01-01

    Pembuatan pasta gigi ini dilatar belakangi oleh keinginan peneliti agar memudahkan masyarakat menggunakan bahan alami katekin teh hijau yang hasilnya langsung di uji efektifitasnya terhadap daya hambat bakteri kariogenik. Penelitian ini bertujuan untuk melakukan pembuatan prodak pasta gigi katekin teh hijau dengan formula yang sesuai dengan hasil uji dan melakukan pengujian daya hambat pasta gigi katekin teh hijau terhadap bakteri streptococcus mutans dan lactobacillus acidophilus. Pembuatan ...

  18. Seleksi Bakteri Antagonis Asal Rizosfer Tanaman Cabai (Capsicum sp) untuk Menekan Penyakit Layu Fusarium secara in vitro

    OpenAIRE

    Hilda Karim; Arifah Novia Arifin; A. Irma Suryani

    2016-01-01

    Tanaman cabai (Capsicum sp) merupakan salah satu komiditi yang memiliki nilai ekonomi tinggi yang rentan terserang penyakit layu yang disebabkan oleh cendawan F.o f.sp capsici . Penelitian ini bertujuan untuk memperoleh cendawan F.o f.sp capsici penyebab penyakit layu pada tanaman cabai yang sakit, untuk memperoleh isolat bakteri antagonis yang mampu menghambat perkembangan cendawan F.o f.sp capsici dan untuk mengetahui keefektifan bakteri antagonis dalam menghambat perkembangan cendawan F.o ...

  19. IDENTIFIKASI METABOLIT SEKUNDER DAN AKTIVITAS ANTIBAKTERI EKSTRAK DAUN SUNGKAI (Peronema canescens JACK. TERHADAP BEBERAPA BAKTERI PATOGEN

    Directory of Open Access Journals (Sweden)

    Arsyik Ibrahim

    2012-12-01

    Full Text Available A research which identification of secondary metabolites and antibacterial activity test from methanol exstract of leaf Sungkai (Peronema canencens Jack to several pathogens bacterial, which aims to identification of secondary methabolites and determine the antibacterial activity from crude methanol extract of leaf Sungkai (P. canencens Jack. against Streptococcus mutans, Salmonella thyposa, Bacillus subtilis and Staphylococcus aureus bacteria. Material test obtained by maceration with methanol, then tested for activity. Minimum Inhibition Concentration (MIC value extract was determined by liquid dilution and the followed by scratches on solid media method.  Minimum Kill Concentration (KBM value extracts was determined by agar diffusion method with using paper disks.The results secondary metabolite identify form extracts of leaves P. canencens obtainable derived alkaloid, terpenoids - steroids, flavonoids, and tannin compounds. Methanol extract have the antibacterial activity. Minimum Inhibition Concentration (MIC value of extract is concentration of 20% for bacteria S. mutans, S.thiposa and S.aureus, while for the B. subtilis is konsentration of 15%. Minimum Kill Concentration (KBM values exstract at a concentration of 5% effective at killing S. mutans and S. thyposa bacteria, while the concentration of 1% effective to bacteria B.subtilis and S.aureus. Key words: P. canencens Jack,  antibacteria activity, S. mutans, S. thiposa, B. subtillis, S. aureus   ABSTRAK   Telah dilakukan penelitian identifikasi metabolit sekunder dan aktivitas antibakteri ekstrak metanol daun Sungkai (P.canencens Jack terhadap beberapa bakteri patogen. Penelitian ini bertujuan untuk mengidentifikasi metabolit sekunder dan mengetahui aktifitas antibakteri dan Kadar Hambat Minimum (KHM dan Nilai Kadar Bunuh Minimum (KBM ekstrak kasar metanol daun Sungkai (P.canencens Jack. terhadap bakteri  Streptococcus mutans, Salmonella thyposa, Bacillus subtilis dan

  20. Transformasi α-Pinena dengan Bakteri Pseudomonas aeruginosa ATCC 25923

    Directory of Open Access Journals (Sweden)

    Nanik Wijayati

    2014-03-01

    Full Text Available Indonesia adalah Negara utama yang memproduksi minyak atsiri di dunia. Minyak terpentin adalah minyak atsiri yang dihasilkan dari destilasi getah pinus Pinus merkusi J ungh. Et. De. Vr. Tujuan penelitian ini adalah untuk meningkatkan nilai minyak terpentin dengan mengubah kandungan utamanya, α-pinena menjadi senyawa baru menggunakan P. Aeruginosa dalam metode mikrobiologi. Minyak terpentin diambil dari Perhutani Laboratorium Jawa Tengah, dibuat dengan seri konsentrasi 0,5%, 1%, 2%, dan 4%. Minyak terpentin diinokulasi dalam suspensi P. areuginosa selama 48 jam pada suhu kamar (25-28oC. Hasilnya diekstraksi menggunakan dietil eter. Filtrat Terpentin dianalisis menggunakan GCdan IR. Hasil analisis GC menunjukkan puncak baru di konsentrasi 0,5%, 1%, dan 2%, tetapi dalam konsentrasi 4% tidak menunjukkan puncak baru. Hasil IR menunjukkan hidroksil (OH- dan C-O alkohol. Berdasarkan penelitian ini, dapat disimpulkan bahwa minyak terpentin dapat ditransformasi untuk menjadi senyawa yang mengandung gugus-OH melalui metode mikrobiologi dengan menggunakan bakteri P. aeruginosa. Indonesia is the main producer of essential oil in the world. Turpentine oil is an essential oil which is obtained from pine resin distillation of Pinus merkusi Jungh. et. De.Vr. The aim of this experiment was to increase the value of turpentine oil by changing its main content, i.e. α-pinene, into a new compound using P. aeruginosa in microbiological method. Turpentine oil was collected from Perhutani Central Java Laboratory, and was made into 0.5%; 1%; 2%; and 4% concentrations and it was inoculated in P. areuginosa suspension for 48 hours in room temperature (25°C-280C. The result was extracted using diethylether. The filtrate of turpentine was analyzed using GC and IR. The GC analysis result showed a new peak in 0.5%; 1%; and 2% concentrations, but in the 4% concentration didn’t show a new peak. The IR result showed alcohol with hydroxyl (-OH and –C–O groups. This

  1. PENGARUH KOMBINASI JENIS BAKTERI PROBIOTIK BERBEDA TERHADAP SINTASAN DAN PRODUKSI UDANG WINDU DI TAMBAK SEMI-INTENSIF

    Directory of Open Access Journals (Sweden)

    Endang Susianingsih

    2012-12-01

    Full Text Available Penelitian dilaksanakan selama 16 minggu bertujuan untuk mengetahui pengaruh kombinasi bakteri probiotik berbeda terhadap sintasan dan produksi udang windu di tambak semi-intensif dengan padat penebaran tokolan 10 ekor/m2. Tiga kombinasi bakteri probiotik yang diuji adalah: A Kombinasi bakteri probiotik A (BL542+ MR55+BT951; B Pergiliran bakteri probiotik BL542 pada bulan I, MR55 bulan II, BT951 bulan III, dan BL542 bulan IV; dan (C Pergiliran bakteri probiotik BT951 pada bulan I, MY1112 bulan II, BL542 bulan III, dan BT951 bulan IV. Masing-masing perlakuan diulang tiga kali dalam Rancangan Acak Lengkap (RAL. Penelitian menggunakan 9 petak tambak di Instalasi Tambak Percobaan (ITP Marana, Maros yang berukuran 25 m x 10 m, yang masing-masing diaerasi dengan blower supercharge. Hasil penelitian menunjukkan, bahwa sintasan dan produksi udang windu tertinggi dicapai pada perlakuan probiotik C (76,6% dan 484,5 kg/ha, diikuti perlakuan probiotik B (56,2% dan 440,0 kg/ha, dan probiotik A (58,8% dan 320,8 kg/ha, namun secara statistik ketiga perlakuan ini berbeda tidak nyata (P>0,05. Relatif tingginya sintasan udang windu pada penelitian ini terkait dengan kemampuan bakteri probiotik dalam menekan jumlah bakteri Vibrio spp., kandungan Total Ammonium Nitrogen (TAN dan nitrit-nitrogen air tambak.

  2. Resistensi dan Sensitivitas Bakteri terhadap Antibiotik di RSU dr. Soedarso Pontianak Tahun 2011-2013

    Directory of Open Access Journals (Sweden)

    Nurmala Nurmala

    2015-09-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Salah satu upaya untuk mengurangi resistensi, pemberian antibiotik harus berdasarkan pola bakteri penyebab infeksi dan kepekaan bakteri terhadap antibiotik. Tujuan penelitian ini untukmengetahui pola bakteri, resistensi dan sensitivitasnya terhadap antibiotik di RSU dr. SoedarsoPontianak tahun 2011-2013. Penelitian deskriptif dengan pendekatan retrospektif dilakukan RSU dr. Soedarso, Pontianak. Sampel penelitian adalah hasil pemeriksaan kultur dan uji kepekaan spesimen pus pasien yang diperiksa di Bagian Mikrobiologi Unit Labolatorium Kesehatan (ULK. Dari 111 sampel,terdapat 21 jenis bakteri. Bakteri gram-negatif lebih banyak dari gram-positif, yaitu 70,7% dan 29,3%.Tiga bakteri terbanyak adalah Citrobacter freundii (18%, P. aeruginosa (17,1% dan Staphylococcusepidermidis (15,3%. Resistensi tertinggi bakteri adalah terhadap metronidazol (96,4%, sefaleksin(95,8%, sefuroksim (92,2%, oksasilin (91,7% dan sefadroksil (91,5% dan sensitivitas tertinggibakteri terhadap piperasilin/tozobaktam (89,7%, meropenem (82,9%, imepenem (78,1%, amikasin(76,3%, fosfomisin/trometamol (59,5% dan levofloksasin (56,1%. Kata kunci: bakteri, antibiotik, resistensi, sensitivitas, pus. Resistance and Sensitivity of Bacteria to Antibioticsat dr. Soedarso Hospital Pontianak 2011-2013 Abstract An effort to reduce resistance, antibiotics prescription should be based on information about pattern of bacteria and  sensitivity to antibiotics. The aim of the study is to  determine the patternof bacteria, resistance and sensitivity to antibiotics at dr. Soedarso Hospital Pontianak 2011-2013. This research is a descriptive study with retrospective approach. Samples were culture and sensitivity test result in pus specimen of dr. Soedarso Hospital patient’s examined at ULK. Thenumber of samples in this study were 111 samples. There were 21 type of bacterias. Gram-negativebacterias were found more than gram

  3. PERAN PEMERINTAH DALAM PENANGGULANGAN PENCEMARAN AIR TANAH OLEH BAKTERI E. COLI DI KOTA YOGYAKARTA

    Directory of Open Access Journals (Sweden)

    Fajar Winarni

    2014-03-01

    Full Text Available This study is an empirical legal research that uses primary and secondary data. The result of this  study is to be used f or the handling of  E.  coli  contamination where it  is the government ’s role to procure chlorine diffusers and monitor the quality of drinking water. The high level of contamination caused by the E. coli bacteria is due to the poor sanitation system and the close proximity of wells to septic tanks. Meanwhile, other constraints faced by the government include the lackof routine monitoring, lack of sanitation workers, and lack of proper implementation of the standardtechnical guidance on Procedures Planning Septic Tank with Absorption Systems. Penelitian ini merupakan penelitian hukum empiris yang menggunakan data primer dan sekunder. Hasil penelitian ini adalah dalam rangka penanggulangan pencemaran bakteri E. coli dimana Pemerintahberperan dalam pengadaan alat chlorine diffuser, sosialisasi hidup bersih, pengawasan kualitas air minum, dan sebagainya. Tingginya pencemaran bakteri E. coli dikarenakan sistem sanitasi yang buruk, dan jarakyang dekat antara sumur dengan saluran septic tank. Sementara itu kendala yang dihadapi antara lainPemerintah tidak melakukan pengawasan secara rutin, terbatasnya petugas sanitasi, tidak dilaksanakannyapetunjuk teknis SNI tentang Tata Cara Perencanaan Tangki Septik dengan Sistem Resapan.Kata Kunci: peran pemerintah, pencemaran, bakteri E. coli.

  4. Angka Lempeng Total Bakteri pada Broiler Asal Swalayan di Denpasar dan Kabupaten Badung

    Directory of Open Access Journals (Sweden)

    Magfirah Syahruddin

    2014-05-01

    Full Text Available Penelitian menggunakan Rancangan Acak Kelompok (RAK ini dilakukan untuk mengetahui nilai Angka lempeng Total Bakteri (ALTB pada daging broiler yang dijual di tiga swalayan wilayah Denpasar (S2 dan S3 dan Kabupaten Badung (S1. Metode penanaman bakteri yang digunakan dalam penelitian ini yaitu metode tuang. Sebanyak 1 ml larutan sampel yang telah diencerkan dimasukkan kedalam cawan petri. Kemudian ke dalam cawan tersebut dituangkan nutrient agar steril sampai media padat, diinkubasi dan dilakukan perhitungan bakteri yang tumbuh. Hasil penelitian ini menunjukkan rataan nilai ALTB pada swalayan S1, S2 dan S3 berturut- turut adalah 6,90x106 CFU/gr; 5,33x106 CFU/gr dan 7,50x106 CFU/gr. Dari hasil ini dapat disimpulkan bahwa ALTB broiler pada ketiga swalayan tidak bebeda nyata dan secara statistik nilai ALTB pada masing- masing swalayan lebih tinggi dari Standar Nasional Indonesia 1,00x106 CFU/gr (p< 0,01.

  5. Pemanfaatan Serbuk Gergaji Menjadi Biobutanol dengan Hidrolisis Selulase dan Fermentasi Bakteri Clostridium Acetobutylicum

    Directory of Open Access Journals (Sweden)

    Hayuni Devina Fajariah

    2014-09-01

    Full Text Available Biobutanol adalah jenis alkohol ikatan C-4 (C4H9OH yang terbuat dari biomassa. Penelitian ini dilakukan dengan memanfaatkan limbah kayu yang dihasilkan dari proses penggergajian kayu yang mengandung selulosa (55%, hemiselulosa (14%, dan lignin (21%. Biobutanol diproduksi dengan cara hidrolisis enzim selulase dan fermentasi bakteri Clostridium acetobutylicum. Variabel pada penelitian ini adalah penambahan enzim selulase pada proses hidrolisis (penambahan enzim atau tanpa penambahan enzim, pH awal proses fermentasi (5 atau 7 dan jumlah penambahan starter bakteri Clostridium acetobutylicum (5 atau 10 ml dengan variasi lama proses fermentasi 2,4,6,8,10,12 hari. Parameter dalam penelitian ini adalah analisa kadar selulosa, gula tereduksi, dan kadar butanol. Berdasarkan hasil penetian, diketahui bahwa proses hidrolisis dengan penambahan enzim selulase, kondisi awal fermentasi pH 5 dan penambahan inokulum bakteri Clostridium acetobutylicum sebanyak 10 ml dengan lama waktu fermentasi 12 hari merupakan kondisi yang paling efektif menghasilkan kadar butanol tertinggi dari 50 gram limbah serbuk gergaji. Kadar butanol tertinggi sebesar 1,88 % dari 1 µL sampel hasil fermentasi yang diinjeksikan ke dalam kromatografi gas.

  6. ISOLASI, SELEKSI, DAN IDENTIFIKASI BAKTERI DARI SALURAN PENCERNAAN IKAN LELE SEBAGAI KANDIDAT PROBIOTIK

    Directory of Open Access Journals (Sweden)

    Titin Kurniasih

    2013-08-01

    Full Text Available Penambahan probiotik pada pakan telah banyak diaplikasikan pada kegiatan akuakultur dan terbukti bermanfaat meningkatkan pertumbuhan dan efisiensi pakan ikan. Probiotik yang ditujukan untuk membantu meningkatkan aktivitas pencernaan dalam saluran pencernaan ikan, akan lebih baik apabila diisolasi dari saluran pencernaan ikan itu sendiri. Penelitian ini bertujuan untuk mendapatkan bakteri probiotik dari saluran pencernaan ikan lele, mengisolasi, menyeleksi, serta mengidentifikasi bakteri yang didapatkan. Lambung dan usus lele, digerus dan diencerkan, kemudian dikultur dengan teknik cawan sebar. Koloni yang didapat dimurnikan dan diseleksi dengan uji zona hidrolisis protein dan uji patogenisitas, dan diidentifikasi secara biokimiawi dan molekuler. Tahap isolasi mendapatkan 10 isolat, tahap uji zona hidrolisis protein mendapatkan 4 isolat dengan zona hidrolisis tertinggi, sedangkan uji patogenisitas hanya meloloskan 2 isolat, yaitu A1 dan L1. Hasil uji identifikasi biokimiawi dan molekuler menunjukkan bahwa isolat A1 adalah Staphylococcus epidermidis dan L1 adalah Bacillus cereus. Bacillus cereus merupakan spesies yang sebagian besar anggotanya merupakan probiotik bagi hewan darat dan ikan, dengan demikian dari penelitian ini didapatkan bahwa Bacillus cereus merupakan kandidat bakteri yang berpeluang untuk dijadikan probiotik.

  7. Efektifitas Jahe Merah (Zingiber officinale Var. Rubrum sebagai Additif Pakan dan Antimikrobia terhadap Pertumbuhan Bakteri Anaerob dan Coliform Secara In Vivo pada Ayam Pedaging

    Directory of Open Access Journals (Sweden)

    J.R. Manullang

    2015-10-01

    Full Text Available Jahe merah (Zingiber officinale Var. Rubrum dikenal sebagai bakteriasida. Penelitian ini bertujuan untuk mengetahui aktivitas antibakterial bubuk jahe terhadap pertumbuhan bakteri anaerob dan coliform (Escherichia coli dan Salmonella sp. secara in vivo pada Broiler. Penelitian ini menggunakan dua puluh empat DOC dengan berat badan 40,7 g. Pemberian bubuk jahe diberikan pada Broiler selama 5 hari dengan konsentrasi ekstrak jahe merah yaitu, 0,5, 1, dan 1,5% per kg pakan. Peubah yang diamati adalah berat badan, asupan pakan dan koloni bakteri. Hasil penelitian menunjukkan terdapat pengaruh ekstrak jahe merah pada total koloni bakteri yang cenderung menurun dengan semakin tinggi konsentrasi ekstrak jahe merah, semakin tinggi efek hambatan pertumbuhan bakteri. Dapat disimpulkan bahwa ekstrak jahe merah memiliki sejumlah aktivitas antibakteri untuk pertumbuhan bakteri anaerob dan coliform (E. coli dan Salmonella sp..

  8. PENGARUH RASIO BAKTERI PROBIOTIK TERHADAP PERUBAHAN KUALITAS AIR DAN SINTASAN UDANG WINDU,Penaeus monodon DALAM AKUARIUM

    Directory of Open Access Journals (Sweden)

    Muliani Muliani

    2016-12-01

    Full Text Available Penelitian bertujuan untuk mengetahui pengaruh rasio bakteri probiotik terhadap perubahan kualitas air dan sintasan pascalarva udang windu. Penelitian ini dilaksanakan di laboratorium basah Balai Riset Perikanan Budidaya Air Payau, Maros menggunakan akuarium dengan ukuran 40 cm x 30 cm x 27 cm yang diisi tanah tambak setebal 10 cm dan air tambak salinitas 28 ppt sebanyak 15 L serta pascalarva udang windu 30 ekor. Bakteri probiotik yang digunakan pada percobaan ini diisolasi dari air laut, daun mangrove, dan tambak. Pengamatan parameter kualitas air yang meliputi; BOT, NO2-N, PO4-P, NH4-N, total bakteri, dan total vibrio dilakukan pada awal penelitian dan selanjutnya 1 kali dalam setiap dua minggu, kecuali H2S yang diamati sekali dalam sebulan. Sedangkan sintasan udang windu diamati pada akhir penelitian. Hasil penelitian menunjukkan bahwa konsentrasi BOT, NO2-N, PO4-P, NH4-N, dan H2S mengalami fluktuasi dari awal hingga akhir penelitian pada semua perlakuan. Total bakteri terendah pada perlakuan L (bakteri laut 102 cfu/mL + bakteri mangrove 102 cfu/mL + bakteri tambak 102 cfu/mL, sedangkan total vibrio terendah pada perlakuan O (bakteri laut 104 cfu/mL + bakteri mangrove 104 cfu/mL + bakteri tambak 104 cfu/ mL. Hasil analisis statistik menunjukkan bahwa sintasan udang windu tidak berbeda nyata (P>0,05 pada semua perlakuan. The experiment aimed to determine the effect of ratio of probiotic bacteria on changes of water quality and survival rate of tiger shrimp Penaeus monodon in tanks. This experiment conducted in Research Institute for Coastal Aquaculture web laboratory used aquarium with 40 cm x 30 cm x 27 cm in size. Each aquarium filled with pond sediment (10 cm, pond water 15 L (28 ppt, and 30 pcs of tiger shrimp postlarvae. Probiotic bacteria used in this study were isolated from sea water, mangrove leaf, and ponds. Water qualities; TOM, PO4-P, NO2-N, and NH4-N were observed be weekly while H2S was observed once in a month. Survival rate of

  9. Penggunaan Aksis Jantung Pisang untuk Penyediaan Sumber Eksplan Bebas Bakteri

    OpenAIRE

    Roostika, Ika; Supriyati, Yati; Sutanto, Agus

    2015-01-01

    The sterile culture is very important in cryopreservation works. Bacterial-free explant sources are difficult to obtain during invitro culture of banana. Floral bud is expected as bacterial-free explant sources because the organ emerges above the groundand protected by bracts. The purposes of this study are to obtain optimal concentration of BA to regenerate male bud floralaxis explants of Barangan variety and to prove that cultures derived from these explants were free from bacterialcontamin...

  10. EFEK ANTIBAKTERI EKSTRAK KULIT BUAH DELIMA (Punica granatum L. TERHADAP BAKTERI PENYEBAB DIARE SECARA IN VITRO DAN UJI TOKSISITAS AKUT

    Directory of Open Access Journals (Sweden)

    Dian Sundari

    2012-10-01

    Full Text Available Telah dilakukan Penelitian efek antibakteri ekstrak alkohol 70% kulit buah delima (Punica granatum L terhadap bakteri Salmonell typhi, Escherichia coli, Shigella dysenteriae dan Vibro cholerae secara in vitro. Pengujian dilakukan menggunakan metode difusi dengan cakram kertas. Sebagai pembanding positif digunakan klorafenikol dan tetrasiklin, sedangkan akuades sebagai pembanding negatif. Selain itu, untuk mengetahui keamanan bahan, dilakukan uji toksisitas akut (LD50-nya pada hewan coba mencit dengan cara Weil C.S.Dari hasil penelitian, diketahui ekstrak kulit buah delima mempunyai efek antibakteri, ini terlihat dari konsentrasi yang dicoba (8,6; 34,4; 137,6; mmg/ml terdapat zona (daerah bening bekas bakteri pada lempeng agar yang ditanami bakteri Salmonella typhi dan Vibrio cholerae. Makin besar dosis yang diberikan, makin besar bebas bakterinya. Dari uji toksisitas akut, ternyata bahan termasuk golongan Moderatel toxic.

  11. POTENSI BAKTERI ENDOFITIK DARI TANAMAN KELADI TIKUS SEBAGAI PENGHASIL ZAT ANTIMIKROBA DAN ANTIOKSIDAN

    Directory of Open Access Journals (Sweden)

    Harmastini Sukiman

    2016-06-01

    Full Text Available Typhonium flagelliforme (Lodd. known as a medicinal plant to cure generative disease such as cancer. This research is focusing on isolation of endophytes bacteria from Typhonium flagelliforme (Lodd.. Twenty six of endophytes bacteria have been successfully isolated. Results indicated that nine isolates of bacteria could inhibit the growth of Bacillus subtilis and three isolates could inhibit Staphylococus aureus. The strongest secretion showed by KTD4 was 3.029 for Bacillus subtilis and KTBt1 2.042 for Staphylococcus aureus. Antioxidant activity tests of four selected isolates showed that KTBt4 could produce highest inhibition percentage up to 74.68% and IC50 68.103 ppm compared to vitamin C which is just 3.053 ppm.Keywords: antioxidant, endophyte, Typhonium flagelliforme (Lodd. ABSTRAKKeladi tikus atau Typhonium flagelliforme (Lodd. dikenal sebagai tanaman obat yang dapat menyembuhkan berbagai penyakit, khususnya kanker. Penelitian ini difokuskan untuk mengisolasi bakteri endofitik tanaman keladi tikus. Sebanyak 26 isolat bakteri berhasil diisolasi. Hasil uji menunjukkan bahwa 9 isolat bakteri dapat menghambat pertumbuhan Bacillus subtilis dan 3 isolat terhadap Staphylococcus aures. Kekuatan sekresi tertinggi dihasilkan oleh isolat KTD4 (bagian daun yang mencapai 3,029 untuk Bacillus subtilis dan KTBt1 (bagian batang 2,042 untuk Staphylococcus aureus. Uji aktivitas antioksidan dilakukan terhadap empat isolat terpilih menunjukkan bahwa isolat KTBt4 (bagian batang memberikan presentasi nilai inhibisi tertinggi yakni 74,68% dan nilai IC50 68,103 bpj dibandingkan dengan vitamin C yang mencapai 3,053 bpj.Kata kunci: antioksidan, endofit, keladi tikus

  12. ISOLASI DAN KARAKTERISASI BAKTERI TANAH SAWAH DI DESA SUKAWALI DAN DESA BELIMBING, KABUPATEN TANGERANG

    Directory of Open Access Journals (Sweden)

    Arief Pambudi

    2017-08-01

    Full Text Available Abstrak Penggunaan pupuk kimia secara berlebih dapat menyebabkan kerusakan tanah dan menyebabkan ekosistem yang ada didalamnya terganggu. Plant growth-promoting rhizobacteria (PGPR adalah bakteri yang hidup di daerah rizosfer tanaman yang dapat berperan sebagai biofertilizer, biostimulan dan bioprotektan. Penelitian ini bertujuan untuk memperoleh dan mengetahui karakteristik bakteri tanah yang berasal dari dua area persawahan, lokasi pertama di Desa Sukawali (TGR 1 dan lokasi kedua di Desa Belimbing (TGR 2, Kabupaten Tangerang. Penelitian dilakukan dengan mengambil sampel tanah, kemudian sampel dikultur dalam media agar nutrien dengan pengenceran bertingkat. Total bakteri dihitung dan isolat yang diperoleh diuji kemampuan dan karakternya dalam menambat nitrogen (BPN, melarutkan fosfat (BPF, menghasilkan indole acetic acid (IAA, menghasilkan Hidrogen Cyanide (HCN, aktivitas katalase, jenis Gram dan karakter motilitas. Total bakteri yang dapat tumbuh dari kedua lokasi sebanyak 2,4x106 CFU/g dan 1,8x106 CFU/g. Kedua lokasi diperoleh total 45 isolat dengan seluruhnya positif BPN, 42 isolat positif BPF, 24 isolat menghasilkan IAA, 27 isolat menghasilkan HCN, 43 isolat katalase positif, 39 isolat Gram positif, 6 isolat Gram negatif, serta 41 isolat motil. Berdasarkan uji yang dilakukan, terdapat 16 isolat yang berpotensi sebagai pupuk hayati.  Abstract Excessive use of chemical fertilizer may cause soil damage and disturb the ecosystem. Plant growth-promoting rhizobacteria (PGPR is a consortium bacteria that live in plant rhizosphere which acts as biofertilizer, biostimulant, and bioprotectant. The objective of this research is to isolate and investigate the characteristics of soil bacteria originating from two rice fields in Sukawali Village (TGR 1 and Belimbing Village (TGR 2, Tangerang Regency. The research was conducted by collecting soil samples and then culturing the bacteria onto nutrient agar medium with serial dilution. The total bacteria

  13. Perbedaan Daya Hambat Bakteri dari Propolis Cair yang Ada di Pasaran Terhadap Escherichia Coli dan Staphylococcus Aureus Secara In Vitro

    OpenAIRE

    Bangun Azhari Yusuf; Aziz Djamal; Asterina ,

    2015-01-01

    Abstrak Propolis adalah zat yang digunakan lebah melindungi sarangnya dari berbagai ancaman. Komponen utama propolis adalah resin yang dikumpulkan lebah dan dicampur dengan air liurnya. Manusia juga menggunakan propolis sebagai obat berbagai penyakit, seperti infeksi bakteri. Propolis memiliki kemampuan antibakteri terhadap Escherichiacoli dan Staphylococcus aureus. Kualitas dan jenis propolis sesuai dengan komposisi kimia, iklim dan tempat berkembang biak. Tujuan penelitian ini adalah meliha...

  14. ISOLASI DAN IDENTIFIKASI BAKTERI ASAM LAKTAT PENGHASIL INHIBITOR ENZIM HMG-KoA REDUKTASE DARI BEKASAM SEBAGAI AGEN PEREDUKSI KOLESTEROL

    Directory of Open Access Journals (Sweden)

    Rinto Rinto

    2015-10-01

    terhadap 5 isolat menghasilkan 2 bakteri yang mempunyai kemampuan penghambatan terhadap aktivitas enzim ¸Â•ÝWtu Lactobacillus acidophilus dan Lactobacillus delbruckii sp. delbruckii dengan kemampuan penghambatan  berturut-turut adalah 66,67% dan 58,33%. Kata kunci: L. acidophilus, L. delbrucki, inhibitor HMGR, kolesterol, bekasam

  15. PENGGUNAAN MEMBRAN KERAMIK UNTUK MENURUNKAN BAKTERI E. COLI DAN TOTAL SUSPENDED SOLID (TSS PADA AIR PERMUKAAN

    Directory of Open Access Journals (Sweden)

    Ir kasam

    2015-10-01

    Full Text Available digunakan sebagai air minum. Adapun parameter yang cukup tinggi pada air permukaan adalah bakteri E. Coli dan Total Suspended Solid (TSS. Salah satu alternative pengolahan untuk parameter bakteri E. Coli dan TSS adalah dengan filtrasi dengan membran filter. Membran keramik adalah salah satu alat yang bisa digunakan sebagai filter pada air permukaan. Penelitian ini bertujuan untuk mengetahui kinerja membran keramik dalam menurunkan E.Coli dan TSS pada air permukan. Metode penelitian dilakukan dengan menggunakan membran keramik ukuran diameter 10 cm dan tinggi 20 cm yang terbuat dari tanah lempung, pasir kwarsa dan serbuk gergaji dengan komposisi 7,5% (membran 1 dan 10% (membran 2 bertujuan untuk membuat porositas dan pembakaran pada temperatur 900 – 1200 oC. Selanjutnya air permukaan dialirkan pada membran keramik secara kontinyu. Pengujian E.Coli dan TSS dilakukan pada menit ke 30, 60, 90, 120, 150, dan 180 dari waktu pengaliran. Dari hasil pengujian E. Coli dan TSS, diketahui bahwa membran keramik dapat menurunkan parameter E.Coli dan TSS pada air permukaan. E. Coli menurun hingga 98% untuk kedua membran 7,5% dan 10 % serbuk gergaji. Sedangkan TSS menurun hingga 72,55% pada membran keramik 7,5 % dan 65,22% pada membran 10%.

  16. Karakterisasi Enzim Kitosanase dari Bakteri Kitinolitik T5a1 yang Diisolasi dari Terasi

    Directory of Open Access Journals (Sweden)

    Dewi Seswita Zilda

    2006-04-01

    Full Text Available Bakteri kitinolitik yang mendegradasi kitin dan turunannya telah banyak diisolasi dari berbagai sumber seperti tanah, spons dan limbah udang dan rajungan. Sumber lain yang diduga potensial untuk isolasi bakteri kitinolitik adalah terasi yang merupakan produk fermentasi berbahan baku rebon. Kitosanase adalah enzim kitinolitik yang terlibat dalam produksi kitooligosakarida yang lebih larut air dan berguna dalam berbagai bidang seperti nutrasetikal, medik, dan farmasi. Isolat T5a1, salah satu isolat kitinolitik yang diisolasi dari terasi, ditumbuhkan pada medium minimal sintetik (MSM dengan penambahan 0,5% koloidal kitin pada 37o C, 100 rpm, di inkubator goyang selama 24 jam untuk produksi kitosanase. Enzim kasar kemudian dipekatkan menggunakan amonium sulfat dan didialisis. Dari hasil karakterisasi, diketahui pH dan suhu optimum aktivitas enzim adalah 7 dan 50o C. Enzim stabil pada suhu 40o C selama lebih dari 200 menit. Penambahan ion Mg2+ dan Zn2+ menurunkan aktivitas enzim sampai 15% sementara penambahan ion Ca2+ meningkatkan aktivitas enzim sampai 37%.

  17. UJI KETAHANAN LARVA UDANG GALAH DARI BEBERAPA SUMBER POPULASI TERHADAP BAKTERI Vibrio harveyi

    Directory of Open Access Journals (Sweden)

    Ikhsan Khasani

    2016-11-01

    Full Text Available Salah satu penyakit yang sering menyerang udang di pembenihan adalah vibriosis, yang disebabkan oleh bakteri Vibrio harveyi. Penelitian bertujuan untuk mengetahui tingkat ketahanan beberapa strain larva udang galah, yaitu asal Sungai Ogan, Sumatera Selatan; Sungai Asahan, Sumatera Utara; Sungai Barito, Kalimantan Selatan; Sungai Ciasem, Jawa Barat; dan strain GIMacro terhadap infeksi bakteri Vibrio harveyi, sebagai dasar perakitan varietas unggul udang galah. Penelitian dilakukan dengan Rancangan Acak Lengkap (RAL dengan lima perlakuan, yaitu strain larva dan tiga ulangan. Larva udang galah stadia 4 dari 5 populasi berbeda, dengan panjang rata-rata 2,7±0,4 mm ditempatkan di stoples volume 3 L dengan padat penebaran  larva 100 ekor/L. Setiap wadah diisi 1 L air payau 10‰. Selanjutnya diinfeksi bakteri V. harveyi patogen berumur 24 jam dengan kepadatan 105 cfu/mL. Nauplii Artemia diberikan pada pagi dan sore hari. Parameter yang diamati meliputi pengamatan visual abnormalitas larva uji yang dilihat dari tingkah laku larva dan kondisi organ hepatopankreas, tingkat sintasan, kelimpahan total bakteri Vibrio sp. dan V. harveyi, identifikasi bakteri, dan parameter kualitas air. Selama 48 jam perlakuan sintasan larva yang berasal dari strain induk yang berbeda memberikan hasil berbeda nyata dengan tingkat sintasan tertinggi pada larva asal Barito, yaitu 75%; diikuti GIMacro 65%; Asahan 61,33%; Ciasem 53,66%; strain Ogan 20%. Vibriosis caused by Vibrio harveyi is a serious problem in intensive system hatcheries of freshwater prawn. This study was conducted to study the resistance of larvae from different locations i.e. Ogan River, South Sumatra; Asahan River, North Sumatra; Barito River, South Kalimantan; Ciasem River, West Java; and GIMacro, as part of breeding program to create superior prawn strain. Complete randomized design was used in this study, with 5 treatments, i.e. larvae source and 3 replications. 4th stage of freshwater prawn larvae from

  18. PENAPISAN ISOLAT BAKTERI Streptococcus spp. SEBAGAI KANDIDAT ANTIGEN DALAM PEMBUATAN VAKSIN, SERTA EFIKASINYA UNTUK PENCEGAHAN PENYAKIT STREPTOCOCCOSIS PADA IKAN NILA, Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Taukhid Taukhid

    2011-04-01

    Full Text Available Riset dengan tujuan untuk memperoleh isolat kandidat yang imunogenik bagi pembuatan vaksin untuk pengendalian penyakit streptococcosis pada ikan nila telah dilakukan. Karakterisasi dilakukan secara biokimia dan API 20 STREP terhadap 15 isolat bakteri Streptococcus spp. Uji Koch’s Postulate kemudian dilakukan untuk mengetahui peran bakteri pada infeksi streptococcosis pada ikan nila. Konfirmasi taksonomis hingga level spesies isolat bakteri S. agalactiae dilakukan dengan teknik Polymerase Chain Reaction (PCR dengan menggunakan primer spesifik. Uji patogenisitas dilakukan terhadap 6 isolat yang terdiri atas 5 isolat S. agalactiae (N3M, N4M, N14G, N17O, NK1 dan 1 isolat S. iniae (N2O. Hasil penapisan menunjukkan bahwa bakteri S. agalactiae (N4M memiliki nilai LD50 terkecil, dan nilai terbesar dimiliki oleh bakteri S. iniae (N2O. Isolat bakteri N4M digunakan sebagai sumber antigen dalam pembuatan vaksin anti streptococcosis. Vaksin disiapkan dalam bentuk sel utuh dan diinaktivasi dengan formalin, pemanasan, dan sonikasi. Nilai titer antibodi dan sintasan tertinggi diperoleh pada kelompok ikan yang divaksin dengan formalin killed vaccine dibandingkan dengan teknik inaktivasi lainnya (heat killed vaccine dan sonicated vaccine.

  19. Uji Daya Hambat Air Perasan Buah Jeruk Nipis (Citrus aurantifolia s. Terhadap Pertumbuhan Bakteri Staphylococcus Aureus Secara In Vitro

    Directory of Open Access Journals (Sweden)

    Abdul Razak

    2013-01-01

    Full Text Available AbstrakJeruk Nipis (Citrus aurantifolia S. merupakan salah satu tanaman obat keluarga yang banyak terdapat ditengah masyarkat dan banyak digunakan sebagai ramuan tradisional. Bagian yang sering digunakan adalah air perasannya, dengan salah satu manfaat dapat digunakan untuk menghilangkan jerawat serta penyembuhan luka agar tidak terjadi abses. Jerawat dan abses pada luka merupakan salah satu infeksi yang disebabkan oleh bakteri Staphylococcus aureus.Tujuan Penelitian ini adalah untuk mengetahui daya hambat air perasan buah jeruk nipis (Citrus aurantifolia S. terhadap pertumbuhan bakteri Staphylococcus aureus secara invitro. Penelitian dilakukan dengan metoda eksperimental laboratorium dengan desain postest only control group design yang dilakukan di Laboratorium Mikrobiologi Fakultas Kedokteran Universitas Andalas.Hasil penelitian menunjukan bahwa air perasan buah jeruk nipis memiliki daya hambat terhadap pertumbuhan bakteri Staphylococcus aureus dengan berbagai konsentrasi yaitu 25%, 50%, 75%, dan 100% dan terdapat pengaruh lama kontak terhadap pertumbuhan bakteri dimana bakteri tidak tumbuh seteleh kontak 5 menit pertama dan diikuti menit-menit berikutnya dengan air perasan buah jeruk nipis konsentrasi 100%. Jadi, semakin tinggi konsentrasi air perasan buah jeruk nipis dan semakin lama kontak dengan bakteri Staphylococcus aureus maka daya hambatnya semakin baik.Kata kunci: Uji Daya Hambat, Air Perasan Buah Jeruk Nipis, Staphylococcus aureus.Abstract Lime (Citrus aurantifolia S. is kind of family’s herbal medicine, most using in the community is widely used as a traditional herb. The most common used part is the lime fruit squeeze with one of the function is used for removing acne and wound healing to prevent the form of abscess. Pimples and abscesses of the wound is one of the infections caused by the bacterium Staphylococcus aureus.The purpose of this study was to determine the inhibition of lime fruit (Citrus aurantifolia S. squeeze

  20. Identifikasi Bakteri Coliform pada Air Kobokan di Rumah Makan Kelurahan Andalas Kecamatan Padang Timur

    Directory of Open Access Journals (Sweden)

    Ervan Arditya Kusuma

    2015-09-01

    Full Text Available Abstrak Air kobokan merupakan media untuk cuci tangan yang banyak digunakan di rumah makan di  Kota Padang. Diare adalah penyakit yang ditularkan melalui air yang terkontaminasi oleh bakteri. Angka perkiraan kasus diare di Padang Timur merupakan yang tertinggi di Kota Padang. Tujuan penelitian ini adalah untuk mengetahui kualitas mikrobiologi air kobokan di rumah makan di Kelurahan Andalas Kecamatan Padang Timur. Sebanyak 21 sampel yang diambil dan dibagi sesuai dengan sumber airnya yaitu 12 sumber air PDAM dan 9 sumber air sumur bor. Penelitian ini dibagi dalam dua tahap, tahap pertama:  pengambilan sampel dan observasi faktor yang mempengaruhi kontaminasi. Kedua: uji bakteriologi dengan metode Most Propable Number (MPN yang meliputi uji penduga, uji konfirmasi dan uji lengkap.Seluruh sampel air kobokan mengandung bakteri coliform. Sebagian besar sampel tidak memenuhi syaratmikrobiologis sesuai dengan PERMENKES no 46 tahun 1990 dan hanya satu sampel yang berasal dari air PDAM memenuhi syarat mikrobiologis. Sampel yang berasal dari PDAM didapatkan 4 yang mengandung E.coli dan dari sumber sumur bor didapatkan 3 sampel mengandung E.coli dan lainnya mengandung bakteri lain seperti Klebsiella, Enterobacter dan Pseudomonas. Hal ini dipengaruhi oleh banyak faktor seperti kebersihan wadah, lokasi rumah makan dan lokasi sumur bor.Kata kunci: air kobokan, most propable number (MPN. Abstract Water is the common use for hand washing in restaurant in Padang city. The research was conducted at restaurant in Andalas, East Padang. Diarrhea is a disease transmitted through water contaminated by bacteria.Morbidity of diarrhea in East Padang is the highest in Padang. The objective of this study was to identify microbiological quality of water for cleaning hand at Restaurant in Andalas sub-district, East Padang district. Total 21 sampels were taken and divided according to the water source is 12 by PDAM and 9 from dug well. This research implemented in two

  1. PENGARUH PARAQUAT TERHADAP BAKTERI TANAH, Rhizobium sp. (Influence of Paraquat Herbicide on Soil Bacteria Rhizobium Sp.

    Directory of Open Access Journals (Sweden)

    Erni Martani

    2001-08-01

    Full Text Available ABSTRAK Pencemaran pestisida merupakan salah satu masalah lingkungan yang menyebabkan gangguan terhadap organisme tanah. Paraquat adalah bahan aktif beberapa jenis herbisida yang banyak diaplikasikan di lahan gambut dan lahan pertanian tadah hujan. Studi ini dilakukan untuk mengetahui pengaruh herbisida paraquat terhadap bakteri Rhizobium sp. Tiga puluh lima strain Rhizobium sp. telah diuji dengan menggunakan teknik difusi cakram kertas (paper disc. Sebagian strain adalah hasil isolasi dari ranah, bintil akar tanaman Ieguminosa dan inokulum leguminosa (Legin - Iegume Inoculum. Enam strain lain aclalah bakteri Rhizobium japonicum. Hasil penelitian menunjukkan hahwa paraquat memiliki daya hambat terhadap hakteri Rhizohium sp. Sebanyak 17,14% (enam strain dari seluruh strain yang diuji, tidak mengalami penghambatan sampai konsentrasi paraquat 400 ppm. Bakteri ini memiliki prospek bagus untuk digunakan sebagai inokulum rhizobium terutama di lahan pertanian yang telah tercemari herbisida, khususnya yang mempunyai bahan aktif paraquat. Sebagian besar strain yang digunakan (82,86% terhambat oleh 20 ppm parakuat dan daya hambat tersebut makin besar seiring dengan meningkatnya konsentrasi paraquat. Mengingat makin meluasnya pemakaian herbisida berbahan aktif paraquat di Indonesia dan peran Rhizobium dalam fiksasi nitrogen, hasil penelitian ini fiksasi memiliki arti penting, terutama bagi petani agar berhati-hati dalam pemakaian pestisida.   ABSTRACT Pesticedes may cause environmental pollution which lead to disturbance of soil biota. Paraquat is an active agent of herbicides usually used in peat land and rainfed agriculture. This research was conducted to examine the influence of paraquat on symbiotic nitrogen fixing bacteria, Rhizobium sp. Thirty five trains of the genus Rhizobium were examined in this research. Some of them were isolated from soils, legume root nodules, and legume Inoculum. Six stains of Rhizobium japonicum were also used in this

  2. Seleksi dan Karakterisasi Bakteri Penambat Nitrogen Non Simbiotik Pengekskresi Amonium Pada Tanah Pertanaman Jagung (Zea mays L. dan Padi (Oryza sativa L. Asal Kabupaten Barru, Sulawesi Selatan, Indonesia

    Directory of Open Access Journals (Sweden)

    . Hartono

    2015-06-01

    Full Text Available Penelitian ini merupakan penelitian deskriptif yang bertujuan untuk menyeleksi (screening bakteri penambat nitrogen non simbiotik yang diisolasi dari rhizosfer tanaman jagung (Zea mays L. dan padi (Oryza sativa L. yang memiliki kemampuan mengekskresikan amonium. Sampel diambil dari daerah Mangkoso, Kabupaten Barru, Provensi Sulawesi Selatan pada daerah rhizosfer tanaman. Isolasi bakteri penambat nitrogen dilakukan dengan menggunakan medium pertumbuhan bebas nitrogen yaitu medium Burk’s dan Ashby. Koloni bakteri yang tumbuh pada medium pertumbuhan selanjutnya dimurnikan dan diuji kemampuan ekskresi amoniumnya dengan menggunakan metode spectrophotometry. Isolat bakteri yang memiliki kemampuan mengekskresikan amonium dikarakterisasi secara morfologi dan fisiologis. Hasil penelitian menunjukkan terdapat 20 isolat bakteri yang mampu tumbuh pada medium bebas nitrogen, namun setelah dilakukan uji ekskresi amonium hanya diperoleh 9 isolat yang memiliki kemampuan mengekskresikan amonium dari masing-masing medium pertumbuhan. Isolat bakteri dan konsentrasi amonium yang diekskresikan masing-masing adalah ABJ211 (179 µg/L, ABP213 (269 µg/L, ABP211 (162 µg/L, ABP131 (254 µg/L, ABP242 (104 µg/L, BBJ221 (263 µg/L, BBJ222 (272 µg/L, BBP222 (269 µg/L dan BBP214 (257 µg/L. Kesembilan isolat tersebut memiliki karakteristik morfologi dan fisiologis yang bervariasi terutama pada sifat struktur dinding sel (gram, kemampuan hidrolisis pati, gelatin dan kasein, sementara kemampuan dalam mereduksi nitrat dan H2O2 (reaksi katalase positif serta fermentasi glukosa menunjukkan karakter yang seragam.Kata kunci: Bakteri Penambat Nitrogen, Non Simbiotik, Ekskresi Amonium, Karakterisasi Morfologi dan Fisiologis

  3. Studium bioremediace vybraných organických polutantů pomocí bakterie Cupriavidus necator

    OpenAIRE

    Miléřová, Miluše

    2014-01-01

    Cílem práce je studium bioremediace p-nitrofenolu pomocí bakterie Cupriavidus necator. V teoretické části je zpracován přehled organických polutantů a bioremediačních technologií sloužících k jejich odstranění ze životního prostředí. V experimentální části byla pro biodegradaci p-nitrofenolu použita bakterie Cupriavidus necator H16 a její mutantní kmen Cupriavidus necator H16/PHB-4 neschopný akumulace PHB. Biodegradační testy byly provedeny s různými koncentracemi p-nitrofenolu a také za neop...

  4. POTENSI ANTIMIKROBA EKSTRAK SAMBILOTO (ANDROGRAPHIS PANICULATA NESS. DAN KUNYIT (CURCUMA LONGA LINN. SERTA KOMBINASINYA TERHADAP BAKTERI ESCHERICHIA COLI IN VITRO

    Directory of Open Access Journals (Sweden)

    Luh Putu Happy Sandha

    2015-01-01

    Full Text Available Penggunaan tanaman tradisional sebagai obat telah banyak dikembangkan sebagai solusi pada kasus resistensi antibiotik. Penelitian ini bertujuan untuk menentukan aktivitas antimikroba dari ekstrak sambiloto, kunyit serta kombinasinya terhadap pertumbuhan bakteri gram negatif Esherichia coli. Penelitian ini adalah penelitian eksperimental murni yang dilakukan secara in-vitro. Ekstrak sampel kunyit dan sambiloto diperoleh dari proses ekstraksi menggunakan methanol 95%. Aktivitas antimikroba dinilai dari diameter zona hambat yang terbentuk pada bakteri E. coli dengan metode difusi cakram. Hasil penelitian ini ditemukan bahwa kombinasi ekstrak sambiloto dan kunyit memiliki potensi antimikroba yang bermakna terhadap bakteri E. coli dengan zona hambat sebesar 27,33 mm (p=0,002 pada konsentrasi 15 µg/ml. Ekstrak kunyit tunggal memiliki potensi antimikroba terhadap E. coli pada konsentrasi 15 µg/ml dengan zona hambat 28,67 mm (p=0,004. Ekstrak sambiloto tunggal tidak memiliki potensi antimikroba untuk E. coli. Simpulan penelitian ini yaitu penggunaan kunyit sebagai antimikroba tunggal memiliki potensi yang lebih baik dibandingkan kombinasi ekstrak, sehingga tidak perlu dikombinasi dengan sambiloto.    

  5. Uji Efektivitas Jeruk Nipis (Citrus aurantifolia dalam Mempercepat Laju Disinfeksi Bakteri Escheria Coli pada Proses Solar Water Disinfection

    Directory of Open Access Journals (Sweden)

    Saprian Saprian

    2015-08-01

    Full Text Available Solar Water Disinfection (SODIS memerlukan waktu rata-rata berkisar antara 5-6 jam untuk dapat membunuh bakteri 3-4 Log pada air berkapasitas maksimal 2 liter atau 1 jam dengan suhu di atas 50°C. Penelitian terbaru menunjukkan bahwa dengan mengkombinasikan SODIS dengan psoralens, zat aktif seperti yang terdapat pada jeruk Lemon (Citrus Limon dapat menginaktivasi bakteri hingga 5,6 Log reduksi dalam rentang waktu 30 menit pada suhu 29°C. Mengingat faktor ketersediaan dan harga jeruk lemon di Indonesia maka pada penelitian ini dilakukan pengamatan dengan menggunakan jeruk nipis (Citrus aurantifolia. Penelitian ini dilakukan untuk mengetahui seberapa besar potensi jeruk nipis untuk dipergunakan dalam mempercepat laju disinfeksi pada proses SODIS. Adapun faktor-faktor yang akan dipelajari terkait dengan hubungan antara variasi dosis jeruk nipis, perubahan pH dan suhu air terhadap efisiensi inaktivasi bakteri yang mampu dihasilkan. Variasi jeruk nipis yang digunakan adalah 0%, 2%, 4% dan 6% dengan variasi waktu 0 menit, 30 menit, 60 menit dan 120 menit. Hasil penelitian menunjukkan bahwa perlakuan SODIS dengan menggunakan jeruk nipis mampu menginaktivasi E. coli sebesar 5.4 Log dengan waktu 1 jam pada suhu 32°C. Hal ini menunjukkan bahwa Jeruk nipis berpotensi untuk digunakan dalam mempercepat laju disinfeksi E. coli pada air minum. Kata Kunci : SODIS, E.coli, Psoralens, Jeruk Nipis

  6. Uji Daya Hambat Ekstrak Buah Belimbing Manis (Averrhoa carambola terhadap Pertumbuhan Bakteri Streptococcus pneumoniae secara In Vitro

    Directory of Open Access Journals (Sweden)

    Rita Risandi

    2016-09-01

    Full Text Available AbstrakBuah belimbing manis (Averrhoa carambola merupakan salah satu tanaman Indonesia yang diyakini memiliki khasiat obat. Salah satu manfaat yang dapat diambil dari sari buah belimbing manis (Averrhoa carambola adalah dapat mengobati radang tenggorokan. Radang tenggorokan merupakan salah satu infeksi yang disebabkan oleh bakteri Streptococcus pneumoniae. Tujuan penelitian ini adalah menentukan daya hambat ekstrak buah belimbing manis (Averrhoa carambola terhadap pertumbuhan bakteri Streptococcus pneumoniae  secara in vitro. Metode studi ini ialah eksperimental dengan desain postest only control group design yang dilakukan di Laboratorium Biota Sumatera Universitas Andalas dan Laboratorium Mikrobiologi Fakultas Kedokteran Universitas Andalas dari Agustus sampai Oktober 2014. Hasil penelitian menunjukkan bahwa ekstrak buah belimbing manis (Averrhoa carambola dengan konsentrasi yaitu 5%, 10%, 15% dan 20% tidak memiliki daya hambat terhadap pertumbuhan bakteri Streptococcus pneumoniae.  Hal ini terbukti karena tidak terbentuk zona hambat pada agar darah dan tidak terdapat pengaruh lama kontak ekstrak buah belimbing manis (Averrhoa carambola  terhadap pertumbuhan bakteri Streptococcus pneumoniae secara in vitro. Ekstrak buah belimbing manis tidak memiliki efek antibakteri terhadap pertumbuhan bakteri Streptococcus pneumoniae.Kata kunci: ekstrak buah belimbing manis, Streptococcus pneumoniae, daya hambat Abstract             Star fruit (Averrhoa carambola is a Indonesian plant that is believed to have medicinal properties. One of the benefits that can be drawn from the juice of star fruit (Averrhoa carambola is the ability to treat strep throat. Strep throat is a bacterial infection caused by Streptococcus pneumoniae. The objective of this study was to determine the inhibitory extract of star fruit (Averrhoa carambola on the growth of the bacterium Streptococcus pneumoniae in vitro. This was an experimental  research  with design

  7. Identifikasi Carrier Bakteri Streptococcus β hemolyticus Group A pada Murid SD Negeri 13 Padang Berdasarkan Perbedaan Umur dan Jenis Kelamin

    Directory of Open Access Journals (Sweden)

    Fadhila Aini

    2016-01-01

    Full Text Available AbstrakStreptococcus β hemolyticus Grup A atau yang disebut juga Streptococcus pyogenes merupakan salah satu bakteri patogen yang banyak menginfeksi manusia.Bakteri ini dapat ditemukan sebagai carrier di saluran pernafasan terutama pada anak-anak, tidak menimbulkan penyakit tetapi berisiko untuk menyebarkan penyakit. Tujuan penelitian ini adalah menentukan jumlah carrier  bakteri Streptococcus β hemolyticus Grup A pada murid berdasarkan perbedaan umur dan jenis kelamin. Jenis penelitian ini adalah deskriptif cross-sectional dengan menggunakan sampel seluruh murid SD Negeri 13 Padang. Hasil penelitian adalah didapatkan 2 orang murid yang menderita carrier, yaitu pada kelompok usia>8-9 tahun dan >11 tahun. Berdasarkan jenis kelamin yang terdiri dari 54 orang laki-laki dan 50 orang perempuan, didapatkan 2 orang carrier yaitu hanya pada anak laki-laki. Hasil penelitian menunjukkan bahwa carrier bakteri Streptococcus β hemolyticus Group  A terdapat pada anak usia tersebut karena masih kurangnya pengetahuan tentang kebersihan. Carrier yang ditemukan hanya pada anak laki-laki kemungkinan disebabkan mereka lebih sering bermain di luar rumah dan terpapar dengan berbagai bakteri patogen dan kurang memperhatikan kebersihan diri.Kata kunci: carrier, streptococcus β hemolyticus grup A, umur, jenis kelamin AbstractGroup A Streptococcus β hemolyticus or also called Streptococcus pyogenes is one of many pathogenic bacteria that infect humans. These bacteria can be found as a carrier in the respiratory tract especially in children, do not cause disease but can be a risk for spreading the disease. This objective of this study was to determine the amount of the carrier of bacteria group A Streptococcus β hemolyticus based on age and gender differences. This research is a descriptive cross - sectional study using a sample of all students of SD Negeri 13 Padang. Based on the age of 104 students found that students who suffer 2 carrier, which is in the age

  8. Perbedaan Daya Hambat Bakteri dari Propolis Cair yang Ada di Pasaran Terhadap Escherichia Coli dan Staphylococcus Aureus Secara In Vitro

    Directory of Open Access Journals (Sweden)

    Bangun Azhari Yusuf

    2015-09-01

    Full Text Available Abstrak Propolis adalah zat yang digunakan lebah melindungi sarangnya dari berbagai ancaman. Komponen utama propolis adalah resin yang dikumpulkan lebah dan dicampur dengan air liurnya. Manusia juga menggunakan propolis sebagai obat berbagai penyakit, seperti infeksi bakteri. Propolis memiliki kemampuan antibakteri terhadap Escherichiacoli dan Staphylococcus aureus. Kualitas dan jenis propolis sesuai dengan komposisi kimia, iklim dan tempat berkembang biak. Tujuan penelitian ini adalah melihat perbedaan daya hambat bakteri Propolis cair 1 dan Propolis cair 2 yang ada di pasaran terhadap Escherichia coli dan Staphylococcus aureus secara in vitro. Propolis yang akan diuji adalah propolis cair yang ada di pasaran dipilih dua secara acak. Penelitian dilaksanakan pada bulan Januari 2013 di laboratorium Mikrobiologi Fakultas Kedokteran Universitas Andalas. Jenis penelitian eksperimentalmenggunakan metode difusi (metode cakram dan analitik dengan menghubungkan perbedaan kedua propolis sebagai antibakteri. Hasil penelitian ini menunjukkan propolis cair 1 dan propolis cair 2 yang ada di pasaran tidak memiliki efek antibakteri terhadap Escherichia coli dan terdapat perbedaan daya hambat bakteri dari kedua propolisterhadap Staphylococcus aureus. Propolis cair 2 (diklaim berasal dari Selandia baru memiliki daya hambat bakteri yang lebih baik daripada propolis cair 1 (diklaim berasal dari Malaysia.Kata kunci: propolis cair, perbedaan daya hambat bakteri, Escherichia coli, Staphylococcus aureusAbstract Propolis is substance which use to protect bee hive from various threat. The main component of propolis is resin which is collected and mixed with saliva. The human also use propolis as a treatment against various illness such as bacterial infection. Propolis has an antibacterial effect to Escherichia coli and Stahpylococcus aureus. The quality and type of propolis is also in accordance with chemical composition, climate and their breeding location. The

  9. POTENSI TUMBUHAN BANGKAL (Nauclea Orientalis UNTUK PENGENDALIAN BAKTERI Aeromonas Hydrophila (POTENTIAL PLANT BANGKAL (Nauclea orientalis FOR CONTROL Aeromonas Hydrophila

    Directory of Open Access Journals (Sweden)

    Siti Aisiah

    2017-02-01

    Full Text Available Tujuan penelitian ini adalah didapatkan metode pengendalian penyakit yang disebabkan oleh bakteri Aeromonas hydrophila pada budi daya ikan yang ramah lingkungan. Dalam penelitian ini dilakukan uji sensitivitas terhadap bakteri A. hydrophila, uji minimal konsentrasi menghambat  bakteri A. hydrophila (uji MIC dan uji toksisitas terhadap ikan nila. Rancangan  yang digunakan untuk  uji toksisitas  adalah rancangan acak lengkap (RAL, dengan 4 perlakuan yaitu A  = Ikan disuntik dengan ekstrak bangkal konsentrasi 20%, B  = Ikan disuntik dengan ekstrak bangkal konsentrasi 40%,  C  = Ikan disuntik dengan ekstrak bangkal konsentrasi 80%, dan D  = Kontrol (ikan tidak disuntik, diulang sebanyak 3 kali. Perlakuan ini didapat dari hasil uji sensitivitas antibakteri bangkal yang mempunyai daya hambat dan daya bunuh paling besar terhadap bakteri A. hydrophila yaitu ekstrak daun bangkal dengan pelarut akuades. Pengujian MIC menunjukkan bahwa ekstrak bangkal-akuades memiliki daya hambat minimal  20 % terhadap aktivitas bakteri A. hydrophila. Hasil uji toksisitas yang dilakukan terhadap ikan nila dengan konsentrasi 20%, 40% dan 80%  mortalitas ikan nila dibawah 50 %. Pengamatan hematologis yaitu eretrosit, leokosit, plasma darah, hematokrit dan leokokrit pada masing-masing perlakuan sebagian besar masih berada dalam kisaran yang normal. Parameter kualitas air yaitu, kadar oksigen terlarut,  pH, amoniak, CO2 dan suhu masih dapat mendukung kehidupan normal ikan nila. The purpose of this study was obtained method of controlling diseases caused by Aeromonas hydrophila in fish farming is environmentally friendly. In this study the sensitivity of the test  A. hydrophila, a minimum test konsentari inhibiting A. hydrophila (MIC test and toxicity test on  tilapia. The design used for toxicity tests is completely randomized design with 4 treatments it A = Fish injected with extracts bangkal concentration of 20 %,  B = Fish injected with extracts bangkal

  10. EFEKTIVITAS KRIM EKSTRAK METANOL BATANG DAN DAUN PACAR AIR (Impatiens balsamina L. TERHADAP BAKTERI Propionibacterium acnes

    Directory of Open Access Journals (Sweden)

    Wendy Wendy

    2017-03-01

    Full Text Available Colonization of Propionibacterium acnes is one of factors that causes acne vulgaris. The present study was conducted to evaluate antiacne effect from cream of methanolic extract from stems and leaves of Impatiens balsamina L. towards Propionibacterium acnes, concentration that gives greatest antiacne effect and to evaluate physical and chemical properties of creams. Simplicia were extracted using soxhlet technique and methanol as solvent. Extract then formulated in cream in three variations of concentration as following 10%(F1, 15%(F2 and 20%(F3. The determination of antiacne effect was done using disc diffusion method. Evaluation of physical and chemical properties of those creams includes organoleptic examination, spreadability, adhesion and pH testing. Determination results showed the diameter of inhibition zone from F1, F2 and F3 were 8,37±2,205; 10,78±2,551; and 17,42±3,029 mm respectively. Analysis results showed that cream of F3 gave significantly greatest antiacne effect compared to F1 and F2 (p0,05. The evaluation of creams showed that they had homogenous texture, nongreasy, easily washed, spreadability of 10,18±0,285 to 11,55±0,687 cm2, adhesion force of 33,299±2,821 to 60±0 minutes, and pH of 6,07±0,058 to 6,37±0,115, this showed that creams have good physical and chemical properties. Keywords: Antiacne, Impatiens balsamina L. stems and leaves extract, Propionibacterium acnes   ABSTRAK Kolonisasi bakteri Propionibacterium acnes merupakan salah satu penyebab terjadinya jerawat. Penelitian ini dilakukan untuk mengetahui efek antijerawat krim ekstrak metanol batang dan daun pacar air (Impatiens balsamina L. terhadap bakteri Propionibacterium acnes, mengetahui konsentrasi krim yang memberikan efek antijerawat yang paling besar serta mengevaluasi sifat fisik dan kimia krim. Simplisia disokletasi menggunakan pelarut metanol. Ekstrak diformulasikan ke dalam sediaan krim dengan variasi konsentrasi ekstrak yaitu 10%(F1, 15%(F2 dan 20

  11. AKTIVITAS ANTIBAKTERI EKSTRAK DAUN BAKAU HITAM (Rhizophora mucronata TERHADAP BAKTERI PENYEBAB DIARE

    Directory of Open Access Journals (Sweden)

    Kustiariyah - tarman

    2014-06-01

    Full Text Available Daun Rhizophora mucronata dimanfaatkan masyarakat pesisir sebagai obat tradisional untuk mengobatidiare. Tujuan penelitian ini adalah mendapatkan ekstrak daun R. mucronata dan potensinya untuk dijadikansediaan obat baru yang alami, khususnya untuk mengobati diare. Metode penelitian yang dilakukanmenggunakan uji sensitivitas antibakteri dengan metode sumur agar. Ekstrak metanol daun bakau hitammemiliki rendemen tertinggi sebesar 21,47%. Komponen aktif yang terkandung dalam ekstrak metanol danair daun R. mucronata meliputi tanin, saponin, fl avonoid, fenol hidrokuinon, dan triterpenoid, sementaraalkaloid hanya terdapat pada ekstrak metanol. Ekstrak metanol memiliki aktivitas antibakteri terbesardengan zona hambat berkisar 3-12 mm. Konsentrasi hambat minimum (KHM ekstrak metanol daun R.mucronata sebesar 0,4 mg/mL (terhadap Escherichia coli dan Pseudomonas aeruginosa, 0,2 mg/mL (terhadapStaphylococcus aureus. Bioautografi aktivitas antibakteri terhadap bakteri uji E. coli menghasilkan fraksiaktif pada nilai Rf 0,11 dan 0,72. Hasil identifi kasi dengan pereaksi Dragendorff menunjukkan senyawatersebut termasuk senyawa alkaloid.Kata kunci: antibakteri, diare, ekstrak daun R. mucronata, KHM, komponen aktif

  12. Peran Kalsium Intraseluler pada Respon Seluler terhadap Intermedilysin Bakteri Komensal Oral Streptococcus Intermedius

    Directory of Open Access Journals (Sweden)

    Heni Susilowati

    2011-06-01

    Full Text Available Latar Belakang. Bakteri komensal oral Streptococcus intermedius mampu memproduksi intermedilysin (ILY, toksin yang berpotensi menyebabkan terbentuknya pori pada membran, yang termasuk dalam golongan cholesterol-dependent cytolysin. Toksin ini dikenal sebagai sitolisin yang unik karena sifatnya yang spesifik hanya menimbulkan respon pad a sel-sel manusia. Tujuan dari studi literatur ini adalah untuk memahami mekanisme sel-sel tubuh manusia dalam merespon paparan ILY. Ringkasan Pembahasan. Penelitian-penelitian terdahulu menunjukkan keterlibatan S. intermedius dalam infeksi purulen oral maupun nonoral karena kemampuannya memproduksi ILY. Intermedilysin diketahui meny.ebabkan ketidakseimbangan metabolisme sel dan kematian sel pada beberapa sel tubuh manusia seperti hepatosit, sel polimorfonuklear, bile duct cell, dan eritrosit. Spesifisitas ILY pada sel-sel tubuh manusia ditentukan oleh ikatan yang eksklusif hanya dengan reseptor membran human CD59. Pada beberapa kasus, ILY menimbulkan respon seluler melalui perubahan konsentrasi kalsium intraseluler ([Ca2+] i. Peningkatan konsentrasi [Ca2+]i mengakibatkan degranulasi sitoplasma pada sel PMN serta aktivasi kalsineurin yang diikuti dengan aktivasi faktor transkripsi NFAT1 pada sel HuCCT1 dan NF-KB pada sel HepG2. Kesimpulan. Studi literatur ini dapat disimpulkan bahwa peningkatan konsentrasi [Ca2+]i berperan penting dalam mekanisme respon seluler sel-sel tubuh manusia terhadap ILY yang diproduksi oleh S. intermedius.

  13. Uji Resistensi Bakteri Escherichia Coli dari Sungai Boyong Kabupaten Sleman terhadap Antibiotik Amoksisilin, Kloramfenikol, Sulfametoxasol, dan Streptomisin

    Directory of Open Access Journals (Sweden)

    Hadi Sasongko

    2014-05-01

    Full Text Available Resistensi mikrobia merupakan masalah yang serius dihadapi oleh ahli-ahli mikrobiologi kesehatan. Hal ini menimbulkan masalah yang menyebabkan antibiotika menjadi tidak berkhasiat bagi penyembuhan penyakit infeksi, perawatan menjadi lebih lama, dan biaya perawatan menjadi lebih tinggi. Penelitian ini dilakukan bertujuan untuk mengetahui resistensi bakteri SE. Coli yang diisolasi dari air sungai dan air rumah tangga sepanjang Sungai Code wilayah Kabupaten Sleman terhadap antibiotika amoksisilin, kloramfenikol, sulfametoxasol, dan streptomisin.Isolasi E. coli dari sumber air sungai dan air rumah tangga dilakukan dengan cara taburan menggunakan medium kromogenik TBX, sedangkan uji resistensi menggunakan metode difusi padat cara Kirby Bauer yang dimodifikasi menngunakan medium Mueller Hinton Agar (MHA. Inokulasi isolat E.coli pada medium MHA dilakukan secara apus menggunakan kapas kidi streril, selanjutnya diletakkan disk antibiotika amoksisilin, kloramfenikol, sulfametoxasol, dan eritromisin di atasnya. Inkubasi dilakukan pada 37 derajat celcius selama 24 jam. Bakteri dapat dikatakan resisten, intermediet ataupun sensitif dengan mengukur zona hambat pada media uji, kemudian membandingkannya dengan Tabel Interpretasi Zona Hambat Standar dari BSAC version 8, January 2009.Dari hasil penelitian menunjukkan bahwa : Isolat bakteri E.coli dari air sungai dan air rumah tangga sepanjang Sungai Code wilayah Sleman telah resisten terhadap antibiotik, khususnya amoksisilin dan streptomisin. Hasil uji resistensi memperlihatkan untuk amoksisilin 80% dan 66.7%, Kloramfenikol : 20% dan 6.7% ; Sulfametoxasol : 33.3% dan 46.7%, serta streptomisin 73.3% dan 86.7%.

  14. ANALISIS AKTIVITAS NITROGENASE DAN GEN NIFH ISOLAT BAKTERI RHIZOSFER TANAMAN PADI DARI LAHAN SAWAH PESISIR JAWA BARAT

    Directory of Open Access Journals (Sweden)

    Dwi Ningsih Susilowati

    2016-12-01

    Full Text Available AbstrakPenambatan nitrogen oleh bakteri rhizosfer dapat dimanfaatkan untuk menyiasati dampak salinitas pada tanah sawah pesisir. Kemampuan tersebut disebabkan oleh aktivitas nitrogenase yang disandikan gen nifH pada komponen II. Penelitian  ini bertujuan  menganalisis aktivitas nitrogenase pada kondisi salin dan mengidentifikasi gen nifH. Sebanyak 50 isolat bakteri rhizosfer asal tanah sawah pesisir daerah Eretan dan Patimban, Jawa Barat telah dianalisis. Lima isolat yang menunjukkan aktivitas nitrogenase pada kondisi salin adalah Er B1 3, Er B1 4, Er B1 9, Er B2 10, dan Ptb B1 4. Gen nifH kelima sampel diidentifikasi menggunakan PCR menghasilkan amplikon berukuran ~360 bp. Aktivitas nitrogenase tertinggi berdasarkan Analisis Reduksi Asetilen (ARA diperoleh pada isolat Er B2 10 yang memiliki kekerabatan terdekat dengan bakteri Providencia sp. Hasil yang diperoleh membuktikan bahwa beberapa bakteri asal sawah pesisir dapat menambat nitrogen pada kondisi salin.AbstractThe ability of nitrogen fixation by rhizosphere bacteria could be used to decrease salinity impact in coastal paddy field, due to nitrogenase capability, encoded by a nifH gene in component II. The objectives of this research are to analyze nitrogenase activity in saline condition and identify the presense of the nifH gene. A total of 50 isolates of the rhizosphere bacteria coastal from wetland areas of Eretan and Patimban, West Java, has been isolated and being analyzed. Among them, five isolates i.e. Er B1 3, ER B1 4, Er B1 9, Er B2 10 and Ptb B1 4, showed the nitrogenase activity under saline condition. The polymerase chain reaction (PCR of the nifH gene from those five samples resulted in the amplicon size of  ~360 bp. The highest activity of nitrogenase assessed by acetylene reduction assay (ARA was shown by Er B2 10 which closely related to bacteria of Providencia sp. The obtained result showed that several bacteria from coastal paddy field were able to conduct nitrogen

  15. Seleksi Bakteri Antagonis Asal Rizosfer Tanaman Cabai (Capsicum sp untuk Menekan Penyakit Layu Fusarium secara in vitro

    Directory of Open Access Journals (Sweden)

    Hilda Karim

    2016-08-01

    Full Text Available Tanaman cabai (Capsicum sp merupakan salah satu komiditi yang memiliki nilai ekonomi tinggi yang rentan terserang penyakit layu yang disebabkan oleh cendawan F.o f.sp capsici . Penelitian ini bertujuan untuk memperoleh cendawan F.o f.sp capsici penyebab penyakit layu pada tanaman cabai yang sakit, untuk memperoleh isolat bakteri antagonis yang mampu menghambat perkembangan cendawan F.o f.sp capsici dan untuk mengetahui keefektifan bakteri antagonis dalam menghambat perkembangan cendawan F.o f.sp capsici penyebab layu pada tanaman cabai. Penelitian ini dilakukan di Laboratorium Biologi FMIPA UNM. Penelitian ini menggunnakan Rancangan Acak Lengkap (RAL dengan 9 perlakuan dan 3 kali ulangan. Analisis data menggunnakan ANOVA dan uji Duncan. Berdasarkan karakter morfologi secara makroskopis dan mikroskopis cendawan yang diisolasi dari tanaman Lombok yang sakit adalah Fusarium oxysporum f.sp capsici . Isolat bakteri antagonis terbaik menghambat pertumbuhan F.o f.sp capsici secara in vitro yaitu  Bacillus sp  81,0% .Kata kunci: Bakteri antagonis,  F.o  f.sp capsici, Tanaman Cabai.ABSTRACTChili Plants (Capsicum sp is one commodity that has high economic value susceptible to wilt disease caused by fungus F.o f.sp capsici. The aim of this research is to obtain fungus Fo f cap capsici cause wilt disease in chilli plant that is sick, to obtain isolate of antagonistic bacteria that able to inhibit fungus development fosp capsici and to know effectiveness of antagonistic bacteria in inhibiting fungus development fosp capsici cause of wilting on pepper plant. This research was conducted in Biology Laboratory of FMIPA UNM. This research used Completely Randomized Design (RAL with 9 treatments and 3 replications. Analyze data using ANOVA and Duncan test. Based on the morphological character of macroscopic and microscopic fungi isolated from the sick Lombok plant is Fusarium oxysporum f.sp capsici. The best antagonistic bacterial isolates inhibited the growth

  16. Perbandingan Oral Care Menggunakan Povidone Iodine 1% dengan Chlorhexidine 0.2% terhadap Jumlah Bakteri di Mulut pada Pasien Penurunan Kesadaran

    Directory of Open Access Journals (Sweden)

    Ni Luh Widani

    2017-09-01

    Full Text Available Oral care klien penurunan tingkat kesadaran tidak boleh diabaikan dan membutuhkan antiseptik oral yang mempunyai sifat antibakteri. Penelitian ini adalah penelitian kuantitatif dengan desain quasi eksperimen dengan kelompok kontrol, pre dan post test untuk mengidentifikasi perbandingkan povidone iodine 1% dengan chlorhexidine 0.2% terhadap jumlah koloni bakteri di mulut klien penurunan kesadaran. Hasil penelitian pada 30 responden yang diambil secara consecutive sampling dibagi tiga kelompok. Ada perbedaan yang signifikan penurunan jumlah koloni bakteri sebelum dan setelah oral care pada povidone iodine (p=0.007, chlorhexidine (p=0.001 dan air (p=0.001. Perbandingan selisih jumlah bakteri antara povidone iodine 1%, chlorhexidine 0.2% dan kontrol tidak signifikan (p=0,343. Disimpulkan chlorhexidine 0.2% , povidone iodine 1% dan air minum masing-masing mempunyai kemampuan yang signifikan menurunkan koloni bakteri dan dapat digunakan sebagai pembilas oral care. Disarankan secara ekonomis air minum digunakan dalam oral care apabila klien penurunan kesadaran tidak mengalami infeksi mulut, dan chlorhexidine 0.2% atau povidone iodine 1% digunakan bila ada infeksi mulut.

  17. Bioaktivitas Senyawa Asam Heksadekanoat dan ??-sitosterol Isolat dariHydroid Aglaophenia cupressina Lamoureoux sebagai BahanAntimikroba pada bakteri Staphilococcus aureus dan jamur Aspergillus flavus

    OpenAIRE

    Yohannes, Eva

    2014-01-01

    Saat ini sangat diperlukan sumber antibiotik baru yang lebih efektif untuk mengatasi Multi Drug Resistant (MDR), pada pengobatan penyakit infeksi yang disebabkan oleh mikroorganisme patogen. Penelitian ini bertujuan untuk mengetahui bioaktivitas senyawa asam heksadekanoat dan ??-sitosterol hasil isolat dari hydroid Aglaophenia cupressina Lamoureoux dalam menghambat atau mematikan bakteri Staphyloccocus aureus dan jamur Aspergillus flavus yang sering mencemari bahan pangan. Metode yang digunak...

  18. Pola Resistensi Bakteri pada Sputum Pasien PPOK Terhadap Beberapa Antibiotika di Laboratorium Mikrobiologi RSUP Dr.M.Djamil Periode 2010 − 2012

    Directory of Open Access Journals (Sweden)

    Ashima Sonita

    2014-09-01

    Full Text Available AbstrakPeningkatan resistensi bakteri penyebab PPOK terhadap beberapa antibiotika yang lazim digunakan oleh klinisi dalam pemberian terapi empirik akan menyebabkan berkurangnya keefektifan terhadap terapi PPOK. Hal ini akan berdampak semakin tingginya morbiditas dan mortalitas yang disebabkan oleh PPOK. Penelitian ini bertujuan untuk mengetahui pola resistensi bakteri penyebab PPOK terhadap beberapa antibiotika di Laboratorium Mikrobiologi RSUP.Dr.M.Djamil periode 2010 – 2012. Penelitian ini telah dilaksanakan pada bulan November 2013 sampai dengan Desember 2013 di Laboratotium Mikrobiologi RSUP Dr.M.Djamil Padang. Metode penelitian yang digunakan adalah deskriptif retrospektif. Hasil penelitian mendapatkan bakteri penyebab PPOK adalah Klebsiella spp (42,44%, Streptococcus α hemolyticus (38,37%, Pseudomonas aeruginosa (12,21%, Staphylococcus aureus (4,65%, Proteus mirabilis (1,16%, Staphylococcus epidermidis (0,58% dan Streptococcus pneumoniae (0,58%. Disimpulkan bahwa bakteri tersering pada sputum pasien PPOK adalah Klebsiella spp. Tingkat resistensi tertinggi adalah Ampicillin, sedangkan tingkat kepekaan tertinggi adalah terhadap Netilmycin.Kata kunci: antibiotika, bakteri, resistensiAbstractIncreased resistance of bacteria that cause COPD to some antibiotics that are commonly used by clicicians in the provision of empiric therapy, it will cause a reduction in the effectiveness of the tratment of COPD. This study aimed to determine the resistance pattern of Bacteria in sputum of patients COPD to some antibiotics in Microbiology Laboratory Dr.M.Djamil Hospital Peroid 2010 – 2012. The research method was a descriptive and retrospective. According to the result, the bacteria that causes COPD is Klebsiella spp (42.44%, Streptococcus α hemolyticus (38.37%, Pseudomonas aeruginosa (12.21%, Staphylococcus aureus (4.65%, Proteus mirabilis (1.16%, Staphylococcus epidermidis (0.58%, and Streptococcus pneumoniae (0.58%. It can be concluded that the

  19. Pengaruh Minyak Atsiri Kapulaga (Amomum cardamomum terhadap Kadar Metil Merkaptan yang Dihasilkan Bakteri Porphyromonas gingivalis (Kajian In Vitro

    Directory of Open Access Journals (Sweden)

    Nuning Wahyu Utami

    2012-07-01

    Full Text Available Latar Belakang: Helitosis disebabkan pembentukan senyawa-senyawa sulfur atau Volatile Sulfur Compound (VSC oleh bakteri. Metil merkaptan merupakan komponen VSC yang paling dominan menyebabkan bau pada halitosis. Agen antibakteri digunakan untuk mengatasi halitosis dengan cara menurunkan kadar metil merkaptan yang dihasilkan bakteri. Minyak atsiri kapulaga (Amomum cardamomum diduga memiliki khasiat anti bakteri. Tujuan penelitian ini adalah untuk mengetahui pengaruh minyak atsiri kapulaga (Amomum cardamomum terdapat kadar metil merkaptan yang dihasilkan porphyromonas gingivalis. Metode Penelitian: Setiap sumuran pada microplate ditetesi minyak atsiri kapulaga  (Amomum cardamomum konsentrasi minyak atsiri kapulaga 0% (control negatif, 6,25%, 12,5%, 25%, 50%. Selanjutnya setiap sumuran yang telah ditetesi minyak atsiri kapulaga berfbagai konsentrasi, kemudian ditetesi suspensi bakteri porphyromonas gingivalis pada media TSB dan diinkubasi anaerob selama 48 jam. Tiap perlakuan menggunakan sampel sebanyak 5 sehingga sumuran yang dibutuhkan sebanyak 25. Setelah itu, semua sumuran ditetesi metionin dan DTNB kemudian diinkubasi anaerob selama 12 jam. Hasil inkubasi tersebut kemudian dilihat absorbansi metil merkaptan dengan microplate reader. Hasil Penelitian: Absorbansi kadar metil merkaptan yang dihasilkan pada minyak atsiri kapulaga 0%, 6,25%, 12,5%, 25%, 50% secara berurutan adalah 1,38, 0,217, 0,215, 0,204, 0,196. Minyak atsiri kapulaga (Amomum cardamomum berpengaruh terhadap kadar metil merkaptan yang dihasilkan porphyromonas gingivalis. Terdapat perbedaan yang bermakna antara kelompok minyak atsiri kapilaga konsentrasi 0% sebagai kontrol negatif dengan minyak atsiri kapulaga 6,25%, 12,5%, 25%, 50% dan tidak ada perbedaan bermakna antara minyak atsiri kapulaga konsentrasi 6,25%, 12,5%, 25%, 50%. Kesimpulan: minyak atsiri kapulaga (Amomum cardamomum dapat menurunkan kadar metil merkaptan yang dihasilkan bakteri porphyromonas gingivalis. Background

  20. Pembuatan Pasta Gigi Katekin Teh Hijau dan Uji Daya Hambat terhadap Bakteri Streptococcus Mutans dan Lactobascillus Ascidopillus

    Directory of Open Access Journals (Sweden)

    Fajriani Fajriani

    2015-06-01

    Peracikan formula dan pembuatan pasta gigi katekin teh hijau dilakukan sesuai hasil uji KHM (MIC. Pasta gigi katekin teh hijau ini dilakukan pengukuran kadar total flavonoid dan total polifenol, selanjutnya pengukuran uji daya hambat pasta gigi katekin teh hijau dilakukan dengan metode difusi menggunakan well (sumuran sebagai reservoar sampel uji terhadap bakteri streptococus mutans dan lactobacilus acidophilus. Hasil diperoleh prodak pasta gigi katekin teh hijau dengan kandungan kadar flavonoid 77% dan kadar polifenol 41%, sedangkan hasil uji diameter hambatan pasta gigi katekin teh hijau terhadap bakteri streptococcus mutans 17,2 mm dan bakteri lactobacillus acidophilus 19,6 mm. Hasil ini menunjukkan bahwa prodak katekin teh hijau ini sangat efektif digunakan sehari-hari sebagai perawatan gigi dan juga sebagai antibakteri kariogenik.   Making Green Tea Catechin Toothpaste and Inhibition Test Against Streptococcus Mutans and Acidophilus Lactobaccilus. The manufacture of this toothpaste is motivated by the desire of researchers to facilitate the public to use natural ingredients of green tea catechins whose result effectiveness against cariogenic bacteria was directly tested inhibition. This study is to find the right formula composition for greentea catechins toothpaste based on the result of the inhibition properties of greentea cathecins against tostreptococcus mutans dan lactobacillus acidophilus. The manufacture of greentea catechins toothpaste was after making catechins extracts and testing minimal inhibition concentration (MIC and minimal bactericidal concentration (MBC using liquid dilution method. The toothpaste was then made according to the result of MIC. The toothpaste’s flavonoid and polyphenol total contain was measured; then the inhibition property of the toothpaste to was measured using diffusion method with wells as the sample reservoar for streptococus mutans dan lactobacilus acidophilus. It is found that the toothpaste contains

  1. Identifikasi Bakteri dan Uji Kepekaan terhadap Antibiotik pada Penderita Tonsilitis di Poliklinik Tht-kl Blu RSU. Prof. Dr. R. D. Kandou Manado Periode November 2012-januari 2013

    OpenAIRE

    Sembiring, Rinny Olivia

    2013-01-01

    :Tonsilitis merupakan peradangan tonsil palatina yang merupakan bagian dari cincin waldeyer.Tonsilitis adalah infeksi (virus atau bakteri) dan inflamasi pada tonsil.Tujuan penelitian ini mendapatkan gambaran jenis kuman pada pemeriksaan hapusan tenggorokan penderita tonsilitis di Poliklinik THT-KL BLU RSUP Prof. Dr. R. D. Kandou Manado dan juga gambaran tentang kepekaan kuman terhadap beberapa antibiotika yang biasa digunakan pada tonsilitis. Penelitian ini bersifat prospektif deskriptif lewa...

  2. Alleen BA vaak niet voldoende

    NARCIS (Netherlands)

    Maas, F.M.; Poldervaart, G.

    2007-01-01

    Voor de vruchtdunning bij appel is in 2007 MaxCel toegelaten. Dit middel, met de werkzame stof benzyladenine (BA), is in de plaats van carbaryl gekomen. Proeven met BA op Elstar, in 2001 en 2003 uitgevoerd door PPO-fruit, bieden nu waardevolle informatie over de (on)mogelijkheden van benzyladenine

  3. Penurunan Kadar IL-1β Makrofag Terpapar Agregat Bakteri Actinomycetemcomitans setelah Pemberian Minyak Atsiri Temu Putih

    Directory of Open Access Journals (Sweden)

    Juni Handajani

    2015-12-01

    Full Text Available Kunci regulator terhadap respons inflamasi diketahui melalui aktivasi interleukin-1β (IL-1β. Makrofag merupakan sel fagosit mononuklear berperan dalam sistem imun innate dan adaptif. Sitokin yang disekresikan makrofag sebagai respons terhadap patogen antara lain IL-1, IL-6, IL-12, TNF-α, dan chemokine. Minyak atsiri temu putih (Curcuma zedoaria Rosc. diduga memiliki efek anti inflamasi. Tujuan penelitian ini adalah untuk mengetahui kadar IL-1β pada makrofag terekspose aggregat bakteri actinomycetemcomitans setelah pemberian minyak atsiri temu putih. Subjek penelitian adalah 10 ekor tikus Wistar jantan yang dibagi menjadi 2 kelompok (perlakuan dan kontrol, masing-masing kelompok terdiri atas 5 ekor. Kelompok perlakuan diberi minum minyak atsiri temu putih dosis 30,6 μl/ml dan kelompok kontrol diberi aquabides selama 14 hari. Gingiva anterior rahang bawah tikus diolesi A.actinomycetemcomitans sebanyak 100 μl dalam CMC 2% pada hari ke-7 setelah pemberian minum bahan uji dan kontrol selama 7 hari. Pada hari ke-15, tikus pada masing-masing kelompok dianestesi lalu makrofag dikoleksi dari cairan peritoneal. Kadar IL-1β makrofag diukur menggunakan ELISA kit (R&D Systems, USA, selanjutnya data dianalisis menggunakan uji-t. Hasil penelitian menunjukkan terdapat penurunan kadar IL-1β setelah perlakuan. Perbandingan kelompok perlakuan dan kontrol menunjukkan perbedaan bermakna (p < 0,05. Disimpulkan bahwa minyak atsiri temu putih kemungkinan memiliki efek anti inflamasi melalui penurunan kadar IL-1β makrofag. IL-1β level of macrophage exposed to A. actinomycetemomitans decreases after administration Curcuma Zedoaria volatile oil. Activation of interleukin-1β (IL-1β is a key regulator of the inflammatory response. Macrophage is a phagocytic mononuclear cell that plays an important role in innate and adaptive immune response. The cytokine secreted by macrophages in response to pathogen are IL-1, IL-6, IL-12, TNF-α and chemokine

  4. KEMAMPUAN FERMENTASI BAKTERI Lactobacillus bulgaricus UNTUK MENGHASILKAN SUSU RENDAH LAKTOSA DARI SUSU YANG RUSAK

    Directory of Open Access Journals (Sweden)

    Heru Yuniati

    2012-11-01

    (IPS tidak semua susu dari peternak dapat diterima oleh Koperasi Pengumpul Susu (KPS, susu segar harus memenuhi beberapa persyratan baik kimia maupun fisik. Penolakan susu oleh Industri Pengelola Susu disebabkan oleh kualitas susu yang tidak memenuhi syarat, antara lain lemak dan laktosa yang sudah terfermentasi mikroorganisme pencemar. Walaupun demikian susu yang ditolak ini bernilai gizi tinggi dengan kadar protein 3,4 g%, yang masih bisa dimanfaatkan untuk pertumbuhan anak. Penelitian ini bertujuan untuk memanfaatkan susu segar yang ditolak KPS menjadi susu rendah laktosa yang dapat digunakan  untuk diet khusus pada  anak/bayi dengan status gizi buruk atau intoleran terhadap laktosa. Bahan (sampel yang digunakan adalah susu segar yang ditolak IPS dan diambil dari Koperasi Pengumpul Susu (KPS Cipanas dan Pengalengan. Analisis komposisi sampel meliputi penentuan kadar protein, kadar lemak, kadar abu, kadar air, kadar laktosa, glukosa, uji mikrobiologis. Analisis dilakukan di Laboratorium Pusat Teknologi Terapan Kesehatan dan Epidemiologi Klinik (Puslitbang Gizi Bogor, Badan Litbang Kementerian Kesehatan RI. Dari hasil analisis, susu yang difermentasi menggunakan bakteri Lactobacillus bulgaricus  dapat menurunkan kadar laktosa  yaitu dari 1,48% menjadi 1,06%. Hasil uji mikrobiologis susu rendah laktosa yaitu 1,55 x104 koloni/g, sedangkan menurut Standar Nasional no 01-6366- 2000 total count susu bubuk 5x104 koloni/g. Kesimpulan penelitian bahwa susu segar yang ditolak oleh Industri Pengolah Susu masih dapat dimanfaatkan menjadi susu yang kadar laktosanya rendah, karena sumber protein dan lemaknya masih tinggi. Hasil penelitian ini memenuhi Standar Nasional Indonesia dan aman untuk dikonsumsi. Kata kunci : susu ditolak, proses fermentasi, laktobacillus bulgaricus, susu tinggi protein dan rendah laktosa.

  5. Perbedaan Efek Antibakteri Kapsul Minyak Bawang Putih (Garlic Oil dan Kapsul Bubuk Bawang Putih (Garlic Powder Terhadap Pertumbuhan Bakteri Staphylococcus aureus dan Escherichia coli Secara In Vitro

    Directory of Open Access Journals (Sweden)

    Ismail Fajri

    2016-08-01

    Full Text Available Abstrak   Bawang putih  telah diekstrak berupa kapsul garlic oil dan kapsul garlic powder sehingga dapat digunakan sebagai alternatif terapi dalam pengobatan penyakit akibat infeksi bakteri. Kandungan kapsul bawang putih yang memiliki efek anti bakteri adalah allicin. Bawang putih mempunyai efek anti mikroba dalam melawan bakteri Gram positif dan Gram negatif, diantaranya Staphylococcus aureus dan Escherichia coli. Di pasaran terdapat dua jenis kapsul bawang putih, yaitu kapsul bubuk bawang putih dan kapsul minyak bawang putih.  Tujuan penelitian ini adalah menentukan perbedaan efek antara antibakteri kapsul minyak bawang putih dan kapsul bubuk bawang putih terhadap pertumbuhan bakteri Staphylococcus aureus dan Escherichia coli.  Penelitian ini dilakukan di laboratorium Mikrobiologi Fakultas Kedokteran Universitas Andalas Padang dari Mei sampai Juni 2014. Jenis penelitian adalah eksperimental dengan menggunakan metode difusi cakram. Hasil penelitian didapatkan kapsul minyak bawang putih dan kapsul bubuk bawang putih tidak memiliki kemampuan untuk menghasilkan zona hambat terhadap bakteri Staphylococcus aureus dan Escherichia coli. Walaupun tiga kali pengulangan,  tidak terdapat efek antibakteri pada kapsul minyak bawang putih dan kapsul bubuk bawang putih.Kesimpulan penelitian ini adalah kapsul minyak bawang putih dan kapsul bubuk bawang putih tidak memiliki efek antibakteri terhadap Staphylococcus aureus dan Escherichia coli.Kata kunci: minyak bawang putih, kapsul bubuk bawang putih, Staphylococcus aureus, Escherichia coli AbstractGarlic extract in garlic oil capsules and garlic powder capsules can be used as alternative therapy in the treatment of diseases caused by bacterial infection. The content of garlic capsules which have anti-bacterial effect is allicin. Garlic has anti-microbial effect against Gram positive and Gram negative, including Staphylococcus aureus and Escherichia coli. In the market there are two types of garlic

  6. Uji Daya Hambat Sabun Cair Cuci Tangan pada Restoran Waralaba di Kota Padang Terhadap Pertumbuhan Bakteri Escherichia coli dan Staphylococcus aureus Secara In Vitro

    Directory of Open Access Journals (Sweden)

    Anisha Fazlisia

    2014-09-01

    Full Text Available AbstrakSabun cair cuci tangan terbukti dapat menghambat pertumbuhan bakteri Escherichia coli dan Staphylococcus aureus. Sebagian besar restoran waralaba di Kota Padang menyediakan sabun cair cuci tangan yang telah diencerkan. Proses pengenceran mengubah kemampuan sabun dalam menghambat pertumbuhan bakteri. Penelitian bertujuan untuk menguji daya hambat sabun cair cuci tangan pada restoran waralaba di Kota Padang terhadap pertumbuhan E. coli dan S. aureus. Sampel diambil dari empat restoran waralaba dan diuji dengan metode difusi. Hasil penelitian menunjukkan bahwa keempat sabun dapat menghambat pertumbuhan S. aureus namun hanya sebagian yang memiliki daya hambat terhadap E. coli. Median daya hambat pertumbuhan E. coli dan S. aureus pada setiap periode yaitu 0, 7.4, 7.3 dan 0, 26.1, 23.3. Nilai maksimum daya hambat pertumbuhan E.coli dalam tiga periode yaitu 19.5, 35.4, 27.1 dan 20.7, 40.2, 36.6 untukS. aureus. Daya hambat minimum terhadap kedua bakteri adalah 0.00. Hal tersebut dapat dipengaruhi komposisi dan konsentrasi antiseptik, antibakteri, pH sabun, pengenceran dan struktur dinding sel bakteri. Disimpulkan bahwa sabun cair cuci tangan yang diuji memiliki kemampuan lebih besar dalam menghambat pertumbuhan S.aureus daripada E.coli.Kata kunci: sabun cair cuci tangan, restoran, pengenceran, uji daya hambat, pertumbuhan bakteriAbstractLiquid hand soaps proved to inhibit Escherichia coli and Staphylococcus aureus bacterial growth. In Padang, most of Restaurants provide diluted liquid hand soaps. Research found dilution changed soap ability to inhibit bacterial growth. The purpose of this study was to examine the ability of Padang City Restaurants’ liquid hand soaps to inhibit E. coli and S. aureus bacterial growth. The samples were taken from four restaurants and examined by using diffusion method. The results showed all of them could inhibit S. aureus but only a half inhibited Escherichia coli bacterial growth. Median for E. coli and S

  7. The BaBar Mini

    Energy Technology Data Exchange (ETDEWEB)

    Brown, David N.

    2003-07-11

    BaBar has recently deployed a new event data format referred to as the Mini. The mini uses efficient packing and aggressive noise suppression to represent the average reconstructed BaBar event in under 7 KBytes. The Mini packs detector information into simple transient data objects, which are then aggregated into roughly 10 composite persistent objects per event. The Mini currently uses Objectivity persistence, and it is being ported to use Root persistence. The Mini contains enough information to support detailed detector studies, while remaining small and fast enough to be used directly in physics analysis. Mini output is customizable, allowing users to both truncate unnecessary content or add content, depending on their needs. The Mini has now replaced three older formats as the primary output of BaBar event reconstruction. A reduced form of the Mini will soon replace the physics analysis format as well, giving BaBar a single, flexible event data format covering all its needs.

  8. A = Ba, Sr or Pb

    Indian Academy of Sciences (India)

    Unknown

    tion in the transmission mode. The samples were rotated ... The profiles were fitted using a pseudo-Voigt function. The Chebyshev ... Crystal data for ABi4Ti4O15 (A = Ba, Sr or Pb) at. 298 K. Formula. BaBi4Ti4O15. SrBi4Ti4O15. PbBi4Ti4O15. Formula weight. 1404⋅85. 1355⋅13. 1474⋅70. Colour. Yellow. Yellow. Yellow.

  9. PENGARUH KO-INFEKSI BAKTERI Streptococcus agalactiae DENGAN Aeromonas hydrophila TERHADAP GAMBARAN HEMATOLOGI DAN HISTOPATOLOGI IKAN TILAPIA ( Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Desy Sugiani

    2012-04-01

    Full Text Available Karakteristik hasil ko-infeksi buatan dari penyakit Streptococcosis dan MAS (Motile Aeromonas Septicemia dapat dilihat dengan menggunakan parameter gambaran hematologi dan histopatologi. Ikan tilapia (Oreochromis niloticus ukuran 15 g diinfeksi secara intra peritoneal dengan bakteri Streptococcus agalactiae dan Aeromonas hydrophila menggunakan dosis LD50. Perubahan pertahanan non spesifik ikan terhadap infeksi patogen dilihat dengan mengamati level hematokrit, neutrofil, limfosit, monosit, dan indeks fagositik darah ikan tilapia yang diambil dari arteri caudalis pada hari ke-3, 6, 9, 12, dan 15 setelah infeksi. Hasil analisis perubahan level hematokrit dan limfosit lebih tinggi dibandingkan dengan kontrol, level neutrofil lebih rendah dibandingkan dengan kontrol, dan level monosit dan indeks fagositik fluktuatif selama masa perlakuan memperlihatkan adanya homeostasi gambaran darah ikan terhadap serangan infeksi antigen. Hasil histopatologi organ ginjal, otak, hati, dan limfa memperlihatkan dua pola karakter luka. Pola pertama, luka yang focal sampai terlihat adanya inflamasi dan perdarahan. Pola kedua, luka yang multifocal, luka parah (acute, nekrotik, dan luka inflamasi yang mengakibatkan deformasi sel-sel organ.

  10. AKTIVITAS ANTIBAKTERI EKSTRAK KULIT KAYU AKWAY (Drimys piperita Hook f. TERHADAP BAKTERI PATOGEN (Antibacterial Activities of Akway (Drimys piperita Hook f. Bark Extracts on Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Gino Nemesio Cepeda

    2015-09-01

    dan heksan. Pengujian kapasitas antibakteri ekstrak dilakukan dengan menggunakan metode difusi agar terhadap empat spesies bakteri, yaitu   ATCC25922   ATCC10876   ATCC27853 dan   ATCC25923 Hasil menunjukkan bahwa konsentrasi dan tingkat keasaman mempengaruhi kapasitas antibakteri ekstrak etilasetat kulit kayu akway. Pemanasan pada suhu 100 C selama 25 menit dan kandungan garam sampai 5% tidak mempengaruhi kapasitas antimikroba ekstrak kulit kayu akway. Kata kunci: Akway, ekstrak, antibakteri, pemanasan, pH dan kandungan garam

  11. AHP 45: REVIEW: PHYUR BA

    Directory of Open Access Journals (Sweden)

    'Brug mo skyid འབྲུག་མོ་སྐྱིད། (Zhoumaoji 周毛吉

    2017-03-01

    Full Text Available Mkha' mo rgyal was born in Dgon gong ma Village, 'Ba' (Tongde County, Mtsho lho (Hainan Tibetan Autonomous Prefecture, Mtsho sngon (Qinghai Province. While attending the Tibetan Studies College of Mtsho sngon Nationalities University she began writing. In addition to editing and translating teaching materials for primary and secondary schools, she has also published short stories and poetry (Mkha' mo rgyal, 2015. Phyur ba is the first Tibetan women's novel (Robin 2016:86 and was recognized as an Outstanding Work by the Qinghai Writers Guild in 2014 (Duojiecairang and Limaoyou 2014. 1 The name, which translates as 'dried cheese' is a food eaten daily by many Tibetans. Made from fermented milk without cream, it is dried in the sun by women in pastoral areas. Both sweet and sour, phyur ba brings to mind the happiness and sadness, ups and downs, laughter and tears that life brings. ...

  12. Využití kombinace bakterií a řas pro čištění odpadních vod

    OpenAIRE

    Hlavsová, Barbora

    2014-01-01

    Cílem této bakalářské práce je seznámit čtenáře se stále se zdokonalujícími způsoby biologického čištění odpadních vod s využitím bakterií, řas a jejich kombinace. Dále také s velmi atraktivními možnostmi využití biomasy získané tímto čištěním v různých odvětvích, jako je energetika, chemie, farmacie a zemědělský průmysl. Druhá část této práce se týká technicko-ekonomické studie čištění odpadních vod s využitím kombinace bakterií a řas v konkrétní zadané lokalitě. The aim of this bachelor'...

  13. High spin properties of Ba

    Indian Academy of Sciences (India)

    Abstract. The 124Ba nucleus is investigated on the basis of the method of statistical mechanics by assuming the nucleons to move in triaxially deformed Nilsson potential. The variation in the Fermi energies of protons and neutrons is studied as a function of spin and temperature. The Fermi energies determined as a function ...

  14. TRANSITIVITY AND THE BA CONSTRUCTION

    Directory of Open Access Journals (Sweden)

    Pei-Jung Kuo

    2010-06-01

    Full Text Available In this paper, I discuss the legitimacy of positing a Transitivity Projection (= TrP cf. Bowers 1993, 1997, 2001 and 2002 in the BA construction in Mandarin Chinese. BA has been proposed to be a semantically-bleached verb, inserted in the v position (Huang 1997 and Lin 2001. Several pieces of evidence such as manner adverbial placement (cf. Huang, Li and Li 2009 and GEI-insertion (cf. Tang 2001 indicate that there must be a functional projection between the vP and VP to host the BA NP. I propose that a TrP is probably the most apt candidate for the XP. I also argue, in contrast to the proposal by Huang, Li and Li (2009, that the present proposal which employs a TrP captures most of the properties of the BA construction. A comparison with the structure of the BEI construction also shows that the TrP proposal fits into the general picture of current linguistic theory on transitive constructions without extra stipulations.

  15. Ba isotopic signature for early differentiation between Cs and Ba in natural fission reactors

    Science.gov (United States)

    Hidaka, Hiroshi; Gauthier-Lafaye, François

    2008-08-01

    Ba isotopic studies of the Oklo and Bangombé natural fission reactors in east Gabon provide information on the geochemical behavior of radioactive Cs ( 135Cs and 137Cs) in a geological medium. Large isotopic deviations derived from fissiogenic Ba were found in chemical leachates of the reactor uraninites. The fissiogenic Ba isotopic patterns calculated by subtracting the non-fissiogenic component are classified into three types that show different magnifications of chemical fractionation between Cs and Ba. In addition, the isotopic signatures of fissiogenic 135Ba, 137Ba and 138Ba suggest an early differentiation between Cs and Ba of less than 20 years after the production of fissiogenic Cs and Ba. On the other hand, only small excesses of 135Ba ( ɛ reactors by differentiation.

  16. Pemurnian Parsial dan Karakterisasi Enzim Xilanase dari Bakteri Laut Bacillus safencis strain LBF P20 Asal Pulau Pari Jakarta

    Directory of Open Access Journals (Sweden)

    Fitria Fitria

    2017-03-01

    Full Text Available Enzyme xylanase (EC 3.2.1.8 is widely used in various industrial  fields for the hydrolysis of xylan (hemicellulose into xylooligosaccharide and xylose. The aims of this study were to  conduct partial purification and characterization of xylanase from marine Bacillus safencis strain LBF P20 and to obtain the  xylooligosaccharide types from xylan hydrolysis by this enzyme.  Based on this research, the optimum time for enzyme production  occurred at 96 hours with the enzyme activity of 6.275 U/mL and  enzyme specific activity of 5.093 U/mg. The specific activities were  obtained from precipitation by amicon® ultra-15 centrifugal filter devices, gel filtration chromatography and anion exchange chromatography that were increased by 15.07, 34.7, and 96.0  U/mg. The results showed that the highest activity at pH 7, temperature of 60 °C, and stable at 4 °C. Type of  xylooligosaccharide produced by this study were xylohexoses, xylotriose, and xylobiose. SDS-PAGE analysis and zimogram  showed that the molecular weight of xylanase protein were about  25 kDa.   ABSTRAK Enzim xilanase (EC 3.2.1.8 digunakan dalam hidrolisis xilan  (hemiselulosa menjadi xilooligosakarida dan xilosa. Penelitian  ini bertujuan untuk melakukan purifikasi parsial dan karakterisasi xilanase dari bakteri laut Bacillus safencis strain LBF P20 serta uji  hidrolisis untuk mengetahui jenis xilooligosakarida yang  dihasilkan oleh enzim tersebut. Berdasarkan hasil penelitian, waktu optimum untuk produksi enzim terjadi pada jam ke 96  dengan aktivitas enzim sebesar 6,275 U/mL dan aktivitas spesifik enzim sebesar 5,093 (U/mg. Aktivitas spesifik enzim hasil  pemekatan dengan amicon® ultra-15 centrifugal filter devices,  kromatografi filtrasi gel dan kromatografi penukar anion  mengalami peningkatan berturut-turut sebesar 15,1; 34,7 dan96,0 U/mg. Hasil karakterisasi menunjukkan aktivitas  tertinggi pada pH 7, suhu 60 °C dan stabil pada suhu 4 °C. Analisis SDS

  17. SELEKSI BAKTERI ASAM LAKTAT DENGAN AKTIVITAS ANTI JAMUR YANG DIISOLASI DARI SILASE DAN SALURAN CERNA TERNAK (Isolation of Lactic Acid Bacteria for Antifungal Activity Isolated from Silage and Animal Digestives Tract

    Directory of Open Access Journals (Sweden)

    Ema Damayanti

    2015-09-01

    Pengujian aktivitas anti jamur dilakukan dalam secara kualitatif dengan metode dan secara kuantitatif dengan menguji daya hambat supernatan bebas sel menggunakan metode difusi kertas cakram terhadap kapang FNCC 6002,   FNCC 6033 dan   FNCC 6111. Hasil penelitian menunjukkan isolat PDS2 dari silase memiliki daya hambat yang nyata terhadap ketiga jamur uji, sedangkan isolat BAL dari saluran cerna unggas dan ruminansia tidak menunjukkan daya hambat yang nyata. Kata kunci: Anti jamur, bakteri asam laktat, saluran cerna ternak, silase

  18. PRODUKSI ENZIM SELULASE DARI BAKTERI TS2b YANG DIISOLASI DARI RUMPUT LAUT DAN PEMANFAATANNYA DALAM MENGHIDROLISIS KULIT UBI KAYU DAN DAUN UBI KAYU SEBAGAI BAHAN BAKU PAKAN IKAN Irma

    Directory of Open Access Journals (Sweden)

    Irma Melati

    2014-08-01

    mengingat makin meningkatnya harga pakan ikan. Salah satu bahan yang berpotensi untuk dimanfaatkan adalah kulit ubi kayu (KUK dan daun ubi kayu (DUK. Tingginya kadar serat kasar khususnya selulosa dalam bahan baku tersebut, menjadi kendala dalam upaya pemanfaatannya. Penggunaan enzim selulase dapat menjadi alternatif untuk menangani masalah tersebut. Kemampuan komplek enzim selulase dari bakteri selulolitik dalam mendegradasi selulosa sangat beragam. Tujuan penelitian ini adalah memproduksi dan memanfaatkan enzim selulase dari bakteri yang diisolasi dari rumput laut untuk menghidrolisis KUK, DUK, dan selulosa murni (Carboxymethyl Cellulose. Penelitian ini dilaksanakan dalam dua tahap yaitu: pertama adalah produksi optimum enzim selulase dari bakteri TS2b dengan waktu inkubasi 24, 48, 72, 78, dan 96 jam dan kedua adalah tahap untuk mengetahui kemampuan enzim selulase bakteri TS2b dalam menghidrolisis KUK, DUK, dan Carboxymethyl Cellulose (CMC (in vitro. Parameter yang diamati adalah aktivitas enzim selulase berdasarkan modifikasi metode Miller dan kadar gula pereduksi (glukosa berdasarkan metode DNS. Hasil penelitian menunjukkan bahwa waktu optimum untuk produksi enzim selulase terjadi pada jam ke-78 yaitu sebesar 0,0214 U/mL dengan kadar glukosa yang dilepaskan sebesar 0,0231 mg/L. Daya hidrolisis enzim selulase tertinggi diperoleh pada substrat KUK dengan aktivitas enzim selulase dan kadar gula pereduksi yang dilepaskan berturutturut sebesar 0,0179 U/mL dan 0,9701 mg/L; sedangkan daya hidrolisis terendah diperoleh pada substrat DUK dengan aktivitas selulase sebesar 0,0015 U/mL dan kadar gula pereduksi yang dilepaskan sebesar 0,0787 mg/L. Enzim selulase isolat TS2b mempunyai kemampuan menghidrolisis substrat KUK dengan baik, tapi kurang efektif untuk menghidrolisis CMC dan DUK.

  19. Thermodynamic study of BaCuO2 and BaCu2O2

    Science.gov (United States)

    Shimpo, Ryokichi; Nakamura, Yasushi

    1994-06-01

    The Gibbs energy changes for the syntheses of the interceramic compounds of BaCuO2 and BaCu2O2 were investigated as a basic study in the Y-Ba-Cu-O system that includes a superconductor, YBa2Cu3O6.5+ x . For the compound BaCuO2, thermogravimetry with CO2-O2-N2 gas mixtures was employed, and equilibrium temperatures were determined at which CO2 partial pressures in the gas mixtures were equilibrated with mixed powder of BaCuO2, CuO, and BaCO3. The Gibbs energy change for the reaction of BaCO3 + CuO = BaCuO2 + CO2 was determined from the relation between CO2 partial pressure and equilibrium temperature, taking into consideration the effect of CO2 dissolution in BaCuO2. For the study on BaCu2O2, electromotive force (emf) measurement using yttria-stabilized zirconia solid electrolyte was conducted. A technique using two cells was applied to the emf measurement for minimizing the effect of dispersion of oxygen from samples, and the Gibbs energy change for the reaction of BaCuO2 + CuO = BaCu2O2 + 1/2O2 was decided from the measured O2 partial pressure.

  20. BaBar Data Aquisition

    CERN Document Server

    Scott, I; Grosso, P; Hamilton, R T; Huffer, M E; O'Grady, C; Russell, J J

    1998-01-01

    The BaBar experiment at the Stanford Linear Accelerator Center is designed to perform a search for CP violation by analysing the decays of a very large sample of B and Bbar mesons produced at the high luminosity PEP-11 accelerator. The data acquisition system must cope with a sustained high event rate, while supporting real time feature extraction and data compression with minimal dead time. The BaBar data acquisition system is based around a common VME interface to the electronics read-out of the separate detector subsystems. Data from the front end electronics is read into commercial VME processors via a custom "personality card" and PCI interface. The commercial CPUs run the Tornado operating system to provide a platform for detector subsystem code to perform the necessary data processing. The data are read out via a non-blocking network switch to a farm of commercial UNIX processors. Careful design of the core data acquisition code has enabled us to sustain events rates in excess of 20 kHz while maintaini...

  1. Perbandingan Efektivitas Daya Hambat Kotrimoksazol Generik dan Paten terhadap Pertumbuhan Bakteri Escherichia coli sebagai Penyebab Infeksi Saluran Kemih secara In Vitro

    Directory of Open Access Journals (Sweden)

    Puti Anggun Sari

    2015-01-01

    Full Text Available AbstrakInfeksi saluran kemih merupakan salah satu infeksi yang sering ditemukan setelah infeksi saluran napas. Penyebab terbanyak infeksi saluran kemih adalah Escherichia coli. Kotrimoksazol merupakan kombinasi dari dua obat yaitu trimetoprim dan sulfametoksazol serta salah satu contoh antibiotik yang merupakan first-line therapy untuk infeksi saluran kemih. Kotrimoksazol terbagi menjadi dua jenis obat yaitu obat generik dan paten. Akan tetapi, belakangan ini penggunaan obat generik mulai menurun di masyarakat dan masyarakat cenderung meragukan kualitasnya. Padahal masyarakat yang akan diuntungkan jika mengetahui mutu obat generik tidak kalah dengan obat paten. Tujuan dari penelitian ini adalah untuk membandingkan efektivitas daya hambat kotrimoksazol generik dan paten terhadap pertumbuhan bakteri Escherichia coli sebagai penyebab infeksi saluran kemih secara in vitro. Penelitian ini merupakan penelitian analitik eksperimental dengan desain cross-sectional study. Penelitian ini menggunakan 19 sampel isolat bakteri dari pasien infeksi saluran kemih yang disebabkan oleh Escherichia coli di RSUP Dr. M. Djamil yang ditentukan rumus minimal adequate sample size menggunakan metode difusi cakram dan dilihat perbandingan antara zona bebas kuman yang dibentuk oleh obat generik dan paten tersebut. Data yang diperoleh akan diolah secara statistik dengan uji hipotesis t-independent test. Hasil penelitian menunjukkan bahwa pada 17 sampel tidak didapatkan zona bebas kuman baik pada kotrimoksazol generik atau paten. Sedangkan pada 2 sampel lainnya didapatkan zona bebas kuman pada kedua obat kotrimoksazol generik dan paten. Setelah dilakukan analisis statistik menggunakan SPSS dengan uji t-independent test didapatkan bahwa tidak terdapat perbedaan bermakna antara sensitivitas bakteri Escherichia coli penyebab infeksi saluran kemih terhadap kotrimoksazol generik dan paten. Sedangkan resistensi yang terjadi pada 17 sampel lain diduga disebabkan penggunaan

  2. Bakterier og biopolitik

    DEFF Research Database (Denmark)

    Jørgensen, Jens Lohfert

    2017-01-01

    Around the year 1900, a number of prominent authors depict a changing world, phenomenologically and psychologically, as well as socially and politically, via bacteria. This endeavor moves their work in the direction of modernism. Drawing on Robert Esposito’s work on the interrelations between bio...... biopolitics, community and immunity, and on Jane Bennett’s notion of “vibrant matter”, this article discusses one of these works, Joseph Conrad’s 1897 novel The Nigger of the ‘Narcissus’, focusing on its depiction of social dynamics and the material anchorage of these dynamics....

  3. Bakterier, bomber og bistand

    DEFF Research Database (Denmark)

    Seeberg, Jens

    2008-01-01

    En epidemi er ikke en naturgiven enhed, men et fænomen som defineres af den statistisk baserede ekspertviden, som epidemiologien kan levere. Epidemien er per definition et socialt (modsat individuelt) fænomen, og det er et politisk ladet fænomen. Epidemier er genstand for samfundsmæssige interven......En epidemi er ikke en naturgiven enhed, men et fænomen som defineres af den statistisk baserede ekspertviden, som epidemiologien kan levere. Epidemien er per definition et socialt (modsat individuelt) fænomen, og det er et politisk ladet fænomen. Epidemier er genstand for samfundsmæssige...

  4. Infeksi Biofilm Bakterial

    OpenAIRE

    Homenta, Heriyannis

    2016-01-01

    : Biofilm is the unity of microbial cell surface surrounded by a matrix of extracellular polymeric substances (EPS). Bacteria composing the biofilm are heterogeneous in space and time. This biofilm continues to grow influenced by internal and external processes. Moreover, biofilm can be found on the surface of medical devices, as well as in bacterial endocarditis and cystic fibrosis. Biofilm that is already formed can lead to antibiotic resistance.

  5. AKTIVITAS KITINASE, LESITINASE, DAN HEMOLISIN ISOLAT DARI BAKTERI IKAN NILA (Oreochromis niloticus Lin. YANG DIKULTUR DALAM KERAMBA JARING APUNG WADUK JATILUHUR, PURWAKARTA

    Directory of Open Access Journals (Sweden)

    Wibowo Mangunwardoyo

    2016-11-01

    Full Text Available Aeromonas hydrophila Lin. merupakan bakteri patogen oportunistik akuatik yang virulensinya dipengaruhi oleh adanya enzim kitinase, lesitinase, dan toksin haemolisin, merupakan penyebab kematian ikan nila yang tinggi. Penelitian bertujuan untuk mengamati aktivitas enzim kitinase, lesitinase, dan toksin hemolisin dari 30 ikan nila dari keramba jaring apung waduk Jatiluhur dengan metode tehnik agar. A. hydrophila menunjukkan positif virulen ditunjukkan adanya zona bening untuk lesitinase sebesar 7,9 mm; kitinase 8,0 mm; dan hemolisin 6,6 mm dibandingkan dengan isolat Enterobacter sp., Pseudomonas sp., dan Vibrio sp. Hal ini menunjukkan bahwa A. hydrophila bersifat patogen dan virulen terhadap ikan nila. Aeromonas hydrophila Lin. is one of opportunistic aquatic pathogen bacteria where its pathogenic behavior is influenced by chitinase, lechitinase, and toxin haemolycine, and causes high mortality in nile tilapia culture. The purpose of the research was to observe the activities of two A. hydrophila’s enzymes i.e.: chitinase and lechitinase, and one extracelullar toxin, haemolycine, isolated from 30 nile tilapias cultured in floating net cage at Jatiluhur using quantitative plate assay technique. A. hydrophila was positive virulent marked with transparent zone of lechitinase of 7.9 mm, haemolycin of 6.6 mm, and chitinase of 8.0 mm compared to Enterobacter sp., Pseudomonas sp., and Vibrio sp. Therefore, A. hydrophila is determined as highly pathogenic bacterium and virulent for nile tilapia.

  6. 134Ba diffusion in polycrystalline BaMO3 (M = Ti, Zr, Ce)

    Science.gov (United States)

    Sažinas, Rokas; Sakaguchi, Isao; Einarsrud, Mari-Ann; Grande, Tor

    2017-11-01

    Cation diffusion in functional oxide materials is of fundamental interest, particularly in relation to interdiffusion of cations in thin film heterostructures and chemical stability of materials in high temperature electrochemical devices. Here we report on 134Ba tracer diffusion in polycrystalline BaMO3 (M = Ti, Zr, Ce) materials. The dense BaMO3 ceramics were prepared by solid state sintering, and thin films of 134BaO were deposited on the polished pellets by drop casting of an aqueous solution containing the Ba-tracer. The samples were subjected to thermal annealing and the resulting isotope distribution profiles were recorded by secondary ion mass spectrometry. The depth profiles exhibited two distinct regions reflecting lattice and grain boundary diffusion. The grain boundary diffusion was found to be 4-5 orders of magnitude faster than the lattice diffusion for all three materials. The temperature dependence of the lattice and grain boundary diffusion coefficients followed an Arrhenius type behaviour, and the activation energy and pre-exponential factor demonstrated a clear correlation with the size of the primitive unit cell of the three perovskites. Diffusion of Ba via Ba-vacancies was proposed as the most likely diffusion mechanism.

  7. EFEKTIVITAS GEL ANTIJERAWAT EKSTRAK METANOL DAUN PACAR AIR (Impatiens balsamina L. TERHADAP BAKTERI Propionibacterium acnes dan Staphylococcus epidermidis SECARA IN VITRO

    Directory of Open Access Journals (Sweden)

    Septira Murtiningsih

    2014-06-01

    Full Text Available Propionibacterium acnes dan Staphylococcus epidermidis is an inflamation triggering bacterias in acne vulgaris. Plants that has been studied for antibacterial effect is Impatiens balsamina. Gel bases for acnes therapy are hydrophilic bases like HPMC (Hydroxypropyl methylcellulose and carbopol. The aim of this study was to know the optimum combination of Carbopol and HPMC (Hydroxypropyl metylcellulose in gel formulation that gives best antibacterial effect and to evaluate physical and chemical properties of gel. Extraction was performed by soxhlet method with methanol as solvent. The design of optimum gel formulation was performed using simplex lattice design. Optimum gel formulation was combination of 21% HPMC and 79% Carbopol. Verification results showed that optimum gel of inhibition zone of P. acnes and S. epidermidis is 17.61±0.93 mm and 16.01±1.01 mm respectively. Positive control compared to optimum gel showed inhibition zone toward P.acnes and S.epidermidis of 29.1±1.34 mm and 24.98±1.83 mm respectively. Analysis results using T-test showed that p-value was lower than 0.05 (p<0.05 hence the effectivity from optimum gel was significantly different from positive control that has greater activity than optimum gel. Evaluation of optimum gel showed gel has dark brown color, specific odor from extract, adhesive force of 3.17 minutes, spreadibility of 32.69 cm2, viscosity of 436.66 cP and as well as the pH of 5.23. Keywords: Methanolic extracts of Impatiens balsamina leaves, Propionibacterium acnes, Staphylococcus epidermidis, gel, carbopol, HPMC   ABSTRAK Propionibacterium acnes dan Staphylococcus epidermidis adalah bakteri pemicu peradangan pada jerawat. Tanaman yang telah banyak diteliti sebagai antibakteri adalah pacar air (Impatiens balsamina L.. Bahan dasar gel yang cocok untuk terapi jerawat adalah bahan dasar hidrofilik seperti HPMC (Hydroxypropyl methylcellulose dan karbopol. Tujuan dari penelitian ini adalah untuk mengetahui

  8. Antibacterial Activity Test of Nudibranches Polka - Dot (Jorunna funebris (Gastropods : Molusc Extract Against Multi(Aktivitas Antibakteri Ekstrak Nudibranch Polka-Dot (Jorunna funebris (Gastropoda : Moluska Terhadap Bakteri Multidrug Resistant (MDR

    Directory of Open Access Journals (Sweden)

    Delianis Pringgenies

    2015-12-01

    Full Text Available Terjadinya resistensi antibiotik menjadi permasalahan dalam dunia kesehatan. Peningkatan kemampuan patogen dalam menahan efek obat menyebabkan timbulnya resistensi. Beberapa bakteri patogen pada manusia dilaporkan telah mengalami resistensi terhadap lebih dari satu kelas antibiotik. Untuk mengatasi permasalahan tersebut, maka perlu dilakukan pencarian senyawa antibiotik baru yang lebih efektif dalam mengatasi permasalahan bakteri Multi-drug Resistant (MDR. Metabolit sekunder yang diproduksi oleh invertebrata laut  mempunyai prospek sebagai bahan obat dari laut. Nudibranch diduga mampu menghasilkan metabolit sekunder sebagai mekanisme pertahanan diri. Tujuan dari penelitian ini adalah untuk mengetahui fraksi dari ekstrak nudibranch Jorunna funebris yang menunjukkan bioaktivitas terhadap bakteri Multi-drug Resistant (MDR. Proses ekstraksi dilakukan dengan metode maserasi. Fraksinasi dengan Kromatografi Kolom Terbuka (KKT. Uji aktivitas antibakteri menggunakan metode difusi agar. Analisis komponen senyawa dengan GC-MS. Hasil penelitian menunjukkan bahwa 8 fraksi ekstrak nudibranch J. funebris menunjukkan aktivitas antibakteri. Hasil uji aktivitas menunjukkan fraksi I paling aktif terhadap 5 bakteri uji yaitu Klebsiella, Pseudomonas, Escherichia coli, Enterobacter 5 dan Enterobacter 10 dengan rata-rata zona hambatan secara berurutan sebesar 12,78 mm; 12,51 mm; 15,47 mm; 14,09 mm dan 12,46 mm. Fraksi II paling aktif terhadap bakteri Coagulase Negative Staphylococcus dengan rata-rata zona hambatan sebesar 12,70 mm. Analisis GC-MS menunjukkan bahwa dalam fraksi II terdapat senyawa 1-oktadekanol yang berpotensi sebagai antibakteri. Kata kunci : nudibranch, Jorunna funebris, antibakteri, multi-drug resistant, 1-oktadekanol Emergence of antibiotic resistance become a problems on medical world. Increasing pathogen ability to hold the antibiotic effect caused resistance. Several human-patogen bacteria were resistance to one or more classes of antibiotics

  9. High spin properties of 124 Ba

    Indian Academy of Sciences (India)

    The 124Ba nucleus is investigated on the basis of the method of statistical mechanics by assuming the nucleons to move in triaxially deformed Nilsson potential. The variation in the Fermi energies of protons and neutrons is studied as a function of spin and temperature. The Fermi energies determined as a function of ...

  10. Magnetic comparison of BaCa and BaSr substituted hexaferrite powders

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Angeles, A [Alvaro Gonzalez-Angeles, Facultad de IngenierIa, Universidad Autonoma de Baja California, (UABC), Blvd. Benito Juarez s/n, Cp 21280 Mexicali, B. C. (Mexico); Lipka, J; Gruskova, A; Slama, J; Jancarik, V; Slugen, V, E-mail: gangelesa@yahoo.com.m [Faculty of Electrical Engineering and Information Technology, (FEEIT), Slovak University of Technology, (SUT), Ilkovicova 3, 812 19 Bratislava (Slovakia)

    2010-03-01

    Results on magnetic studies of Ba{sub 0.5}Sr{sub 0.5}Fe{sub 12-2x}(ZnTi){sub x}O{sub 19} and Ba{sub 0.75}Ca{sub 0.25}Fe{sub 12-2x}(ZnTi){sub x}O{sub 19}, where x = 0.2 to 0.6, ferromagnetic powders prepared by mechanical alloying are discussed. The structural and magnetic properties of the resulting powders were analyzed by thermo-magnetic analysis, X-ray diffraction, scanning electron microscopy, Moessbauer spectroscopy and magnetic measurements. Curie temperature, T{sub c} decreased dramatically (drop {approx} 39%) for BaCa samples, whilst for BaSr samples remained almost without change (diminution {approx} 2%) at x {<=} 0.2. SEM studies showed that all the particles present nearly hexagonal platelet shape.

  11. Spectroscopy of Ba and Ba$^+$ deposits in solid xenon for barium tagging in nEXO

    CERN Document Server

    Mong, B; Walton, T; Chambers, C; Craycraft, A; Benitez-Medina, C; Hall, K; Fairbank, W; Albert, J B; Auty, D J; Barbeau, P S; Basque, V; Beck, D; Breidenbach, M; Brunner, T; Cao, G F; Cleveland, B; Coon, M; Daniels, T; Daugherty, S J; DeVoe, R; Didberidze, T; Dilling, J; Dolinski, M J; Dunford, M; Fabris, L; Farine, J; Feldmeier, W; Fierlinger, P; Fudenberg, D; Giroux, G; Gornea, R; Graham, K; Gratta, G; Heffner, M; Hughes, M; Jiang, X S; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Krucken, R; Kuchenkov, A; Kumar, K S; Leonard, D S; Licciardi, C; Lin, Y H; Ling, J; MacLellan, R; Marino, M G; Moore, D; Odian, A; Ostrovskiy, I; Piepke, A; Pocar, A; Retiere, F; Rowson, P C; Rozo, M P; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Twelker, K; Vuilleumier, J -L; Walton, J; Weber, M; Wen, L J; Wichoski, U; Yang, L; Yen, Y -R; Zhao, Y B

    2014-01-01

    Progress on a method of barium tagging for the nEXO double beta decay experiment is reported. Absorption and emission spectra for deposits of barium atoms and ions in solid xenon matrices are presented. Excitation spectra for prominent emission lines, temperature dependence and bleaching of the fluorescence reveal the existence of different matrix sites. A regular series of sharp lines observed in Ba$^+$ deposits is identified with some type of barium hydride molecule. Lower limits for the fluorescence quantum efficiency of the principal Ba emission transition are reported. Under current conditions, an image of $\\le10^4$ Ba atoms can be obtained. Prospects for imaging single Ba atoms in solid xenon are discussed.

  12. Thermodynamic study of BaCuO[sub 2] and BaCu[sub 2]O[sub 2

    Energy Technology Data Exchange (ETDEWEB)

    Shimpo, Ryokichi; Nakamura, Yasushi (Univ. of Tokyo (Japan). Faculty of Engineering)

    1994-06-01

    The Gibbs energy changes for the syntheses of the interceramic compounds of BaCuO[sub 2] and BaCu[sub 2]O[sub 2] were investigated as a basic study in the Y-Ba-Cu-O system that includes a superconductor, YBa[sub 2]Cu[sub 3]O[sub 6.5+x]. For the compound BaCuO[sub 2], thermogravimetry with CO[sub 2[minus

  13. Pertumbuhan Bakteri Laut Shewanella indica LBF-1-0076 dalam Naftalena dan Deteksi Gen Naftalena Dioksigenase - (The Growth of Marine Bacteria Shewanella indica LBF-1-0076 in Naphthalene and Naphthalene dioxygenase Gene Detection

    Directory of Open Access Journals (Sweden)

    Nuzul Farini

    2017-06-01

    Full Text Available Crude oil exploitation which often occured offshore can cause water pollution in the sea since its contains naphthalene which is a hazardous compounds. This research used marine bacteria LBF-1-0076 that have ability in naphthalene degradation. This research aimed to study the parameter effect of naphthalene and cell concentration toward marine bacteria LBF-1-0076. This research also identified isolate LBF-1-0076 and detected the encode gene of naphthalene dioxygenase. Based on growth test result, the optimum naphthalene degradationby isolate LBF-1-0076 occured in 75 ppm naphthalene concentration with 15cell concentration. The result of 16S rDNA gene analysis showed that LBF-1-0076 was identified as Shewanella indica strain 0102 with identical value 99%. The result of naphthalene dioxygenase gene detection using Polymerase Chain Reaction (PCR showed that the isolate contained naphthalene dioxygenase gene with size ±377 bp. Therefore, LBF-1-0076 potential as bioremediation agent to solve crude oil contamination in the sea.Keywords:   crude oil, marine bacteria, naphthalene, naphthalene dioxygenase, Shewanella indicaABSTRAKEksploitasi minyak bumi yang sering terjadi di laut mengakibatkan adanya pencemaran minyak di laut. Naftalena merupakan salah satu senyawa dominan berbahaya yang terkandung dalam minyak bumi dan dapat mengakibatkan pencemaran perairan. Penelitian ini menggunakan bakteri laut LBF-1-0076 yang memiliki kemampuan untuk mendegradasi naftalena. Tujuan dari penelitian ini adalah mempelajari pengaruh parameter konsentrasi naftalena dan konsentrasi sel terhadap bakteri laut pendegradasi naftalena LBF-1-0076. Penelitian ini juga bertujuan untuk mengidentifikasi isolat LBF-1-0076 dan mendeteksi gen pengkode naftalena dioksigenase. Berdasarkan hasil uji pertumbuhan, degradasi naftalena yang optimal oleh isolat LBF-1-0076 terjadi pada konsentrasi naftalena 75 ppm dengan konsentrasi sel 15. Hasil analisis gen 16S rDNA menunjukkan isolat LBF

  14. Hadron Physics in BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Lafferty, G.D.; /Manchester U.

    2005-08-29

    Some recent results in hadron physics from the BaBar experiment are discussed. In particular, the observation of two new charmed states, the D*{sub sJ}{sup +}(2317) and the D*{sub sJ}{sup +}(2457), is described, and results are presented on the first measurement of the rare decay mode of the B meson, B{sup 0} {pi}{sup 0}{pi}{sup 0}.

  15. Farklı Işınlama Dozlarının Hamburger Köftelerde E. coli ve Toplam Mezofilik Aerobik Bakteri Üzerine Etkileri

    Directory of Open Access Journals (Sweden)

    Ayça Aylangan

    2015-02-01

    Full Text Available Bu çalışmada, ülkemizde önemli bir tüketim potansiyeli olan, özellikle ayaküstü yenilen gıdalar olarak adlandırılan fast food zincirlerinde yüksek miktarda tüketilen hamburger köftelerin muhafazası amacıyla ışınlama teknolojisi kullanılmıştır. Bu amaçla, dana kıymasından % 0.8 oranında NaCl içeren hamburger köfteleri üretilmiştir. Hamburger köfteleri iki gruba ayrılmış, bir grup E. coli ATCC 25922 suşu ile aşılanırken, diğer grup aşılanmamıştır. İki farklı depolama sıcaklığında ve süresinde (+4 °C’de 8 gün ve -12 °C’de 30 gün, ürünün mikrobiyel güvenlik ve kalitesinin sağlanması amacıyla uygulanan 3 farklı ışınlama dozunun (0.4 kGy; 0.8 kGy ve 1.2 kGy toplam mezofilik aerobik bakteri (TMAB sayısı ve Escherichia coli üzerine etkisi incelenmiştir. Yapılan çalışma sonunda, E. coli için D10 değeri 0.55 kGy olarak bulunmuştur. E. coli aşılanmamış hamburger örneklerinde gerçekleştirilen sayım sonuçlarına göre, 1.2 kGy doz uygulanmasının TMAB sayısında 2 log düzeyinde bir azalmaya yol açtığı belirlenmiştir.

  16. The BaBar Data Acquisition System

    CERN Document Server

    Scott, I; Grosso, P; Huffer, M E; O'Grady, C; Russell, J J

    1999-01-01

    The BaBar experiment at the Stanford Linear Accelerator Center is designed to perform a search for CP violation by ana-lyzing the decays of a very large sample of B and B(Bar) mesons produced at the high luminosity PEP-II accelerator. The data acquisition system must cope with a sustained high event rate, while supporting real time feature extraction and data compression with minimal dead time. The BaBar data acquisition system is based around a common VME interface to the electronics read-out of the separate detec-tor subsystems. Data from the front end electronics is read into commercial VME processors via a custom "Personality Card" and PCI interface. The commercial CPUs run the Tornado operating system to provide a platform for detector subsystem code to perform the necessary data processing. The data is read out via a non-blocking network switch to a farm of commercial UNIX processors. The current implementation of the BaBar data acquisition sys-tem has been shown to sustain a Level 1 trigger rate of 1.3...

  17. New Spectroscopy at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Mazzoni, M.A.; /INFN, Rome

    2007-04-18

    The Babar experiment at the SLAC B factory has accumulated a high luminosity that offers the possibility of systematic studies of quarkonium spectroscopy and of investigating rare new phenomena. Recent results in this field are presented. In recent times spectroscopy has become exciting again, after the discovery of new states that are not easily explained by conventional models. States such as the X(3872) and the Y(4260) could be new excited charmonium states, but require precise measurements for positive identification. The BaBar experiment [1] is installed at the asymmetric storage ring PEP-II. 90% of the data accumulated by BaBar are taken at the Y(4S) (10.58 GeV) and 10% just below (10.54 GeV). The BaBar detector includes a 5-layer, double-sided silicon vertex tracker and a 40-layer drift chamber in a 1.5 T solenoidal magnetic field, which detect charged particles and measures their momenta and ionization energy losses. Photons, electrons, and neutral hadrons are detected with a CsI(Tl)-crystal electromagnetic calorimeter. An internally reflecting ring-imaging Cherenkov is also used for particle id. Penetrating muon and neutral hadrons are identified by an array of resistive-plate chambers embedded in the steel of the flux return. The detector allows good track and vertex resolution, good particle id and good photon detection so it is especially suited for spectroscopy studies.

  18. PENGGUNAAN EKSTRAK DAUN SIRIH (Piper betle Linn UNTUK MENGHAMBAT BAKTERI Aeromonas hydrophila DAN TOKSISITASNYA PADA IKAN PATIN (Pangasius hypophthalmus (THE USE OF PIPER BETLE LINN EXTRACT ON AEROMONAS HYDROPHILA TO OBSTRUCT AND THE TOKSISITY TO PANGASIUS HYPOPHTHALMUS

    Directory of Open Access Journals (Sweden)

    Siti Aisiah

    2016-06-01

    Full Text Available Tujuan penelitian ini untuk mengetahui   daya  hambat  daun  sirih   yang  paling  besar  terhadap  bakteri Aeromonas Hydrophila, mengetahui konsentrasi minimal ekstrak daun sirih yang mampu menghambat pertumbuhan bakteri  A. hydrophila  dan mengetahui toksisitas konsentrasi efektif dari  ekstrak daun sirih terhadap ikan patin. Rancangan percobaan yang digunakan untuk  uji toksisitas  adalah rancangan acak lengkap, terdiri dari 4 perlakuan yaitu A  = Ikan disuntik dengan ekstrak daun sirih konsentrasi 75%, B  = Ikan disuntik dengan ekstrak daun sirih konsentrasi 25%, C  = Kontrol positif (ikan disuntik dengan akuades steril dan D  = Kontrol negatif (ikan tidak disuntik, diulang 3 kali. Hasil uji sensitivitas antibakteri daun sirih yang mempunyai daya hambat dan daya bunuh paling besar terhadap bakteri A. hydrophila adalah ekstrak daun sirih-metanol. Pengujian MIC menunjukkan bahwa ekstrak daun sirih-metanol memiliki daya hambat minimal 25 % terhadap aktivitas bakteri A. hydrophila. Hasil uji toksisitas yang dilakukan terhadap ikan patin dengan konsentrasi 75% dan 25% menunjukkan bahwa mortalitas yang terjadi tidak mencapai 50%. Pengamatan hematologis pada masing-masing perlakuan menunjukkan hasil yang berpengaruh tidak nyata terhadap kesehatan ikan patin. Parameter kualitas air pada penelitian ini yaitu, , kadar oksigen terlarut,  pH, amoniak, CO2 dan suhu masih dapat mendukung kehidupan ikan patin. This research was aimed a finding the part of Piper betle Linn  which had the biggest resistance to Aeromonas hydrophila bacteria and to know the minimal concentrate which could obstruct the growth of A. hydrophila  bacteria and to know effective concentrate toxicity of P. betle Linn  to Pangasius hypophthalmus.  The random sampling used proportionate stratified random sampling. In toxicity test, it had be done 4 treatment, which was given to fish, those were : A = fish was injected with 25 % concentrate of extract  P

  19. Uji Efek Antibakteri Minyak Jintan Hitam (Nigella Sativa Dalam Kapsul yang Dijual Bebas Selama Tahun 2012 di Kota Padang Terhadap Bakteri Staphylococcus aureus dan Escherichia coli Secara In Vitro

    Directory of Open Access Journals (Sweden)

    Gezha Utama Putra

    2015-05-01

    Full Text Available AbstrakJintan Hitam atau Nigella sativa diketahui memiliki kemampuan sebagai antibakteri, seperti terhadap Staphylococcus aureus dan Escherichia coli. Kedua bakteri ini memiliki sifat yang berbeda namun memiliki kesamaan dari penyakit yang disebabkannya. Tujuan penelitian ini adalah untuk membandingkan efek antibakteri produk minyak jintan hitam (Nigella sativa dalam bentuk kapsul antara bakteri Staphylococcus aureus dan Escherechia coli secara in vitro. Penelitian ini dilakukan pada bulan Januari 2012 - Desember 2012 di Laboratorium Mikrobiologi, Fakultas Kedokteran Universitas Andalas. Penelitian ini menunjukkan bahwa semua sampel jintan hitam yang digunakan tidak memiliki efek antibakteri terhadap Escherichia coli dan semua sampel tersebut memiliki efek antibakteri yang bervariasi pada Staphylococcus aureus. Analisis Anova menunjukkan bahwa masing-masing sampel minyak Nigella sativa memberikan efek berbeda secara signifikan pada pertumbuhan Staphylococcus aureus, bahkan enam diantaranya memiliki efek yang lebih baik daripada Cepoperazon (25 mm sebagai kontrol yang digunakan.Kata kunci: Nigella sativa, efek antibakteri, Staphylococcus aureus, Escherichia coli. AbstractBlack Cumin or Nigella sativa known have the capability as antibacterial, such as to Staphylococcus aureus and Escherichia coli. Both of these bacteria have different properties but have similarities from diseases they may cause. The objective of this study was to compare anti-bacterial effects of black cumin oil (Nigella sativa which has been packaged in capsules towards Staphylococcus aureus and Escherichia coli in vitro The research was conducted in January 2012 to December 2012 at the Microbiology laboratory, Medicine Faculty of Andalas University. The results of this research indicate that all black cumin samples that are used did not have antibacterial effect against Escherichia coli and all samples had antibacterial effects on Staphylococcus aureus with germ-free area

  20. Geoenvironmental weathering/deterioration of landfilled MSWI-BA glass.

    Science.gov (United States)

    Wei, Yunmei; Saffarzadeh, Amirhomayoun; Shimaoka, Takayuki; Zhao, Chun; Peng, Xuya; Gao, Junmin

    2014-08-15

    Municipal solid waste incineration bottom ash (MSWI-BA) glass serves as a matrix of assorted bottom ash (BA) compounds. Deterioration of the BA glass phases is quite important as they regulate the distribution of a series of toxic elements. This paper studied landfilled MSWI-BA samples from the mineralogical and geochemical viewpoint to understand the deterioration behavior of the BA glass phases as well as mechanisms involved. Bulk analysis by PXRD as well as micro-scale analysis by optical microscopy and SEM/EDX was conducted for such purposes. The results revealed that dissolution of the BA glass phases has resulted in a deterioration layer of 10(0)-10(2)μm thickness after years of disposal. This rapid weathering process is highly relevant to the specific glass characteristics and solution pH. The BA glass phases with more embedded compounds and cracks/fissures tend to be more vulnerable. Moreover, the generally alkaline pH in ash deposit favors a rapid disruption of the glass phase. The weathering products are mainly gel phases (including Al-Si gel, Ca-Al-Si gel, Fe-Al-Si gel etc.) with iron oxide/hydroxide as accessory products. Breakdown of the BA glass phases triggers chemical evolution of the embedded compounds. Based on all the findings above, a model is proposed to illustrate a general evolution trend for the landfilled MSWI-BA glass phases. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Syntheses and crystal structures of BaAgTbS{sub 3}, BaCuGdTe{sub 3}, BaCuTbTe{sub 3}, BaAgTbTe{sub 3}, and CsAgUTe{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Jai; Beard, Jessica C.; Ibers, James A. [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113 (United States); Mesbah, Adel [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113 (United States); ICSM-UMR 5257 CNRS/CEA/UM2/ENSCM, Bat 426, BP 17171, 30207 Bagnols/Ceze (France)

    2015-06-15

    Five new quaternary chalcogenides of the 1113 family, namely BaAgTbS{sub 3}, BaCuGdTe{sub 3}, BaCuTbTe{sub 3}, BaAgTbTe{sub 3}, and CsAgUTe{sub 3}, were synthesized by the reactions of the elements at 1173-1273 K. For CsAgUTe{sub 3} CsCl flux was used. Their crystal structures were determined by single-crystal X-ray diffraction studies. The sulfide BaAgTbS{sub 3} crystallizes in the BaAgErS{sub 3} structure type in the monoclinic space group C{sup 3},{sub 2h}-C2/m, whereas the tellurides BaCuGdTe{sub 3}, BaCuTbTe{sub 3}, BaAgTbTe{sub 3}, and CsAgUTe{sub 3} crystallize in the KCuZrS{sub 3} structure type in the orthorhombic space group D{sup 1},{sub 2}{sup 7},{sub h}-Cmcm. The BaAgTbS{sub 3} structure consists of edge-sharing [TbS{sub 6}{sup 9-}] octahedra and [AgS{sub 5}{sup 9-}] trigonal pyramids. The connectivity of these polyhedra creates channels that are occupied by Ba atoms. The telluride structure features {sup 2}{sub ∞}[MLnTe{sub 3}{sup 2-}] layers for BaCuGdTe{sub 3}, BaCuTbTe{sub 3}, BaAgTbTe{sub 3}, and {sup 2}{sub ∞}[AgUTe{sub 3}{sup 1-}] layers for CsAgUTe{sub 3}. These layers comprise [MTe{sub 4}] tetrahedra and [LnTe{sub 6}] or [UTe{sub 6}] octahedra. Ba or Cs atoms separate these layers. As there are no short Q..Q (Q = S or Te) interactions these compounds achieve charge balance as Ba{sup 2+}M{sup +}Ln{sup 3+}(Q{sup 2-}){sub 3} (Q = S and Te) and Cs{sup +}Ag{sup +}U{sup 4+}(Te{sup 2-}){sub 3}. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Co2FeAl based magnetic tunnel junctions with BaO and MgO/BaO barriers

    Directory of Open Access Journals (Sweden)

    J. Rogge

    2015-07-01

    Full Text Available We succeed to integrate BaO as a tunneling barrier into Co2FeAl based magnetic tunnel junctions (MTJs. By means of Auger electron spectroscopy it could be proven that the applied annealing temperatures during BaO deposition and afterwards do not cause any diffusion of Ba neither into the lower Heusler compound lead nor into the upper Fe counter electrode. Nevertheless, a negative tunnel magnetoresistance (TMR ratio of -10% is found for Co2FeAl (24 nm / BaO (5 nm / Fe (7 nm MTJs, which can be attributed to the preparation procedure and can be explained by the formation of Co- and Fe-oxides at the interfaces between the Heusler and the crystalline BaO barrier by comparing with theory. Although an amorphous structure of the BaO barrier seems to be confirmed by high-resolution transmission electron microscopy (TEM, it cannot entirely be ruled out that this is an artifact of TEM sample preparation due to the sensitivity of BaO to moisture. By replacing the BaO tunneling barrier with an MgO/BaO double layer barrier, the electric stability could effectively be increased by a factor of five. The resulting TMR effect is found to be about +20% at room temperature, although a fully antiparallel state has not been realized.

  3. A Dubious Distinction? The BA versus the BS in Psychology

    Science.gov (United States)

    Pfund, Rory A.; Norcross, John C.; Hailstorks, Robin; Aiken, Leona S.; Stamm, Karen E.; Christidis, Peggy

    2016-01-01

    Previous studies have documented small differences between the bachelor of arts (BA) and the bachelor of science (BS) psychology degrees in their general education core requirements, particularly mathematics and science courses. But are there differences between the BA and BS degrees within the psychology curriculum? Using data from the…

  4. Exotic decay in Ba isotopes via 12 C emission

    Indian Academy of Sciences (India)

    Considering Coulomb and proximity potentials as barriers, we have calculated the half lives for 12C emission from various Ba isotopes using different mass tables. The half life for 112Ba isotope calculated by us is 6.020 × 103 s which is comparable with the experimental value 5.620 × 103 s. From our study it is found that ...

  5. Ba II 4554 Å speckle imaging as solar Doppler diagnostic

    NARCIS (Netherlands)

    Sütterlin, P.; Rutten, R.J.; Skomorovsky, V.I.

    2001-01-01

    We present observations testing the Dopplergram capability of a narrow-band (80 mÅ) Lyot filter imaging the solar surface in the wings of the Ba II 4554 Å resonance line in combination with speckle reconstruction to obtain high angular resolution. The Ba II line is found to be an excellent tool

  6. Radioactive contamination of BaF2 crystal scintillator

    CERN Document Server

    Polischuk, O G; Bernabei, R; Cappella, F; Caracciolo, V; Cerulli, R; Di Marco, A; Danevich, F A; Incicchitti, A; Poda, D V; Tretyak, V I

    2013-01-01

    Barium fluoride (BaF$_2$) crystal scintillators are promising detectors to search for double beta decay processes in $^{130}$Ba ($Q_{2{\\beta}}$ = 2619(3) keV) and $^{132}$Ba ($Q_{2{\\beta}}$ = 844(1) keV). The $^{130}$Ba isotope is of particular interest because of the indications on 2${\\beta}$ decay found in two geochemical experiments. The radioactive contamination of BaF$_2$ scintillation crystal with mass of 1.714 kg was measured over 113.4 hours in a low-background DAMA/R&D set-up deep underground (3600 m w.e.) at the Gran Sasso National Laboratories of INFN (LNGS, Italy). The half-life of $^{212}$Po (present in the crystal scintillator due to contamination by radium) was estimated as $T_{1/2}$ = 298.8 $\\pm$ 0.8(stat.) $\\pm$ 1.4(syst.) ns by analysis of the events pulse profiles.

  7. Pengendalian Hayati Penyakit Layu Bakteri Tembakau: 1. Isolasi Bakteri Antagonis

    Directory of Open Access Journals (Sweden)

    Triwidodo Arwiyanto

    1997-09-01

    King s B while Bacillus spp. were isolated on Tryptic Soy Agar medium. Each media were supplemented with 100 ppm cycloheximide to suppress fungal growth. All isolated strains were tested for their capability to suppress the growth of Pseudomonas solanacearum on appropiate media. Most of fluorescent pseudomonad inhibited the growth of the pathogen with an inhibition zone from 1 mm to 16 mm. The mechanism of growth-inhibition was bacteriostatic and some of them were bactericidal. Sixty six out of 120 strains of Bacillus spp. produced defined inhibition zones on the media. The zone of growth-inhibition varied from 2 to 14 mm and the mechanism of inhibition was bactericidal. Several strains of those two bacterial marga exhibited non-antagonistic activity toward each other.

  8. Formulasi Bakteri Endofit Akar Kedelai untuk Pengendalian Pustul Bakteri

    Directory of Open Access Journals (Sweden)

    Trimurti Habazar

    2015-04-01

    Full Text Available Two isolates of bacterial endophyte from soybean root were found to be effective to control bacterial pustule caused by Xanthomonas axonopodis pv. glycines. Formulation of the bacterial isolates is required to maintain the effectivity of this bacterial isolates during storage, transportation and application. The aim of this research was to obtain the best carrier for formulation to maintain the effectivity of bacterial endophyte in storage to control bacterial pustule on soybean. Three kind of carrier agent was evaluated for formulation of bacterial endophyte i.e. peat soil, tapioca flour and coconut water + 1% palm oil. Each carrier agent was combined with 5 treatment of storage time i.e. 0, 1, 3, 5 and 7 weeks. Soybean plants was inoculated by. X. axonopodis pv. glycines 2 weeks after planting by rubbing bacterial suspension (106 cel mL-1 on lower surface of leaves. The results showed that all formulas of bacterial endophyte were able to suppress the bacterial pustule on soybean. The best formulations were bacterial endophyte in peat soil stored for 1 and 7 weeks (effectivity rate 79.85% and 77.02% and coconut water + palm oil and storaged for 3 weeks (effectivity rate 77.46%.

  9. Snakebites in Paraíba, Brazil

    Directory of Open Access Journals (Sweden)

    H. N. Albuquerque

    2005-09-01

    Full Text Available The epidemiological data on snakebites in the state of Paraíba, Brazil, is scarce. This accounts for the difficulties in helping the victims. Hence, to obtain the clinical and epidemic profile of the snakebite accidents in Paraíba, we studied the number of cases recorded in this state between January 1995 and December 2000. The data was collected from these sources: Center for Toxicological Assistance (Centro de Assistência Toxicológica - CEATOX and State Secretariat of Health (Secretaria Estadual de Saude, João Pessoa; 3rd Regional Health Center (3º Núcleo Regional de Saúde - NRS and the Division of Epidemiological Vigilance of the Municipal Secretariat of Health (Divisão de Vigilância Epidemiológica da Secretaria Municipal de Saúde - DVE/SMS, Campina Grande. The annual distribution of the snakebite incidence showed an irregularity and an increase in March, May and August; followed by a large reduction in November and December. It was also observed that snakebites occurred more frequently in the rural area, mainly among the male laborers between 10-49 years. In most cases, the bite occurred on the leg or foot. The interval between the snakebite and the medical assistance was less than six hours. The most common symptoms were pain, edema, erythema, and bleeding. The low lethality index and the high frequency of healing, without sequels, suggest that the treatment with serum neutralized the poison, indicating the efficacy of this treatment against snakebites by the specific species found in this region.

  10. When one becomes two: Ba12In4Se20, not quite isostructural to Ba12In4S19

    Science.gov (United States)

    Yin, Wenlong; Iyer, Abishek K.; Li, Chao; Yao, Jiyong; Mar, Arthur

    2017-09-01

    The ternary selenide Ba12In4Se20 was synthesized by reaction of BaSe, In2Se3, and Se at 1023 K. Single-crystal X-ray diffraction revealed a trigonal structure (space group R 3 bar, Z = 6, a = 10.0360(6) Å, c = 78.286(4) Å at room temperature) consisting of one-dimensional stacks of InSe4 tetrahedra, In2Se7 double tetrahedra, selenide Se2- anions, and diselenide Se22- anions, with Ba2+ cations in the intervening spaces. The selenide Ba12In4Se20 can be derived from the corresponding sulfide Ba12In4S19 by replacing one monoatomic Ch2- anion with a diatomic Ch22- anion. An optical band gap of 1.70(2) eV, consistent with the dark red colour of the crystals, was deduced from the UV-vis-NIR diffuse reflectance spectrum.

  11. KARAKTERISTIK FISIKOKIMIA TEPUNG BIJI SORGHUM (Sorghum bicolor L. TERFERMENTASI BAKTERI ASAM LAKTAT Lactobacilllus acidophilus-Physicochemical Characteristic of Fermented Sorghumflour (Sorghum bicolor L by Lactic Acid Bacteria Lactobacilllus acidophilus

    Directory of Open Access Journals (Sweden)

    Muhamad Kurniadi

    2013-11-01

    Full Text Available Sorghum flour utilization as food material has limited factors such as tannin content as the anti-nutrient. Various food fermentation using lactic acid bacteria was used to increase nutrient value and to reduce anti-nutrient. The objectives of this research were to improve nutrient characteristic of sorghum flour that was obtained by fermentation process optimization with variation of starter concentration and fermentation time. The research was designed using a factorial completely randomized design with period fermentation as first factor (0, 24, 36 and 48 hours and concentration of starter L. acidophilus (2, 4, and 6% v/b as second factor, 3 replicates for each treatments. Data were analyzed by using Analysis of Variance (ANOVA (P<0.05 and followed by Duncan multiple range tests as post hoc. The result showed that 48 hours fermentation period and 6% of L. acidophilus starter concentration as the best result for sorghum flour fermented. This sorghum fermented has physicochemical characteristic i.e. 1.365% of soluble protein, 1.278% of reducing sugars, 0.062% of tannin, 39.833 cP viscosity and 22.93 degree of whiteness. Keywords: Lactic acid bacteria, sorghum flour, physicochemical characteristics   ABSTRAK Pemanfaatan tepung sorghum sebagai bahan pangan memiliki keterbatasan salah satunya karena kandungan tanin sebagai anti-nutrisi. Beberapa proses fermentasi bahan pangan menggunakan bakteri asam laktat (BAL telah diketahui dapat meningkatkan kandungan nutrisi dan mengurangi kandungan anti-nutrisi. Tujuan penelitian ini adalah memperbaiki karakteristik nutrisi tepung sorghum melalui optimasi proses fermentasi dengan variasi konsentrasi starter BAL dan lama fermentasi. Penelitian dilakukan dengan menggunakan rancangan acak lengkap pola faktorial dengan lama fermentasi (0, 24, 36 dan 48 jam sebagai faktor pertama dan konsentrasi starter Lactobacillus acidophilus (2, 4 dan 6% v/b sebagai faktor kedua, menggunakan 3 ulangan. Parameter yang

  12. Ba-hexaferrite Films for Next Generation Microwave Devices (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Harris,V.; Chen, Z.; Chen, Y.; Yoon, S.; Sakai, T.; Geiler, A.; Yang, A.; He, Y.; Ziemer, K.; et al.

    2006-01-01

    Next generation magnetic microwave devices require ferrite films to be thick (>300 {mu}m), self-biased (high remanent magnetization), and low loss in the microwave and millimeter wave bands. Here we examine recent advances in the processing of thick Ba-hexaferrite (M-type) films using pulsed laser deposition (PLD), liquid-phase epitaxy, and screen printing. These techniques are compared and contrasted as to their suitability for microwave materials processing and industrial production. Recent advances include the PLD growth of BaM on wide-band-gap semiconductor substrates and the development of thick, self-biased, low-loss BaM films by screen printing.

  13. Leptonic B Decays at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Monorchio, Diego; /INFN, Naples /Naples U.

    2011-09-13

    The authors will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)} {nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be payed in order to perform a model independent analysis. A B-Factory provides an unique environment where to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  14. Leptonic B Decays at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Baracchini, Elisabetta; /Rome U. /INFN, Rome

    2011-11-10

    We will present the most recent results on leptonic B decays B{sup {+-}(0)} {yields} K*{sup {+-}(0)}{nu}{bar {nu}} and B{sup {+-}} {yields} {mu}{sup {+-}}{nu}, based on the data collected by the BaBar detector at PEP-II, an asymmetric e{sup +}e{sup -} collider at the center of mass energy of the {Upsilon}(4S) resonance. Rare B decays have always been a standard probe for New Physics (NP) searches. The very low Standard Model (SM) rate of these decays often make them unaccessible with the present experimental datasets, unless NP effects enhance the rate up to the current experimental sensitivity. Moreover, as NP effects can modify the decay kinematic, particular attention must be paid in order to perform a model independent analysis. A B-Factory provides an unique environment to investigate these processes. The high number of B{bar B} pairs produced by a B-Factory often allows to approach the needed experimental sensitivity. Moreover, the clean environment and the closed kinematic of the initial state enable to obtaining a very pure sample where to look for these decays.

  15. Isolation of Lactic Acid Bacteria That Produce Protease and Bacteriocin-Like Substance From Mud Crab (Scylla sp. Digestive Tract (Isolasi Bakteri Asam Laktat yang Menghasilkan Protease dan Senyawa Bacteriocin-Like dari Saluran Pencernaan Kepiting

    Directory of Open Access Journals (Sweden)

    Heru Pramono

    2015-03-01

    Kata kunci: Bakteri Asam Laktat, Bakteriosin-like substance, Protease, Scylla  sp. Digestive tract is complex environment consist of large amount of bacteria’s species. Fish intestine bacteria consist of aerobic or facultative anaerob bacteria which can produce antibacterial and enzym. The objectives of this research were to isolated lactic acid bacteria that produce bacteriocin-like and protease from mud crab digestive tract. Isolation and characterization of isolates were conducted employing media MRS.  Neutralized cell free supernatant of isolates were tested using disc diffusion agar of against pathogenic and spoilage bacteria to indicate bacteriocin-like-producing lactic acid bacteria. Protease-producing isolate was tested using disc diffusion method in casein agar. Among a hundred isolates, 96 isolates were showed clear zone in MRS+CaCO3,, catalase negative, and Gram positive bacteria. Thirty four isolates produced protease and only four isolates (i.e. IKP29, IKP30, IKP52, and IKP94 showed strong inhibition against pathogenic and spoilage bacteria. There were three patterns of inhibition among three isolates against Bacillus subtilis, Staphylococcus aureus, Eschericia coli, and Salmonella sp. All three isolates showed potential uses for produce starter culture for fishery product fermentation purpose. This is the first report of isolation lactic acid bacteria that produced protease and bacteriocin-like from digestive tract of mud crab. Keywords: Lactic acid bacteria, Bacteriocin-like substance, Protease, Scylla  sp.

  16. KITIN DARI LIMBAH CANGKANG UDANG SEBAGAI MEDIA UNTUK BAKTERI KITINOLITIK YANG DIISOLASI DARI LUMPUR SAWAH (Chitin from Waste of Shrimp Crab As Growth Medium for Chitinolytic Microorganism, Isolated from the Field Mud

    Directory of Open Access Journals (Sweden)

    Nuniek Herdyastuti

    2009-07-01

    Full Text Available ABSTRAK Limbah cangkang udang dimanfaatkan untuk memproduksi kitin sebagai media pertumbuahn bakteri kitinolitik. Enam isolat yang diperoleh dari lumpur sawah semuanya menunjukkan aktivitas kitinolitik. Hasil analisis selama 5 hari inkubasi menunjukkan bawah jumlah sel dan kadar protein diproduksi paling besar pada hari ke empat oleh isolat TNH23. Aktivitas kitinase tertinggi ditunjukkan oleh isolat TNH54 pada hari kedua sebesar 0,331 U/mL dan aktivitas spesifik 0,721 U/mg. isolat TNH23 dan TNH54 diduga mempunyai genus yang berbeda yaitu Aeoromonas hydrophyla dan Burcholderia pseudomallei.   ABSTRACT A shrimp crab waste have been using to produce chitin as growth medium chitinolytic microorganism. Six isolate has been  isolated from field mud showed that all have chitinolytic activity. The analysis result in 5 day incubation showed that the highest cell number and protein concentration is shown by TNH23 isolate. Chitinase activity is showed by TNH54  in second day 0.331 U/mL and specific activity 0.721U/mg.  TNH23 and TNH54 isolate are presumed to have different genus,  Aeromonas hydrophyla and Burcholderia pseudomallei

  17. Decay Data Evaluation Project (DDEP): Updated evaluation of the 133Ba, 140Ba, 140La and 141Ce decay characteristics

    Science.gov (United States)

    Chechev, Valerii P.; Kuzmenko, Nikolai K.

    2017-09-01

    Within the Decay Data Evaluation Project (DDEP) an updated comprehensive assessment has been made of the decay characteristics of 133Ba, 140Ba, 140La, and 141Ce. Experimental data published up to 2016 along with other information (new compilations, analyses and corrections) were taken into account. Newly evaluated values of the half-lives and a number of other key decay characteristics are presented in this paper for all four radionuclides.

  18. Syntheses, crystal structures, and optical properties of CsBa5Ti2Se9Cl and CsBa2Cl5

    Science.gov (United States)

    Mesbah, Adel; Prakash, Jai; Malliakas, Christos D.; Lebègue, Sébastien; Badawi, Michael; Ibers, James A.

    2017-09-01

    The mixed-cation compounds CsBa5Ti2Se9Cl and CsBa2Cl5 were synthesized in the same solid-state reaction at 1173 K. CsBa5Ti2Se9Cl adopts the Cs3CoCl5 structure type in the tetragonal crystal system whereas CsBa2Cl5 crystallizes in the PbU2Se5 structure type in the monoclinic crystal system. The CsBa5Ti2Se9Cl structure displays both Cs/Ba and Se/Cl disorder. From optical absorption measurements CsBa5Ti2Se9Cl is an indirect wide-gap semiconductor. From theoretical calculations CsBa2Cl5 has a large band gap of 6.4 eV.

  19. Metaplasia mieloide do baço na Ancilostomose

    Directory of Open Access Journals (Sweden)

    W. O. Cruz

    1934-06-01

    Full Text Available Pesquizamos, no figado e baço de dez casos puros de ancilostomose, elementos hemocitopoieticos; verificamos o peso do baço em 23 casos de individuos com idades compreendidas entre 3 e 60 anos; não encontramos, em nenhum caso, celulas hemoformadoras no figado. Em sete casos, encontramos, no baço, elementos da série vermelha em adiantado estado de evolução (eritroblastos ortocromaticos de nucleo picnotico. Em alguns destes casos observamos megacariocitos e numerosos mielocitos eosinofilos. Os tres casos que não apresentavam metaplasia mieloide no baço, eram os de individuos acima de 50 anos de idade. Entretanto, em outro caso de um individuo com 59 anos esta metaplasia foi verificada. Em individuos acima de 20 anos, o peso médio do baço, em nove casos, mostrou-se igual ao peso normal. Em 14 casos, compreendidos entre 3 e 14 anos, o peso deste orgão foi sempre sensivelmente mais elevado que nos normais de idade correspondente. Estes resultados sugerem a possibilidade de ser a metaplasia mieloide responsavel pelos aumentos de pezo nos baços de individuos jovens, vitimados pela anemia ancilostomica. A notavel proliferação dos eritroblastos ortocromaticos mostra que o grão e a rapidez da regeneração sanguinea, após a administração de ferro, são devidos, essencialmente, á grande quantidade de hemoglobina já preformada no baço e na medula ossea dos organismos ancilostomados.

  20. Thermoelectric properties of doped BaHfO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Dixit, Chandra Kr., E-mail: ckparadise@gmail.com, E-mail: sharmarameshfgiet@gmail.com [Dept. of Physics, Dr. Shakuntala Misra National Rehabilitation University, Lucknow-229001, U.P India (India); Bhamu, K. C. [Department of Physics, Goa University, Goa-403 206 (India); Sharma, Ramesh, E-mail: ckparadise@gmail.com, E-mail: sharmarameshfgiet@gmail.com [Dept. of Physics, Feroze Gandhi Institute of Engineering & Technology, Raebareli-229001, U.P India (India)

    2016-05-06

    We have studied the structural stability, electronic structure, optical properties and thermoelectric properties of doped BaHfO{sub 3} by full potential linearized augmented plane wave (FP-LAPW) method. The electronic structure of BaHfO{sub 3} doped with Sr shows enhances the indirect band gaps of 3.53 eV, 3.58 eV. The charge density plots show strong ionic bonding in Ba-Hf, and ionic and covalent bonding between Hf and O. Calculations of the optical spectra, viz., the dielectric function, refractive index and extinction coefficient are performed for the energy range are calculated and analyzed. Thermoelectric properties of semi conducting are also reported first time. The doped BaHfO{sub 3} is approximately wide band gap semiconductor with the large p-type Seebeck coefficient. The power factor of BaHfO{sub 3} is increased with Sr doping, decreases because of low electrical resistivity and thermal conductivity.

  1. Observation of the Nuclear Magnetic Octupole Moment of 137Ba+

    Science.gov (United States)

    Hoffman, Matthew

    Single trapped ions are ideal systems in which to test atomic physics at high precision, which can in turn be used for searches for violations of fundamental symmetries and physics beyond the standard model, in addition to quantum computation and a number of other applications. The ion is confined in ultra-high vacuum, is laser cooled to mK temperatures, and kept well isolated from the environment which allows these experimental efforts. In this thesis, a few diagnostic techniques will be discussed, covering a method to measure the linewidth of a narrowband laser in the presence of magnetic field noise, as well as a procedure to measure the ion's temperature using such a narrowband laser. This work has led to two precision experiments to measure atomic structure in 138Ba+, and 137Ba+ discussed here. First, employing laser and radio frequency spectroscopy techniques in 138Ba+, we measured the Lande- gJ factor of the 5D5/2 level at the part-per-million level, the highest precision to date. Later, the development of apparatus to efficiently trap and laser cool 137Ba+ has enabled a measurement of the hyperfine splittings of the 5D3/2 manifold, culminating in the observation of the nuclear magnetic octupole moment of 137Ba+.

  2. LaBaNiO{sub 4}: a Fermi glass

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, A; Dell' Amore, R; Mueller, K A [Physics Institute of the Universitaet of Zuerich, Winterthurerstrasse 190, CH-8057 Zuerich (Switzerland); Karpinski, J; Bukowski, Z [Laboratory for Solid-State Physics, ETH Zuerich HPF F-7, CH-8093 Zuerich (Switzerland); Medarde, M; Pomjakushina, E [Laboratory for Neutron Scattering, ETHZ and PSI, CH-5232 Villigen PSI (Switzerland)], E-mail: schilling@physik.uzh.ch

    2009-01-07

    Polycrystalline samples of LaSr{sub 1-x}Ba{sub x}NiO{sub 4} show a crossover from a state with metallic transport properties for x = 0 to an insulating state as x{yields}1. The end member LaBaNiO{sub 4} with a nominal nickel Ni 3d{sup 7} configuration might therefore be regarded as a candidate for an antiferromagnetic insulator. However, we do not observe any magnetic ordering in LaBaNiO{sub 4} down to 1.5 K, and despite its insulating transport properties several other physical properties of LaBaNiO{sub 4} resemble those of metallic LaSrNiO{sub 4}. Based on an analysis of electrical and thermal-conductivity data as well as magnetic-susceptibility and low-temperature specific-heat measurements, we suggest that LaBaNiO{sub 4} is a Fermi glass with a finite electron density of states at the Fermi level but these states are localized.

  3. Tikumu vienība Platona sokratiskajos dialogos

    OpenAIRE

    Skvireckis, Eduards

    2010-01-01

    Bakalaura darbā „Tikumu vienība Platona sokratiskajos dialogos” tiek skatīts viens no Sokrata paradoksiem – kā ir iespējams, ka individuālie tikumi (vīrišķība, taisnīgums, mērenība, dievbijība un saprātība) ir vienlaicīgi nošķirti viens no otra un katru tikumu veido viena un tā pati lieta – morālā zināšana. Šī problēma vistiešāk atklājas divos Platona dialogos, Protagorā un Lahētā, līdz ar to tie tika izmantoti kā pamats šajā darbā veiktajai analīzei. Darbā tika pierādīts, ka starp tiem ir ie...

  4. Synthesis of BaTiO3 nanoparticles from TiO2-coated BaCO3 particles derived using a wet-chemical method

    Directory of Open Access Journals (Sweden)

    Yuuki Mochizuki

    2014-03-01

    Full Text Available BaCO3 particles coated with amorphous TiO2 precursor are prepared by a wet chemical method to produce BaTiO3 nanoparticles at low temperatures. Subsequently, we investigate the formation behavior of BaTiO3 particles and the particle growth behavior when the precursor is subjected to heat treatment. The state of the amorphous TiO2 coating on the surface of BaCO3 particles depends on the concentration of NH4HCO3, and the optimum concentration is found to be in the range 0.5–1.0 M. Thermogravimetric curves of the BaCO3 particles coated with the TiO2 precursor, prepared from BaCO3 particles of various sizes, show BaTiO3 formation occurring mainly at 550–650 °C in the case of fine BaCO3 particles. However, as evidenced from the curves, the temperature of formation of BaTiO3 shifts to higher values with an increase in the size of the BaCO3 particles. The average particle size of single phase BaTiO3 at heat-treatment temperature of 650–900 °C is observed to be in the range 60–250 nm.

  5. Epitaxial growth of Fe/BaTiO3 heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Brivio, S., E-mail: m.gooley@elsevier.com [LNESS, Dipartimento di Fisica, Politecnico di Milano, via Anzani 42, 22100, Como (Italy); Rinaldi, C.; Petti, D.; Bertacco, R. [LNESS, Dipartimento di Fisica, Politecnico di Milano, via Anzani 42, 22100, Como (Italy); Sanchez, F. [Institut de Ciencia de Materials de Barcelona, Consejo Superior de Investigaciones Cientificas, Campus Universitat Autonoma de Barcelona, Bellaterra 08193, Catalunya (Spain)

    2011-06-30

    The realization of epitaxial heterostructures involving ferroelectric (FE) and ferromagnetic (FM) materials is one of the possible routes towards the realization of devices exploiting sizable magnetoelectric effects. In this paper we demonstrate the epitaxial growth of Fe on BaTiO{sub 3}(001) as this system represents a prototypical example of interface between well known FE and FM materials with bcc and perovskite structure respectively, both with Curie temperature well above 300 K. Fe grows on BaTiO{sub 3} with 45 deg. rotation of its cubic lattice with respect to that of the substrate in order to reduce the lattice mismatch. Negligible interdiffusion of Ba and Ti cations or Fe atoms is found by X-ray photoemission spectroscopy, while a sizable Fe oxidation occurs within an interfacial layer with thicknesses thinner than 3 nm.

  6. The BaBar instrumented flux return performance: lessons learned

    CERN Document Server

    Anulli, F; Baldini, R; Band, H R; Bionta, R; Brau, J E; Brigljevic, V; Buzzo, A; Calcaterra, A; Carpinelli, M; Cartaro, C; Cavallo, N; Crosetti, G; De Nardo, Gallieno; De Sangro, R; Eichenbaum, A; Fabozzi, F; Falciai, D; Ferrarotto, F; Ferroni, F; Finocchiaro, G; Forti, F; Frey, R; Gatto, C; Graug; Iakovlev, N I; Iwasaki, M; Johnson, J R; Lange, D J; Lista, L; Lo Vetere, M; Lü, C; Macri, M; Messner, R; Moore, T B; Morganti, S; Neal, H; Neri, N; Palano, A; Paoloni, E; Paolucci, P; Passaggio, S; Pastore, F C; Patteri, P; Peruzzi, I; Piccolo, D; Piccolo, M; Piredda, G; Robutti, E; Roodman, A; Santroni, A; Sciacca, C; Sinev, N B; Soha, A; Strom, D; Tosi, S; Vavra, J; Wisniewski, W J; Wright, D M; Xie, Y; Zallo, A

    2002-01-01

    The BaBar Collaboration has operated an instrumented flux return (IFR) system covering over 2000 m sup 2 with resistive plate chambers (RPCs) for nearly 3 years. The chambers are constructed of bakelite sheets separated by 2 mm. The inner surfaces are coated with linseed oil. This system provides muon and neutral hadron detection for BaBar. Installation and commissioning were completed in 1998, and operation began mid-year 1999. While initial performance of the system reached design, over time, a significant fraction of the RPCs demonstrated significant degradation, marked by increased currents and reduced efficiency. A coordinated effort of investigations have identified many of the elements responsible for the degradation. This article presents our current understanding of the aging process of the BaBar RPCs along with the action plan to combat performance degradation of the IFR system.

  7. Bi3+ Luminescence in ABiO2Cl (A = Sr, Ba) and BaBiO2Br

    Energy Technology Data Exchange (ETDEWEB)

    Porter-Chapman, Yetta D.; Bourret-Courchesne, Edith E.; Derenzo,Stephen E.

    2007-01-18

    Trivalent bismuth luminescence is reported in three Sillenbismuth oxyhalide phases, SrBiO2Cl, BaBiO2Cl, and BaBiO2Br. Thesecompounds exhibit Bi 6s6->6 s2 emission under UV and X-ray radiation.At room temperature, BaBiO2Cl shows the most intense light emission, withspectral and decay properties similar to those found in Bi4Ge3O12 (BGO).At low temperatures, each phase show an increase in the photoluminescenceintensities and a narrowing of the emission peaks. In contrast to thetemperature dependence of BGO, X-ray excited luminescence intensities ofall three phases remain relatively constant throughout the temperaturerange 10 - 295 K. This result indicates that the Sillen phases undergoless thermal quenching than BGO. The low temperature and room temperatureradio-luminescence decay times were determined from pulsed x-raymeasurements. At room temperature, SrBiO2Cl exhibits faster decays thanBGO, while, BaBiO2Cl and BaBiO2Br have decay times similar toBGO.

  8. EFEKTIVITAS KAPORIT PADA PROSES KLORINASI TERHADAP PENURUNAN BAKTERI Coliform DARI LIMBAH CAIR RUMAH SAKIT X SAMARINDA (The Effectiveness of Calcium Hypochlorite to Chlorination Process in Decreasing the Amount of Coliform Bacteria in the Wastewater of X

    Directory of Open Access Journals (Sweden)

    Muhammad Busyairi

    2016-07-01

    Full Text Available ABSTRAK Kaporit pada limbah cair rumah sakit digunakan sebagai desinfektan, tetapi, penggunaan kaporit dengan dosis yang tidak tepat akan menyebabkan pembentukan senyawa Trihalomethane (THMs yang beracun dan bersifat karsinogenik. Pada limbah cair rumah sakit X Samarinda, diperoleh nilai MPN Coliform sebesar >160.000 MPN / 100 mL dengan residu klor sebesar 0 ppm. Penelitian ini bertujuan untuk menentukan dosis optimum dari penggunaan kaporit menggunakan titik Breakpoint Chlorination (BPC dan pengaruhnya terhadap penurunan Coliform. Analisis dilakukan dengan titrasi iodometri dan menghitung jumlah bakteri Coliform memakai metode Most Probable Number (MPN. Penentuan dosis kaporit berdasarkan dosis optimum pada titik BPC dimaksudkan agar dapat menjaga residu klor dari penambahan dosis yang semakin meningkat. Hasil penelitian mempengarui rerata kadar bahan organik pada sampel limbah cair sebesar 137,26 ppm, sehingga dosis kaporit yang dibubuhkan dimulai dari 130-165 ppm. Titik BPC terjadi pada pembubuhan klor aktif 160 ppm untuk kedua waktu kontak yaitu 30 dan 40 menit. Pada titik BPC, waktu kontak 30 menit diperoleh rerata persentase penurunan nilai Coliform yaitu 98,21% sebesar 2.899 MPN / 100 mL dengan residu klor sebesar 88 ppm. Pada waktu kontak 40 menit diperoleh persentase penurunan bakteri Coliform hingga 98,83%, yaitu dari >160.000/100 mL menjadi 1.866/100 mL dengan residu klor 97,5 ppm. ABSTRACT Calcium hypochlorite of hospital wastewater serves as disinfectant, however, inappropriate dose of it will lead to the formation of Trihalomethane (THMs which is toxic and carcinogenic. The value of MPN Coliform of wastewater in X hospital Samarinda is >160.000 MPN / 100 mL with residual chlorine 0 ppm. This research aims at determining the optimum dose of calcium hypochlorite usage by using Breakpoint Chlorination curve and its effect to Coliform decrease. Further, the analysis is done by employing iodometric titration and the amount of Coliform

  9. The Danish Microbiology Database (MiBa) 2010 to 2013

    DEFF Research Database (Denmark)

    Voldstedlund, M; Haarh, M; Mølbak, Kaare

    2014-01-01

    The Danish Microbiology Database (MiBa) is a national database that receives copies of reports from all Danish departments of clinical microbiology. The database was launched in order to provide healthcare personnel with nationwide access to microbiology reports and to enable real-time surveillance...... of communicable diseases and microorganisms. The establishment and management of MiBa has been a collaborative process among stakeholders, and the present paper summarises lessons learned from this nationwide endeavour which may be relevant to similar projects in the rapidly changing landscape of health...

  10. Isovector states in /sup 128-134/Ba

    Energy Technology Data Exchange (ETDEWEB)

    Harter, H.; Lipas, P.O.; Nojarov, R.; Taigel, T.; Faessler, A.

    1988-04-28

    Phenomenological IBA-2 and microscopic QRPA are applied to predict isovector, or mixed-symmetry, states in /sup 128-134/Ba. The lowest 1/sup +/ state is found at 2.6-3.2 MeV with B(M1)arrow up approx. = 0.1-0.4 ..mu../sub N//sup 2/. IBA predictions are also given for the lowest mixed 2/sup +/ state at 2.2-2.7 MeV. A very strong (up to 5 ..mu../sub N//sup 2/) 1/sup +/ doublet is predicted (QRPA) at 4.7 MeV in /sup 130-134/Ba.

  11. The Danish Microbiology Database (MiBa) 2010 to 2013.

    Science.gov (United States)

    Voldstedlund, M; Haarh, M; Mølbak, K

    2014-01-09

    The Danish Microbiology Database (MiBa) is a national database that receives copies of reports from all Danish departments of clinical microbiology. The database was launched in order to provide healthcare personnel with nationwide access to microbiology reports and to enable real-time surveillance of communicable diseases and microorganisms. The establishment and management of MiBa has been a collaborative process among stakeholders, and the present paper summarises lessons learned from this nationwide endeavour which may be relevant to similar projects in the rapidly changing landscape of health informatics.

  12. Development of BaSO sub 4 :Eu thermoluminescence phosphor

    CERN Document Server

    Madhusoodanan, U; Lakshmanan, A R

    1999-01-01

    A highly sensitive thermoluminescence (TL) phosphor based on BaSO sub 4 :Eu was developed following the coprecipitation technique and firing in argon atmosphere at 1123 K. Photoluminescence studies confirm that firing in argon atmosphere instead of air increased the incorporation of Eu ions in 2+ valence state. At low gamma-ray doses, its TL sensitivity is nearly 2 to 3 times higher than that of CaSO sub 4 :Dy phosphor. The other salient features of this BaSO sub 4 :Eu TL phosphor are a constant glow curve shape and a nearly linear gamma-ray dose response.

  13. Results on conventional and exotic charmonium at BaBar

    CERN Document Server

    Bernard, Denis

    2013-01-01

    The B factories provide a unique playground for studying the properties of conventional and exotic charmonium states. We present recent results in initial state radiation and two-photon fusion, obtained using the full data set collected by the BaBar experiment. Amongst BaBar 's harvest presented in this talk, the determination of the quantum numbers of the X(3915) resonance, a body of concording evidence pointing to JPC = 1++ for the X(3872), and updates on the family of the Y resonance to the full integrated luminosity.

  14. Punta Pitt, Galapagos Ba/Ca Data for 1963-1982

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — File contains Ba/Ca data (in mmol/mol) presented by Lea et al. (1989). Samples were measured at the Massachusetts Institute of Technology by D. Lea. Ba...

  15. Growth and characterization of acentric BaHf(BO{sub 3}){sub 2} and BaZr(BO{sub 3}){sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Mączka, Mirosław, E-mail: m.maczka@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wrocław 2 (Poland); Szymborska-Małek, Katarzyna; Gągor, Anna [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, P.O. Box 1410, 50-950 Wrocław 2 (Poland); Majchrowski, Andrzej [Institute of Applied Physics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warszawa (Poland)

    2015-05-15

    Growth, single crystal X-ray diffraction, polarized Raman and infrared (IR) studies of BaHf(BO{sub 3}){sub 2} are presented. Raman and IR spectra of polycrystalline BaZr(BO{sub 3}){sub 2} are also reported to facilitate assignment of modes. BaHf(BO{sub 3}){sub 2} borate crystallizes in trigonal system, space group R3c, with lattice parameters: a=5.1540(4) Å, c=33.901(3) Å. It accommodates dolomite-like structure doubled in the c direction, which is built of alternating layers of HfO{sub 6} octahedra and BaO{sub 6} distorted trigonal prisms that are connected through borate groups. The obtained structural as well as spectroscopic data show that BaHf(BO{sub 3}){sub 2} is isostructural with BaZr(BO{sub 3}){sub 2} and the deviations from centrosymmetry is small. - Graphical abstract: Arrangement of BO{sub 3} groups in BaHf(BO{sub 3}){sub 2} along the c direction in one unit cell. Dark and light blue denote different borate groups. - Highlights: • BaHf(BO{sub 3}){sub 2} single crystals were grown. • X-ray diffraction showed that this borate crystallizes in the acentric R3c structure. • Raman and IR spectra were measured for BaHf(BO{sub 3}){sub 2} and BaZr(BO{sub 3}){sub 2}, respectively. • Assignment of modes is proposed.

  16. Barium stable isotopes in the global ocean: Tracer of Ba inputs and utilization

    Science.gov (United States)

    Hsieh, Yu-Te; Henderson, Gideon M.

    2017-09-01

    Barium has been used as a biogeochemical tracer for alkalinity, productivity, and riverine inputs in the ocean, but its oceanic cycle remains poorly constrained. Barium stable isotope measurements may improve the use of Ba as a tracer and better constrain the cycling of Ba, but data are only available in limited regions of the oceans. In this study, we present dissolved seawater Ba isotopic compositions in a sample collection spanning the North Atlantic, South Atlantic, North Pacific and Southern Oceans. Compiled global upper-ocean [Ba] data show a relatively constant [Ba] (35-45 nM) in the near-surface waters throughout the global ocean, with the exception of areas near river inputs or strong upwelling. The relatively uniform distribution of [Ba] in the upper ocean seawater indicates that Ba removal is slow relative to supply and mixing, and implies that near-surface Ba isotope values are controlled by basin-scale balances rather than by regional or short-term processes. Seawater Ba isotopic compositions show a large variation of δ 138 / 134 Ba values ranging from 0.24 to 0.65‰, and a tight relationship with [Ba]. This global relationship can be simply modelled assuming a primary deep Southern Ocean source for Ba to yield a maximum isotope fractionation of α = 1.00058 ± 0.00010 (α =seawater 138/134Ba/particle 138/134Ba). This suggested isotope fractionation during Ba removal from seawater is larger than implied by laboratory measurement during barite formation, suggesting additional fractionating phases or a two-stage fractionation process. Riverine input from the Rio de la Plata to the South Atlantic has a signature of δ 138 / 134 Ba = - 0.06- 0.11 ‰, which is too light to explain the heavy values (>0.58‰) observed in the surface open ocean. Globally, the Ba isotope composition of the upper ocean waters is correlated with the fraction of Ba utilization at the basin scale (which varies from <15 to 70% at sites studied here). In the deep Atlantic Ocean

  17. De BaSO-fiche: een artefact in actie

    NARCIS (Netherlands)

    März, V.; Vermeir, K.; Kelchtermans, G.

    2014-01-01

    Via onderwijsvernieuwingen wil men de praktijk van onderwijzen en leren verbeteren. Die vernieuwingen worden ook ondersteund door artefacten zoals een nieuw schoolboek, een stappenplan of een fiche. Aan de hand van de implementatie van de BaSO-fiche in twee basis- en twee secundaire scholen wordt

  18. The BaBar detector: Upgrades, operation and performance

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; del Amo Sanchez, P.; Gaillard, J. -M.; Hicheur, A.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prudent, X.; Robbe, P.; Tisserand, V.; Zghiche, A.; Grauges, E.; Garra Tico, J.; Lopez, L.; Martinelli, M.; Palano, A.; Pappagallo, M.; Pompili, A.; Chen, G. P.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Stugu, B.; Sun, L.; Abrams, G. S.; Battaglia, M.; Borgland, A. W.; Breon, A. B.; Brown, D. N.; Button-Shafer, J.; Cahn, R. N.; Charles, E.; Clark, A. R.; Day, C. T.; Furman, M.; Gill, M. S.; Groysman, Y.; Jacobsen, R. G.; Kadel, R. W.; Kadyk, J. A.; Kerth, L. T.; Kolomensky, Yu. G.; Kral, J. F.; Kukartsev, G.; LeClerc, C.; Levi, M. E.; Lynch, G.; Merchant, A. M.; Mir, L. M.; Oddone, P. J.; Orimoto, T. J.; Osipenkov, I. L.; Pripstein, M.; Roe, N. A.; Romosan, A.; Ronan, M. T.; Shelkov, V. G.; Suzuki, A.; Tackmann, K.; Tanabe, T.; Wenzel, W. A.; Zisman, M.; Barrett, M.; Bright-Thomas, P. G.; Ford, K. E.; Harrison, T. J.; Hart, A. J.; Hawkes, C. M.; Knowles, D. J.; Morgan, S. E.; O' Neale, S. W.; Penny, R. C.; Smith, D.; Soni, N.; Watson, A. T.; Watson, N. K.; Goetzen, K.; Held, T.; Koch, H.; Kunze, M.; Lewandowski, B.; Pelizaeus, M.; Peters, K.; Schmuecker, H.; Schroeder, T.; Steinke, M.; Fella, A.; Antonioli, E.; Boyd, J. T.; Chevalier, N.; Cottingham, W. N.; Foster, B.; Mackay, C.; Walker, D.; Abe, K.; Asgeirsson, D. J.; Cuhadar-Donszelmann, T.; Fulsom, B. G.; Hearty, C.; Knecht, N. S.; Mattison, T. S.; McKenna, J. A.; Thiessen, D.; Khan, A.; Kyberd, P.; McKemey, A. K.; Randle-Conde, A.; Saleem, M.; Sherwood, D. J.; Teodorescu, L.; Blinov, V. E.; Bukin, A. D.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Korol, A. A.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Telnov, V. I.; Todyshev, K. Yu.; Yushkov, A. N.; Best, D. S.; Bondioli, M.; Bruinsma, M.; Chao, M.; Curry, S.; Eschrich, I.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Martin, E. C.; McMahon, S.; Mommsen, R. K.; Stoker, D. P.; Abachi, S.; Buchanan, C.; Hartfiel, B. L.; Weinstein, A. J. R.; Atmacan, H.; Foulkes, S. D.; Gary, J. W.; Layter, J.; Liu, F.; Long, O.; Shen, B. C.; Vitug, G. M.; Wang, K.; Yasin, Z.; Zhang, L.; Hadavand, H. K.; Hill, E. J.; Paar, H. P.; Rahatlou, S.; Schwanke, U.; Sharma, V.; Berryhill, J. W.; Campagnari, C.; Cunha, A.; Dahmes, B.; Hong, T. M.; Kovalskyi, D.; Kuznetsova, N.; Levy, S. L.; Lu, A.; Mazur, M. A.; Richman, J. D.; Verkerke, W.; Beck, T. W.; Beringer, J.; Eisner, A. M.; Flacco, C. J.; Grillo, A. A.; Grothe, M.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Nesom, G.; Schalk, T.; Schmitz, R. E.; Schumm, B. A.; Seiden, A.; Spencer, E.; Spradlin, P.; Turri, M.; Walkowiak, W.; Wang, L.; Wilder, M.; Williams, D. C.; Wilson, M. G.; Winstrom, L. O.; Chen, E.; Cheng, C. H.; Doll, D. A.; Dorsten, M. P.; Dvoretskii, A.; Echenard, B.; Erwin, R. J.; Fang, F.; Flood, K.; Hitlin, D. G.; Metzler, S.; Narsky, I.; Oyang, J.; Piatenko, T.; Porter, F. C.; Ryd, A.; Samuel, A.; Yang, S.; Zhu, R. Y.; Andreassen, R.; Devmal, S.; Geld, T. L.; Jayatilleke, S.; Mancinelli, G.; Meadows, B. T.; Mishra, K.; Sokoloff, M. D.; Abe, T.; Antillon, E. A.; Barillari, T.; Becker, J.; Blanc, F.; Bloom, P. C.; Chen, S.; Clifton, Z. C.; Derrington, I. M.; Destree, J.; Dima, M. O.; Ford, W. T.; Gaz, A.; Gilman, J. D.; Hachtel, J.; Hirschauer, J. F.; Johnson, D. R.; Kreisel, A.; Nagel, M.; Nauenberg, U.; Olivas, A.; Rankin, P.; Roy, J.; Ruddick, W. O.; Smith, J. G.; Ulmer, K. A.; van Hoek, W. C.; Wagner, S. R.; West, C. G.; Zhang, J.; Ayad, R.; Blouw, J.; Chen, A.; Eckhart, E. A.; Harton, J. L.; Hu, T.; Toki, W. H.; Wilson, R. J.; Winklmeier, F.; Zeng, Q. L.; Altenburg, D.; Feltresi, E.; Hauke, A.; Jasper, H.; Karbach, M.; Merkel, J.; Petzold, A.; Spaan, B.; Wacker, K.; Brandt, T.; Brose, J.; Colberg, T.; Dahlinger, G.; Dickopp, M.; Eckstein, P.; Futterschneider, H.; Kaiser, S.; Kobel, M. J.; Krause, R.; Müller-Pfefferkorn, R.; Mader, W. F.; Maly, E.; Nogowski, R.; Otto, S.; Schubert, J.; Schubert, K. R.; Schwierz, R.; Sundermann, J. E.; Volk, A.; Wilden, L.; Bernard, D.; Brochard, F.; Cohen-Tanugi, J.; Dohou, F.; Ferrag, S.; Latour, E.; Mathieu, A.; Renard, C.; Schrenk, S.; T' Jampens, S.; Thiebaux, Ch.; Vasileiadis, G.; Verderi, M.; Anjomshoaa, A.; Bernet, R.; Clark, P. J.; Lavin, D. R.; Muheim, F.; Playfer, S.; Robertson, A. I.; Swain, J. E.; Watson, J. E.; Xie, Y.; Andreotti, D.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Carassiti, V.; Cecchi, A.; Cibinetto, G.; Cotta Ramusino, A.; Evangelisti, F.; Fioravanti, E.; Franchini, P.; Garzia, I.; Landi, L.; Luppi, E.; Malaguti, R.; Negrini, M.; Padoan, C.; Petrella, A.; Piemontese, L.; Santoro, V.; Sarti, A.; Anulli, F.; Baldini-Ferroli, R.; Calcaterra, A.; Finocchiaro, G.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; de Sangro, R.; Santoni, M.; Zallo, A.; Bagnasco, S.; Buzzo, A.; Capra, R.; Contri, R.; Crosetti, G.; Lo Vetere, M.; Macri, M. M.; Minutoli, S.; Monge, M. R.; Musico, P.; Passaggio, S.; Pastore, F. C.; Patrignani, C.; Pia, M. G.; Robutti, E.; Santroni, A.; Tosi, S.; Bhuyan, B.; Prasad, V.; Bailey, S.; Brandenburg, G.; Chaisanguanthum, K. S.; Lee, C. L.; Morii, M.; Won, E.; Wu, J.; Adametz, A.; Dubitzky, R. S.; Marks, J.; Schenk, S.; Uwer, U.; Klose, V.; Lacker, H. M.; Aspinwall, M. L.; Bhimji, W.; Bowerman, D. A.; Dauncey, P. D.; Egede, U.; Flack, R. L.; Gaillard, J. R.; Gunawardane, N. J. W.; Morton, G. W.; Nash, J. A.; Nikolich, M. B.; Panduro Vazquez, W.; Sanders, P.; Smith, D.; Taylor, G. P.; Tibbetts, M.; Behera, P. K.; Chai, X.; Charles, M. J.; Grenier, G. J.; Hamilton, R.; Lee, S. -J.; Mallik, U.; Meyer, N. T.; Chen, C.; Cochran, J.; Crawley, H. B.; Dong, L.; Eyges, V.; Fischer, P. -A.; Lamsa, J.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gao, Y. Y.; Gritsan, A. V.; Guo, Z. J.; Lae, C. K.; Schott, G.; Albert, J. N.; Arnaud, N.; Beigbeder, C.; Breton, D.; Davier, M.; Derkach, D.; Dû, S.; Firmino da Costa, J.; Grosdidier, G.; Höcker, A.; Laplace, S.; Le Diberder, F.; Lepeltier, V.; Lutz, A. M.; Malaescu, B.; Nief, J. Y.; Petersen, T. C.; Plaszczynski, S.; Pruvot, S.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Tocut, V.; Trincaz-Duvoid, S.; Wang, L. L.; Wormser, G.; Bionta, R. M.; Brigljević, V.; Lange, D. J.; Simani, M. C.; Wright, D. M.; Bingham, I.; Burke, J. P.; Chavez, C. A.; Coleman, J. P.; Forster, I. J.; Fry, J. R.; Gabathuler, E.; Gamet, R.; George, M.; Hutchcroft, D. E.; Kay, M.; Parry, R. J.; Payne, D. J.; Schofield, K. C.; Sloane, R. J.; Touramanis, C.; Azzopardi, D. E.; Bellodi, G.; Bevan, A. J.; Clarke, C. K.; Cormack, C. M.; Di Lodovico, F.; Dixon, P.; George, K. A.; Menges, W.; Potter, R. J. L.; Sacco, R.; Shorthouse, H. W.; Sigamani, M.; Strother, P.; Vidal, P. B.; Brown, C. L.; Cowan, G.; Flaecher, H. U.; George, S.; Green, M. G.; Hopkins, D. A.; Jackson, P. S.; Kurup, A.; Marker, C. E.; McGrath, P.; McMahon, T. R.; Paramesvaran, S.; Salvatore, F.; Vaitsas, G.; Winter, M. A.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Prencipe, E.; Allison, J.; Alwyn, K. E.; Bailey, D. S.; Barlow, N. R.; Barlow, R. J.; Chia, Y. M.; Edgar, C. L.; Forti, A. C.; Fullwood, J.; Hart, P. A.; Hodgkinson, M. C.; Jackson, F.; Jackson, G.; Kelly, M. P.; Kolya, S. D.; Lafferty, G. D.; Lyon, A. J.; Naisbit, M. T.; Savvas, N.; Weatherall, J. H.; West, T. J.; Williams, J. C.; Yi, J. I.; Anderson, J.; Farbin, A.; Hulsbergen, W. D.; Jawahery, A.; Lillard, V.; Roberts, D. A.; Schieck, J. R.; Simi, G.; Tuggle, J. M.; Blaylock, G.; Dallapiccola, C.; Hertzbach, S. S.; Kofler, R.; Koptchev, V. B.; Li, X.; Moore, T. B.; Salvati, E.; Saremi, S.; Staengle, H.; Willocq, S. Y.; Cowan, R.; Dujmic, D.; Fisher, P. H.; Henderson, S. W.; Koeneke, K.; Lang, M. I.; Sciolla, G.; Spitznagel, M.; Taylor, F.; Yamamoto, R. K.; Yi, M.; Zhao, M.; Zheng, Y.; Klemetti, M.; Lindemann, D.; Mangeol, D. J. J.; Mclachlin, S. E.; Milek, M.; Patel, P. M.; Robertson, S. H.; Biassoni, P.; Cerizza, G.; Lazzaro, A.; Lombardo, V.; Neri, N.; Palombo, F.; Pellegrini, R.; Stracka, S.; Bauer, J. M.; Cremaldi, L.; Eschenburg, V.; Kroeger, R.; Reidy, J.; Sanders, D. A.; Summers, D. J.; Zhao, H. W.; Godang, R.; Brunet, S.; Cote, D.; Nguyen, X.; Simard, M.; Taras, P.; Viaud, B.; Nicholson, H.; Cavallo, N.; De Nardo, G.; Fabozzi, F.; Gatto, C.; Lista, L.; Monorchio, D.; Onorato, G.; Paolucci, P.; Piccolo, D.; Sciacca, C.; Baak, M. A.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; LoSecco, J. M.; Wang, W. F.; Allmendinger, T.; Benelli, G.; Brau, B.; Corwin, L. A.; Gan, K. K.; Honscheid, K.; Hufnagel, D.; Kagan, H.; Kass, R.; Morris, J. P.; Rahimi, A. M.; Regensburger, J. J.; Smith, D. S.; Ter-Antonyan, R.; Wong, Q. K.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Iwasaki, M.; Kolb, J. A.; Lu, M.; Potter, C. T.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Borsato, E.; Castelli, G.; Colecchia, F.; Crescente, A.; Dal Corso, F.; Dorigo, A.; Fanin, C.; Furano, F.; Gagliardi, N.; Galeazzi, F.; Margoni, M.; Marzolla, M.; Michelon, G.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Solagna, P.; Stevanato, E.; Stroili, R.; Tiozzo, G.; Voci, C.; Akar, S.; Bailly, P.; Ben-Haim, E.; Bonneaud, G.; Briand, H.; Chauveau, J.; Hamon, O.; John, M. J. J.; Lebbolo, H.; Leruste, Ph.; Malclès, J.; Marchiori, G.; Martin, L.; Ocariz, J.; Perez, A.; Pivk, M.; Prendki, J.; Roos, L.; Sitt, S.; Stark, J.; Thérin, G.; Vallereau, A.; Biasini, M.; Covarelli, R.; Manoni, E.; Pennazzi, S.; Pioppi, M.; Angelini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Bucci, F.; Calderini, G.; Carpinelli, M.; Cenci, R.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Marchiori, G.; Morganti, M.; Morsani, F.; Paoloni, E.; Raffaelli, F.; Rizzo, G.; Sandrelli, F.; Triggiani, G.; Walsh, J. J.; Haire, M.; Judd, D.; Biesiada, J.; Danielson, N.; Elmer, P.; Fernholz, R. E.; Lau, Y. P.; Lu, C.; Miftakov, V.; Olsen, J.; Lopes Pegna, D.; Sands, W. R.; Smith, A. J. S.; Telnov, A. V.; Tumanov, A.; Varnes, E. W.; Baracchini, E.; Bellini, F.; Bulfon, C.; Buccheri, E.; Cavoto, G.; D' Orazio, A.; Di Marco, E.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Jackson, P. D.; Lamanna, E.; Leonardi, E.; Li Gioi, L.; Lunadei, R.; Mazzoni, M. A.; Morganti, S.; Piredda, G.; Polci, F.; del Re, D.; Renga, F.; Safai Tehrani, F.; Serra, M.; Voena, C.; Bünger, C.; Christ, S.; Hartmann, T.; Leddig, T.; Schröder, H.; Wagner, G.; Waldi, R.; Adye, T.; Bly, M.; Brew, C.; Condurache, C.; De Groot, N.; Franek, B.; Geddes, N. I.; Gopal, G. P.; Olaiya, E. O.; Ricciardi, S.; Roethel, W.; Wilson, F. F.; Xella, S. M.; Aleksan, R.; Bourgeois, P.; Emery, S.; Escalier, M.; Esteve, L.; Gaidot, A.; Ganzhur, S. F.; Giraud, P. -F.; Georgette, Z.; Graziani, G.; Hamel de Monchenault, G.; Kozanecki, W.; Langer, M.; Legendre, M.; London, G. W.; Mayer, B.; Micout, P.; Serfass, B.; Vasseur, G.; Yèche, Ch.; Zito, M.; Allen, M. T.; Akre, R.; Aston, D.; Azemoon, T.; Bard, D. J.; Bartelt, J.; Bartoldus, R.; Bechtle, P.; Becla, J.; Benitez, J. F.; Berger, N.; Bertsche, K.; Boeheim, C. T.; Bouldin, K.; Boyarski, A. M.; Boyce, R. F.; Browne, M.; Buchmueller, O. L.; Burgess, W.; Cai, Y.; Cartaro, C.; Ceseracciu, A.; Claus, R.; Convery, M. R.; Coupal, D. P.; Craddock, W. W.; Crane, G.; Cristinziani, M.; DeBarger, S.; Decker, F. J.; Dingfelder, J. C.; Donald, M.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Ecklund, S.; Erickson, R.; Fan, S.; Field, R. C.; Fisher, A.; Fox, J.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Gaponenko, I.; Glanzman, T.; Gowdy, S. J.; Graham, M. T.; Grenier, P.; Hadig, T.; Halyo, V.; Haller, G.; Hamilton, J.; Hanushevsky, A.; Hasan, A.; Hast, C.; Hee, C.; Himel, T.; Hryn' ova, T.; Huffer, M. E.; Hung, T.; Innes, W. R.; Iverson, R.; Kaminski, J.; Kelsey, M. H.; Kim, H.; Kim, P.; Kharakh, D.; Kocian, M. L.; Krasnykh, A.; Krebs, J.; Kroeger, W.; Kulikov, A.; Kurita, N.; Langenegger, U.; Leith, D. W. G. S.; Lewis, P.; Li, S.; Libby, J.; Lindquist, B.; Luitz, S.; Lüth, V.; Lynch, H. L.; MacFarlane, D. B.; Marsiske, H.; McCulloch, M.; McDonald, J.; Melen, R.; Menke, S.; Metcalfe, S.; Messner, R.; Moss, L. J.; Mount, R.; Muller, D. R.; Neal, H.; Nelson, D.; Nelson, S.; Nordby, M.; Nosochkov, Y.; Novokhatski, A.; O' Grady, C. P.; O' Neill, F. G.; Ofte, I.; Ozcan, V. E.; Perazzo, A.; Perl, M.; Petrak, S.; Piemontese, M.; Pierson, S.; Pulliam, T.; Ratcliff, B. N.; Ratkovsky, S.; Reif, R.; Rivetta, C.; Rodriguez, R.; Roodman, A.; Salnikov, A. A.; Schietinger, T.; Schindler, R. H.; Schwarz, H.; Schwiening, J.; Seeman, J.; Smith, D.; Snyder, A.; Soha, A.; Stanek, M.; Stelzer, J.; Su, D.; Sullivan, M. K.; Suzuki, K.; Swain, S. K.; Tanaka, H. A.; Teytelman, D.; Thompson, J. M.; Tinslay, J. S.; Trunov, A.; Turner, J.; van Bakel, N.; van Winkle, D.; Va' vra, J.; Wagner, A. P.; Weaver, M.; Weinstein, A. J. R.; Weber, T.; West, C. A.; Wienands, U.; Wisniewski, W. J.; Wittgen, M.; Wittmer, W.; Wright, D. H.; Wulsin, H. W.; Yan, Y.; Yarritu, A. K.; Yi, K.; Yocky, G.; Young, C. C.; Ziegler, V.; Chen, X. R.; Liu, H.; Park, W.; Purohit, M. V.; Singh, H.; Weidemann, A. W.; White, R. M.; Wilson, J. R.; Yumiceva, F. X.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Edwards, A. J.; Majewski, S. A.; Meyer, T. I.; Miyashita, T. S.; Petersen, B. A.; Roat, C.; Ahmed, M.; Ahmed, S.; Alam, M. S.; Bula, R.; Ernst, J. A.; Jain, V.; Liu, J.; Pan, B.; Saeed, M. A.; Wappler, F. R.; Zain, S. B.; Gorodeisky, R.; Guttman, N.; Peimer, D.; Soffer, A.; De Silva, A.; Lund, P.; Krishnamurthy, M.; Ragghianti, G.; Spanier, S. M.; Wogsland, B. J.; Eckmann, R.; Ritchie, J. L.; Ruland, A. M.; Satpathy, A.; Schilling, C. J.; Schwitters, R. F.; Wray, B. C.; Drummond, B. W.; Izen, J. M.; Kitayama, I.; Lou, X. C.; Ye, S.; Bianchi, F.; Bona, M.; Gallo, F.; Gamba, D.; Pelliccioni, M.; Bomben, M.; Borean, C.; Bosisio, L.; Cossutti, F.; Della Ricca, G.; Dittongo, S.; Grancagnolo, S.; Lanceri, L.; Poropat, P.; Rashevskaya, I.; Vitale, L.; Vuagnin, G.; Manfredi, P. F.; Re, V.; Speziali, V.; Frank, E. D.; Gladney, L.; Guo, Q. H.; Panetta, J.; Azzolini, V.; Lopez-March, N.; Martinez-Vidal, F.; Milanes, D. A.; Oyanguren, A.; Agarwal, A.; Albert, J.; Banerjee, Sw.; Bernlochner, F. U.; Brown, C. M.; Choi, H. H. F.; Fortin, D.; Fransham, K. B.; Hamano, K.; Kowalewski, R.; Lewczuk, M. J.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Back, J. J.; Gershon, T. J.; Harrison, P. F.; Ilic, J.; Latham, T. E.; Mohanty, G. B.; Puccio, E.; Band, H. R.; Chen, X.; Cheng, B.; Dasu, S.; Datta, M.; Eichenbaum, A. M.; Hollar, J. J.; Hu, H.; Johnson, J. R.; Kutter, P. E.; Li, H.; Liu, R.; Mellado, B.; Mihalyi, A.; Mohapatra, A. K.; Pan, Y.; Pierini, M.; Prepost, R.; Scott, I. J.; Tan, P.; Vuosalo, C. O.; von Wimmersperg-Toeller, J. H.; Wu, S. L.; Yu, Z.; Greene, M. G.; Kordich, T. M. B.

    2013-11-01

    The BaBar detector operated successfully at the PEP-II asymmetric e+e- collider at the SLAC National Accelerator Laboratory from 1999 to 2008. This report covers upgrades, operation, and performance of the collider and the detector systems, as well as the trigger, online and offline computing, and aspects of event reconstruction since the beginning of data taking.

  19. Enhanced Optical Performance of BaMgAl

    NARCIS (Netherlands)

    Yin, L.J.; Dong, Juntao; Wang, Yinping; Zhang, Bi; Zhou, Zheng Yang; Jian, Xian; Wu, Mengqiang; Xu, Xin; van Ommen, J.R.; Hintzen, H.T.J.M.

    2016-01-01

    Many strategies have been adopted to improve thermal degradation of phosphors. Because of the stability and high transmittance of graphene, here we report a novel method of carbon coating on BaMgAl10O17:Eu2+ (BAM) phosphor particles through chemical vapor

  20. studies of radiative penguin decays at BaBar

    Indian Academy of Sciences (India)

    We summarize results on a number of observations of penguin dominated radiative decays of the meson. Such decays are forbidden at tree level and proceed via electroweak loops. As such they may be sensitive to physics beyond the standard model. The observations have been made at the BaBar experiment at PEP-II, ...

  1. Measurements of Form Factors with the BaBar Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Li, Selina Z.; /SLAC

    2011-08-25

    Selected recent results on measurements of form factors by the BaBar Collaboration are reviewed, including e{sup +}e{sup -} {yields} {eta}{prime}{gamma}, leptonic and semileptonic charm decays from data collected at or near the {Upsilon}(4S) resonance.

  2. Refugees' perceptions regarding HIV and AIDS in Ba-Phalaborwa ...

    African Journals Online (AJOL)

    2014-10-20

    Oct 20, 2014 ... doi:10.4102/hsag.v19i1.711. Refugees' perceptions regarding HIV and AIDS in. Ba-Phalaborwa Municipality in Limpopo Province. Authors: Elizabeth Nkwinika1. Lunic B. Khoza2. Rachel T. Lebese2. Hildah N. Shilubane2. Affiliations: 1Lulekani Health Centre,. South Africa. 2Department of Advanced.

  3. Proton microbeam irradiation effects on PtBA polymer

    Indian Academy of Sciences (India)

    Unknown

    irradiation effects on poly-tert-butyl-acrylate (PtBA) polymer using 2⋅0 MeV proton microbeam are reported. Preliminary results on pattern ... sist materials: electromagnetic radiation (e.g. optical, UV or X-ray photons) or charged ... a substrate and depending on the positive or negative type of resist material, the exposed or ...

  4. Thermodynamic study on the Sm-Ba-Cu-O system

    Science.gov (United States)

    Xian-ran, Xing; Zhi-yu, Qiao; Shou-kun, Wei; Xiao-long, Chen; Jing-kui, Liang; Guang-hui, Rao

    1996-11-01

    The assembly for EMF measurement with CaF2 single crystal or MgO partially stabilized zirconia as solid state electrolyte has been constructed. From the EMF data, the standard Gibbs energies, standard enthalpies of formation and standard entropies of six complex oxides in the Sm-Ba-Cu-O system were calculated. The decomposition pressures of these complex oxides were derived.

  5. Upconversion emission of BaTiO3: Er nanocrystals

    Indian Academy of Sciences (India)

    Here, we report the dopant concentration and pump-power dependence upconversion emission properties of erbium doped BaTiO3 nanocrystals derived from sol–emulsion–gel method. Green (550 nm) and red (670 nm) upconversion emissions were observed at room temperature from the 4 S 3 / 2 and 4 F 9 / 2 levels of ...

  6. Two-Photon Interactions at Belle and BaBar

    CERN Document Server

    Eidelman, Simon

    2010-01-01

    Results on two-photon physics obtained in experiments at the B factories are discussed. BaBar used single-tag collisions to measure the transition form factor of the 0 meson. Belle studied no-tag collisions to measure cross sections of exclusive production of two baryons and two mesons. Experimental results are confronted with QCD predictions.

  7. The Danish Microbiology Database (MiBa) 2010 to 2013

    DEFF Research Database (Denmark)

    Voldstedlund, M; Haarh, M; Mølbak, K

    2014-01-01

    The Danish Microbiology Database (MiBa) is a national database that receives copies of reports from all Danish departments of clinical microbiology. The database was launched in order to provide healthcare personnel with nationwide access to microbiology reports and to enable real-time surveillance...

  8. Observation of high spin levels in Cs from Ba decay

    Indian Academy of Sciences (India)

    Abstract. The γ- and conversion electron spectra following 131Ba ε-decay are investigated, using. HPGe detector and mini-orange electron spectrometer. Attention is particularly focussed on iden- tifying weak transitions associated with low energy high spin levels in 131Cs level scheme earlier inferred in reaction studies but ...

  9. Potential energy surfaces for Ж = , Ne- Ba nuclei

    Indian Academy of Sciences (India)

    112Ba nu- clei in an axially deformed relativistic mean field approach. A quadratic constraint scheme is applied to determine the complete energy surface for a wide range of the quadrupole deformation. The NL3, NL-RA1 and TM1 parameter sets ...

  10. Nonlinearity parameter B/A of biological tissue ultrasound imaging in echo mode

    Energy Technology Data Exchange (ETDEWEB)

    Toulemonde, M., E-mail: matthieu.toulemonde@creatis.univ-lyon1.fr; Varray, F.; Bernard, A.; Basset, O.; Cachard, C. [Université de Lyon, CREATIS, CNRS UMR 5220, INSERM U1044, INSA-Lyon, Université Claude Bernard Lyon 1 (France)

    2015-10-28

    The nonlinearity B/A parameter influences the distortion of ultrasound waves during their propagation in tissue. Normal and pathological media have different B/A values and this parameter may be used to characterize them. In this paper the multitaper coherent plane wave compounding (MCPWC) is combined with the extended comparative method (ECM) to estimate the B/A parameter in simulation and acquisition. Using plane wave transmission and orthogonal apodization during beam forming improves the B/A estimation and delineation.

  11. Core-corona PSt/P(BA-AA) composite particles by two-stage emulsion polymerization

    Science.gov (United States)

    Xie, Delong; Ren, Xiaolin; Zhang, Xinya; Liao, Shijun

    2016-03-01

    Raspberry-shaped composite particles with polystyrene (PSt) as core and poly(n-butyl acrylate-co-acrylic acid) (P(BA-AA)) as corona were synthesized via emulsion polymerization. The random copolymer, P(BA-AA), was pre-prepared and used as a polymeric surfactant, its emulsifying properties adjusted by changing the mass ratio of BA and AA. The morphology of the resulting core-corona composite particles, P(St/P(BA-AA)), could be regulated and controlled by varying the concentrations of P(BA-AA) or the mass ratio of BA:AA in P(BA-AA). The experimental results indicate that 3.0-6.0 wt% of P(BA-AA) is required to obtain stable composite emulsions, and P(BA-AA) with a mass ratio of BA:AA = 1:2 is able to generate distinct core-corona structures. A mechanism of composite particle formation is proposed based on the high affinity between the PSt core and the hydrophobic segments of P(BA-A). The regular morphology of the colloidal film is expected to facilitate potential application of core-corona particles in the field of light scattering. Furthermore, the diversity of core-corona particles can be expanded by replacing P(BA-AA) corona particles with other amphiphilic particles.

  12. X-ray excited optical luminescence studies on the system BaXY (X ...

    Indian Academy of Sciences (India)

    The present paper reports the experimental observations on the x-ray excited optical luminescence (XEOL) along with the afterglow and colour center features found for the barium salts, represented by the formula, Ba, where and are the halides. The system thus consists of four dihalides (BaF2, . . . ,BaI2) and six ...

  13. Crystallization of the HigBA2 toxin-antitoxin complex from Vibrio cholerae

    DEFF Research Database (Denmark)

    Hadǽi, San; Garcia-Pino, Abel; Martinez-Rodriguez, Sergio

    2013-01-01

    The genome of Vibrio cholerae encodes two higBA toxin-antitoxin (TA) modules that are activated by amino-acid starvation. Here, the TA complex of the second module, higBA2, as well as the C-terminal domain of the corresponding HigA2 antitoxin, have been purified and crystallized. The HigBA2 complex...

  14. 40 CFR 721.10010 - Barium manganese oxide (BaMnO3).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Barium manganese oxide (BaMnO3). 721... Substances § 721.10010 Barium manganese oxide (BaMnO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as barium manganese oxide (BaMnO3) (PMN P-00...

  15. A study on the damping capacity of BaTiO3-reinforced Al-matrix ...

    Indian Academy of Sciences (India)

    To study the damping capacity of BaTiO 3 /Al composites, Al composites reinforced with BaTiO 3 powder (average grain sizes: 100 and 1000 nm) were fabricated by the hot-pressing sintering method. The damping properties of pure Al and BaTiO 3 /Al composites were investigated and compared based on the dynamic ...

  16. Complete Genome Sequence of the Methanogen Methanoculleus bourgensis BA1 Isolated from a Biogas Reactor.

    Science.gov (United States)

    Maus, Irena; Wibberg, Daniel; Winkler, Anika; Pühler, Alfred; Schnürer, Anna; Schlüter, Andreas

    2016-06-23

    Methanoculleus bourgensis BA1, a hydrogenotrophic methanogen, was isolated from a laboratory-scale biogas reactor operating under an elevated ammonium concentration. Here, the complete genome sequence of M. bourgensis BA1 is reported. The availability of the BA1 genome sequence enables detailed comparative analyses involving other Methanoculleus spp. representing important members of microbial biogas communities. Copyright © 2016 Maus et al.

  17. Stellar Laboratories: 3. New Ba 5, Ba 6, and Ba 7 Oscillator Strengths and the Barium Abundance in the Hot White Dwarfs G191-B2B and RE 0503-289

    Science.gov (United States)

    Rauch, T.; Werner, K.; Quinet, P.; Kruk, Jeffrey Walter

    2014-01-01

    Context. For the spectral analysis of high-resolution and high-signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. Reliable Ba 5-7 oscillator strengths are used to identify Ba lines in the spectra of the DA-type white dwarf G191-B2B and the DO-type white dwarf RE 0503-289 and to determine their photospheric Ba abundances. Methods. We newly calculated Ba v-vii oscillator strengths to consider their radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models for the analysis of Ba lines exhibited in high-resolution and high-S/N UV observations of G191-B2B and RE 0503-289. Results. For the first time, we identified highly ionized Ba in the spectra of hot white dwarfs. We detected Ba vi and Ba vii lines in the Far Ultraviolet Spectroscopic Explorer (FUSE) spectrum of RE 0503-289. The Ba vi/Ba vii ionization equilibrium is well reproduced with the previously determined effective temperature of 70 000 K and surface gravity of log g=7.5. The Ba abundance is 3.5 +/- 0.5 × 10(exp-4) (mass fraction, about 23 000 times the solar value). In the FUSE spectrum of G191-B2B, we identified the strongest Ba vii line (at 993.41 Å) only, and determined a Ba abundance of 4.0 +/- 0.5 × 10(exp-6) (about 265 times solar). Conclusions. Reliable measurements and calculations of atomic data are a pre-requisite for stellar-atmosphere modeling. Observed Ba vi-vii line profiles in two white dwarfs' (G191-B2B and RE 0503-289) far-ultraviolet spectra were well reproduced with our newly calculated oscillator strengths. This allowed to determine the photospheric Ba abundance of these two stars precisely.

  18. Antiferromagnetic structure and electronic properties of BaCr2As2 and BaCrFeAs2

    Science.gov (United States)

    Filsinger, Kai A.; Schnelle, Walter; Adler, Peter; Fecher, Gerhard H.; Reehuis, Manfred; Hoser, Andreas; Hoffmann, Jens-Uwe; Werner, Peter; Greenblatt, Martha; Felser, Claudia

    2017-05-01

    Recent theoretical studies suggest that superconductivity may be found in doped chromium pnictides with crystal structures similar to their iron counterparts. Here, we report a comprehensive study on the magnetic arsenides BaCr2As2 and BaCrFeAs2 (space group I 4 /m m m ), which are possible mother compounds with d4 and d5 electron configurations, respectively. DFT-based calculations of the electronic structure evidence metallic antiferromagnetic ground states for both compounds. By powder neutron diffraction, we confirm for BaCr2As2 a robust ordering in the antiferromagnetic G -type structure at TN=580 K with μCr=1.9 μB . Anomalies in the lattice parameters point to magnetostructural coupling effects. In BaCrFeAs2, the Cr and Fe atoms randomly occupy the transition-metal site and G -type order is found below 265 K with μCr /Fe=1.1 μB . 57Fe Mössbauer spectroscopy demonstrates that only a small ordered moment is associated with the Fe atoms, in agreement with electronic structure calculations leading to μFe˜0 . The temperature dependence of the hyperfine field does not follow that of the total moments. Both compounds are metallic but show large enhancements of the linear specific heat. Electrical transport in BaCrFeAs2 is dominated by the atomic disorder and the partial magnetic disorder of Fe. Our results indicate that Néel-type order is unfavorable for Fe moments and thus it is destabilized with increasing Fe content.

  19. The effects of BaSO₄ loading on OPC cementing system for encapsulation of BaSO₄ scale from oil and gas industry.

    Science.gov (United States)

    Hussein, O; Utton, C; Ojovan, M; Kinoshita, H

    2013-10-15

    The BaSO4 scales obtained from piping decontamination from oil and gas industries are most often classified as low level radioactive waste. These wastes could be immobilised by stable cement matrix to provide higher safety of handling, transportation, storage and disposal. However, the information available for the effects of the basic formulation such as waste loading on the fundamental properties is still limited. The present study investigated the effect of BaSO4 loading and water content on the properties of OPC-BaSO4 systems containing fine BaSO4 powder and coarse granules. The BaSO4 with different particle size had a marked effect on the compressive strength due to their different effects on hydration products formed. Introduction of fine BaSO4 powder resulted in an increased formation of CaCO3 in the system, which significantly contributed to the compressive strength of the products. Amount of water was important to control the CaCO3 formation, and water to cement ratio of 0.53 was found to be a good level to maintain a low porosity of the products both for fine BaSO4 powder and coarse BaSO4 granule. BaSO4 loading of up to 60 wt% has been achieved satisfying the minimum compressive strength of 5 MPa required for the radioactive wasteforms. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Experimental investigation of decay properties of neutron deficient $^{116-118}$Ba isotopes and test of $^{112-115}$Ba beam counts

    CERN Multimedia

    We propose to study decay of neutron deficient isotopes $^{116-118}$Ba using Double Sided Silicon Strip Detector (DSSSD). To study delayed-proton and $\\alpha$-decay branching ratios of $^{116-118}$Ba are of special interest because of their vicinity to the proton drip line. The nuclear life-times and properties of the proton unstable states of Cs isotopes, populated through decay of $^{116-118}$Ba isotopes will be measured. In addition to that we propose beam development of $^{112-115}$Ba to study exotic decay properties of these neutron deficient nuclei and to search for super-allowed $\\alpha$-decay in future.

  1. Synthesis of the intermetallic clathrate Na2Ba6Si46 by oxidation of Na2BaSi4 with HCl

    Directory of Open Access Journals (Sweden)

    Bodo Böhme, Umut Aydemir, Alim Ormeci, Walter Schnelle, Michael Baitinger and Yuri Grin

    2007-01-01

    Full Text Available A new preparation route to the intermetallic clathrate-I compound Na2Ba6Si46 is introduced, which allows one to make large amounts of product with standard laboratory equipment. The precursor Na2BaSi4 is oxidized with gaseous HCl at 673 K to Na2Ba6Si46, NaCl and BaCl2. Full-profile refinement of the crystal structure from the X-ray powder diffraction data revealed a composition close to Na2Ba6Si46 (Na1.94(1Ba6.06(1Si46, space group Pmbar 3n, a=10.281(1 Å. Differential scanning calorimetry showed an exothermic effect at 874 K, indicating that Na2Ba6Si46 is metastable. The product was additionally characterized by scanning electron microscopy. The electronic structure of Na2Ba6Si46 was investigated by a first-principles, all-electron full-potential method, predicting metallic conductivity. Na2Ba6Si46 obtained by oxidation with HCl shows Pauli paramagnetism; no bulk superconductivity was found down to 1.8 K in a magnetic field of 20 Oe.

  2. Synthesis, crystal growth and structure, magnetic and electrical properties of Ba4Ru2FeO10 and Ba4Ru2CoO10

    Science.gov (United States)

    Shlyk, L.; Niewa, R.

    2013-05-01

    Crystals of Ba4Ru2FeO10 and Ba4Ru2CoO10 (Cmca, Z = 4, Ba4Ru2FeO10: a = 5.7899(1) Å, b = 13.2898(3) Å, c = 13.0098(4) Å, V = 1001.06 Å3; Ba4Ru2CoO10: a = 5.7691(2) Å, b = 13.2061(3) Å, c = 12.9755(4) Å, V = 988.57 Å3) were obtained from binary oxides and BaCoO3 at 1300 °C. Both compounds crystallize isostructural to Ba4Ru3O10 with different preference of the 3d metal at the two crystallographic sites of Ru in the parent compound. Ba4Ru2FeO10 exhibits a spin-glass like transition at 25 K, while Ba4Ru2CoO10 does not show any magnetic order down to 2 K. According to electrical resistivity measurements performed on single crystals both compounds are semiconductors. In contrast to the variable-range hopping of the transport mechanism of Co bearing material, the electrical resistivity of Ba4Ru2FeO10 follows an activation law resulting in a band gap of approximately 0.98 eV.

  3. Influence of Impurities on the Luminescence of Er3+ Doped BaTiO3 Nanophosphors

    Directory of Open Access Journals (Sweden)

    G. D. Webler

    2014-01-01

    Full Text Available The influence of the presence of barium carbonate (BaCO3 phase on the luminescence properties of barium titanate nanocrystals (BaTiO3 powders was investigated. Structural and optical characterizations of erbium (Er3+ doped BaTiO3 synthesized by the sol-emulsion-gel were performed. Using Fourier transform infrared spectroscopy and X-ray powder diffraction, we identified the presence of impurities related to BaCO3 and quantified its fraction. It was observed that the presence of BaCO3 phase, even at low levels, depletes significantly the infrared-to-visible upconverted luminescence efficiency of the produced nanopowders.

  4. BaH molecular spectroscopy with relevance to laser cooling

    CERN Document Server

    Tarallo, M G; Zelevinsky, T

    2015-01-01

    We describe a simple experimental apparatus for laser ablation of barium monohydride (BaH) molecules and the study of their rovibrational spectra that are relevant to direct laser cooling. We present a detailed analysis of the properties of ablation plumes that can improve the understanding of surface ablation and deposition technologies. A range of absorption spectroscopy and collisional thermalization regimes has been studied. We directly measured the Franck-Condon factor of the $\\mathrm{B}^2\\Sigma^+(v'=0)\\leftarrow\\mathrm{X}^2\\Sigma^+(v"=1)$ transition. Prospects for production of a high luminosity cryogenic BaH beam are outlined. This molecule is a promising candidate for laser cooling and ultracold fragmentation, both of which are precursors to novel experiments in many-body physics and precision measurement.

  5. Magnetization analysis of Ba ferrite magnets by electron holography

    Energy Technology Data Exchange (ETDEWEB)

    Aiso, T. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 1-1 Katahira, 2-Chome, Aobaku, Sendai 980-8577 (Japan); Shindo, D. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 1-1 Katahira, 2-Chome, Aobaku, Sendai 980-8577 (Japan)]. E-mail: shindo@tagen.tohoku.ac.jp; Sato, T. [NEC TOKIN Techno Service Ltd., 6-7-1 Koriyama, Taihaku-ku, Miyagi 982-8510 (Japan)

    2007-11-15

    The magnetization distributions of anisotropic and isotropic Ba ferrite magnets in demagnetized and remanent states are investigated by electron holography. A polar diagram is used to obtain the quantitative mapping of the magnetization distribution. Through the polar diagrams, it is clarified that the magnetization distribution of Ba ferrite magnets closely depends on their magnetic properties. The dispersions of the magnetization direction of the two specimens in the remanent states correlate well with their remanent flux density. In the anisotropic specimen, the magnetization reversal occurs drastically under an applied field of 360 kA/m, while in the isotropic one, the direction of magnetization changes gradually. The results exhibit a good correspondence between the change in the magnetization distribution and the shape of the demagnetization curves.

  6. Performances of RPCs in the BaBar Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Messner, Robert

    2003-09-26

    The BaBar experiment uses a big system based on RPC detectors to discriminate muons from pions and to identify neutral hadrons. About 2000 m{sup 2} of RPC chambers have been working at SLAC since the end of 1998. We report on the performances of the RPC chambers focusing on new problems discovered in the RPC behavior. These problems started very soon after the installation of the chambers on the detector when the high ambient temperature triggered an increase of dark currents inside the chambers and a reduction of the efficiency. Careful analysis of the BaBar data and dedicated R&D efforts in the laboratory have helped to identify the main source of the trouble in the linseed oil varnish on the bakelite electrodes.

  7. Thermoelectric properties of topological insulator BaSn2

    Science.gov (United States)

    Guo, San-Dong; Qiu, Liang

    2017-01-01

    Recently, \\text{BaS}{{\\text{n}}2} has been predicted to be a strong topological insulator by the first-principle calculations. It is well known that topological insulators have a close connection to thermoelectric materials, such as the \\text{B}{{\\text{i}}2}\\text{T}{{\\text{e}}3} family. In this work, we investigate thermoelectric properties of \\text{BaS}{{\\text{n}}2} by the first-principles calculations combined with the Boltzmann transport theory. The electronic part is carried out by a modified Becke and Johnson (mBJ) exchange potential, including spin-orbit coupling (SOC), while the phonon part is performed using a generalized gradient approximation (GGA). It was found that the electronic transport coefficients between the in-plane and cross-plane directions showed strong anisotropy, while lattice-lattice thermal conductivities demonstrated almost complete isotropy. Calculated results revealed a very low lattice thermal conductivity for \\text{BaS}{{\\text{n}}2} , and the corresponding average lattice thermal conductivity at room temperature is 1.69 \\text{W}~{{\\text{m}}-1}~{{\\text{K}}-1} , which is comparable or lower than those of lead chalcogenides and bismuth-tellurium systems as classic thermoelectric materials. Due to the complicated scattering mechanism, calculating the scattering time τ is challenging. By using an empirical τ ={{10}-14} s, the n-type figure of merit ZT is greater than 0.40 in wide temperature ranges. Experimentally, it is possible to attain better thermoelectric performance by strain or tuning size parameters. This work indicates that \\text{BaS}{{\\text{n}}2} may be a potential thermoelectric material, which can stimulate further theoretical and experimental work.

  8. Earth Observation for Biodiversity Assessment (EO-BA)

    CSIR Research Space (South Africa)

    Cho, Moses A

    2012-10-01

    Full Text Available of air and water ? Protection of watershed, soil erosion and floods ? Nutrient cycling ? Biomass storage ? Provision of food, water, fuel and energy, raw materials and genetic resources for the pharmaceutical industry ? Cultural services. The role... Observation for Biodiversity Assessment (EO-BA) programme is designed to enhance biodiversity assessment and conservation through the application of earth observation data, with particular focus on the African continent. MISSION To initiate and develop...

  9. Ultrasonic Investigations on Polonides of Ba, Ca, and Pb

    Science.gov (United States)

    Singh, Devraj; Bhalla, Vyoma; Bala, Jyoti; Wadhwa, Shikha

    2017-10-01

    The temperature-dependent mechanical and ultrasonic properties of barium, calcium, and lead polonides (BaPo, CaPo, and PbPo) were investigated in the temperature range 100-300 K. The second- and third-order elastic constants (SOECs and TOECs) were computed using Coulomb and Born-Mayer potential and these in turn have been used to estimate other secondary elastic properties such as strength, anisotropy, microhardness, etc. The theoretical approach followed the prediction that BaPo, CaPo, and PbPo are brittle in nature. PbPo is found to be the hardest amongst the chosen compounds. Further the SOECs and TOECs are applied to determine ultrasonic velocities, Debye temperature, and acoustic coupling constants along , , and orientations at room temperature. Additionally thermal conductivity has been computed using Morelli and Slack's approach along different crystallographic directions at room temperature. Finally ultrasonic attenuation due to phonon-phonon interaction and thermoelastic relaxation mechanisms has been computed for BaPo, CaPo, and PbPo. The behaviour of these compounds is similar to that of semi-metals with thermal relaxation time of the order 10-11 s. The present computation study is reasonably in agreement with the available theoretical data for the similar type of materials.

  10. Analysis of Jupiter's Oval BA: A Streamlined Approach

    Science.gov (United States)

    Sussman, Michael G.; Chanover, Nancy J.; Simon-Miller, Amy A.; Vasavada, Ashwin R.; Beebe, Reta F.

    2010-01-01

    We present a novel method of constructing streamlines to derive wind speeds within jovian vortices and demonstrate its application to Oval BA for 2001 pre-reddened Cassini flyby data, 2007 post-reddened New Horizons flyby data, and 1998 Galileo data of precursor Oval DE. Our method, while automated, attempts to combine the advantages of both automated and manual cloud tracking methods. The southern maximum wind speed of Oval BA does not show significant changes between these data sets to within our measurement uncertainty. The northern maximum dries appear to have increased in strength during this time interval, tvhich likely correlates with the oval's return to a symmetric shape. We demonstrate how the use of closed streamlines can provide measurements of vorticity averaged over the encircled area with no a priori assumptions concerning oval shape. We find increased averaged interior vorticity between pre- and post-reddened Oval BA, with the precursor Oval DE occupying a middle value of vorticity between these two.

  11. Synthesis and characterization of (Ba,Yb doped ceria nanopowders

    Directory of Open Access Journals (Sweden)

    Branko Matović

    2011-06-01

    Full Text Available Nanometric size (Ba, Yb doped ceria powders with fluorite-type structure were obtained by applying selfpropagating room temperature methods. Tailored composition was: Ce0.95−xBa0.05YbxO2−δ with fixed amount of Ba − 0.05 and varying Yb content “x” from 0.05 to 0.2. Powder properties such as crystallite and particle size and lattice parameters have been studied. Röntgen diffraction analyses (XRD were used to characterize the samples at room temperature. Also, high temperature treatment (up to 1550°C was used to follow stability of solid solutions. The mean diameters of the nanocrystals are determined from the full width at half maxima (FWHM of the XRD peaks. It was found that average diameter of crystallites is less than 3 nm. WilliamsonHall plots were used to separate the effect of the size and strain in the nanocrystals.

  12. Peixes recifais da costa da Paraíba, Brasil Reef fishes from Paraíba, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz A. Rocha

    1998-01-01

    Full Text Available The coral reef is an ecossystem which evokes great interest, for its beaury, species diversity and fisheries potential. The coast of Paraíba State, northeast Brazil, possesses several natural reefs and shipwrecks which are inhabited by a rich fish fauna. In order to survey the reef fish fauna of Paraíba State, a total of 118 dives, utilizing SCUBA diving techniques, were carriedoutin 27samplingpoints (depths: 0,5-66m, from February/1995 to May/1996. Specimens were collected whenever underwater identification was precluded. A total of 157 known species belonging to 59 families were found. Four unidentified species, one dasyatid, one haemulid, one scarid, and one labrid were recorded. Haemulidae was the most representative family in number of individuais, whereas Carangidae was the most speciose family. This paper is part of a broader study of the northeast Brazilian reef fishes.

  13. High-pressure synthesis of the cubic perovskite BaRuO3 and evolution of ferromagnetism in ARuO3 (A = Ca, Sr, Ba) ruthenates

    Science.gov (United States)

    Jin, C.-Q.; Zhou, J.-S.; Goodenough, J. B.; Liu, Q. Q.; Zhao, J. G.; Yang, L. X.; Yu, Y.; Yu, R. C.; Katsura, T.; Shatskiy, A.; Ito, E.

    2008-01-01

    The cubic perovskite BaRuO3 has been synthesized under 18 GPa at 1,000°C. Rietveld refinement indicates that the new compound has a stretched Ru–O bond. The cubic perovskite BaRuO3 remains metallic to 4 K and exhibits a ferromagnetic transition at Tc = 60 K, which is significantly lower than the Tc ≈ 160 K for SrRuO3. The availability of cubic perovskite BaRuO3 not only makes it possible to map out the evolution of magnetism in the whole series of ARuO3 (A = Ca, Sr, Ba) as a function of the ionic size of the A-site rA, but also completes the polytypes of BaRuO3. Extension of the plot of Tc versus rA in perovskites ARuO3 (A = Ca, Sr, Ba) shows that Tc does not increase as the cubic structure is approached, but has a maximum for orthorhombic SrRuO3. Suppressing Tc by Ca and Ba doping in SrRuO3 is distinguished by sharply different magnetic susceptibilities χ(T) of the paramagnetic phase. This distinction has been interpreted in the context of a Griffiths' phase on the (Ca Sr)RuO3 side and bandwidth broadening on the (Sr,Ba)RuO3 side. PMID:18480262

  14. Optical and structural properties of Eu 2 + doped BaBrI and BaClI crystals

    Science.gov (United States)

    Shendrik, R.; Shalaev, A. A.; Myasnikova, A. S.; Bogdanov, A.; Kaneva, E.; Rusakov, A.; Vasilkovskyi, A.

    2017-12-01

    The work is necessitated by search for new materials to detect ionizing radiation. The rare-earth ions doped with ternary alkali earth-halide systems are promising scintillators showing high efficiency and energy resolution. Some aspects of crystal growth and data on the structural and luminescence properties of BaBrI and BaClI doped with low concentrations of $\\mathrm{Eu^{2+}}$ ions are reported. The crystals are grown by the vertical Bridgman method in sealed quartz ampoule. New crystallography data for BaClI single crystal obtained by single crystal X-ray diffraction method are presented in this paper. Emission, excitation and optical absorption spectra as well as luminescence decay kinetics are studied under excitation by X-ray, vacuum ultraviolet and ultraviolet radiation. The energies of the first 4f-5d transition in $\\mathrm{Eu^{2+}}$ and band gap of the crystals have been obtained. We have calculated the electronic band structure of the crystals using density functional theory as implemented in the \\latin{Ab Initio}. Calculated band gap energies are in accord with the experimental estimates. The energy of gaps between the occupied Eu$^{2+}$ 4f level and the valence band top are predicted. In addition, positions of lanthanide energy levels in relation to valence band have been constructed using the chemical shift model.

  15. Reproducibility of Ba/Ca variations recorded by northeast Pacific bamboo corals

    Science.gov (United States)

    Serrato Marks, G.; LaVigne, M.; Hill, T. M.; Sauthoff, W.; Guilderson, T. P.; Roark, E. B.; Dunbar, R. B.; Horner, T. J.

    2017-09-01

    Trace elemental ratios preserved in the calcitic skeleton of bamboo corals have been shown to serve as archives of past ocean conditions. The concentration of dissolved barium (BaSW), a bioactive nutrientlike element, is linked to biogeochemical processes such as the cycling and export of nutrients. Recent work has calibrated bamboo coral Ba/Ca, a new BaSW proxy, using corals spanning the oxygen minimum zone beneath the California Current System. However, it was previously unclear whether Ba/Cacoral records were internally reproducible. Here we investigate the accuracy of using laser ablation inductively coupled plasma mass spectrometry for Ba/Cacoral analyses and test the internal reproducibility of Ba/Ca among replicate radial transects in the calcite of nine bamboo corals collected from the Gulf of Alaska (643-720 m) and the California margin (870-2054 m). Data from replicate Ba/Ca transects were aligned using visible growth bands to account for nonconcentric growth; smoothed data were reproducible within 4% for eight corals (n = 3 radii/coral). This intracoral reproducibility further validates using bamboo coral Ba/Ca for BaSW reconstructions. Sections of the Ba/Ca records that were potentially influenced by noncarbonate bound Ba phases occurred in regions where elevated Mg/Ca or Pb/Ca and coincided with anomalous regions on photomicrographs. After removing these regions of the records, increased Ba/Cacoral variability was evident in corals between 800 and 1500 m. These findings support additional proxy validation to understand BaSW variability on interannual timescales, which could lead to new insights into deep sea biogeochemistry over the past several centuries.

  16. Flora da Paraíba, Brasil: Solanum L. (Solanaceae Flora of Paraíba, Brazil: Solanum L. (Solanaceae

    Directory of Open Access Journals (Sweden)

    Maria de Fátima Agra

    2009-09-01

    Full Text Available Neste trabalho apresenta-se o tratamento taxonômico do gênero Solanum, como parte do projeto "Flora da Paraíba", que vem sendo realizado com o objetivo de identificar e catalogar as espécies da flora local. Realizaram-se coletas, observações de campo e estudos morfológicos para as identificações, descrições e ilustrações botânicas, com o auxílio da bibliografia especializada, complementadas pela análise de tipos e fotos de tipos de herbários nacionais e internacionais e de espécimes depositados nos herbários EAN e JPB. Foram registradas 22 espécies: Solanum agrarium Sendtn., S. americanum Mill., S. asperum Rich., S. asterophorum Mart., S. caavurana Vell., S. capsicoides All., S. crinitum Lam., S. jabrense Agra & M.Nee, S. melissarum Bohs, S. ovum-fringillae (Dunal Bohs, S. palinacanthum Dunal, S. paludosum Moric., S. paniculatum L., S. paraibanum Agra, S. polytrichum Moric., S. rhytidoandrum Sendtn., Solanum sp., S. stagnale Moric., S. stipulaceum Roem. & Schult., S. stramoniifolium Jacq., S. swartzianum Roem. & Schult. e S. torvum Sw. Três espécies, S. ovum-fringillae, Solanum sp. e S. swartzianum, são novas referências para a Paraíba.A taxonomic treatment of the genus Solanum was done as part of the project "Flora da Paraíba", which aims to identify and catalogue the species of the local flora. Botanical collections, field observations and morphological studies were done for identification, description and botanical illustration of the plant species, supported by the literature and analysis of national and foreign herbaria, and specimens from EAN and JPB. Twenty two species of Solanum were recorded in State of Paraíba, as follows: Solanum agrarium Sendtn., S. americanum Mill., S. asperum Rich., S. asterophorum Mart., S. caavurana Vell., S. capsicoides All., S. crinitum Lam., S. jabrense Agra & M.Nee, S. melissarum Bohs, S. ovum-fringillae (Dunal Bohs, S. palinacanthum Dunal, S. paludosum Moric., S. paniculatum L., S

  17. Growth of single crystals of BaFe12O19 by solid state crystal growth

    Science.gov (United States)

    Fisher, John G.; Sun, Hengyang; Kook, Young-Geun; Kim, Joon-Seong; Le, Phan Gia

    2016-10-01

    Single crystals of BaFe12O19 are grown for the first time by solid state crystal growth. Seed crystals of BaFe12O19 are buried in BaFe12O19+1 wt% BaCO3 powder, which are then pressed into pellets containing the seed crystals. During sintering, single crystals of BaFe12O19 up to ∼130 μm thick in the c-axis direction grow on the seed crystals by consuming grains from the surrounding polycrystalline matrix. Scanning electron microscopy-energy dispersive spectroscopy analysis shows that the single crystal and the surrounding polycrystalline matrix have the same chemical composition. Micro-Raman scattering shows the single crystal to have the BaFe12O19 structure. The optimum growth temperature is found to be 1200 °C. The single crystal growth behavior is explained using the mixed control theory of grain growth.

  18. Left posterior BA37 is involved in object recognition: a TMS study

    DEFF Research Database (Denmark)

    Stewart, Lauren; Meyer, Bernd-Ulrich; Frith, Uta

    2001-01-01

    Functional imaging studies have proposed a role for left BA37 in phonological retrieval, semantic processing, face processing and object recognition. The present study targeted the posterior aspect of BA37 to see whether a deficit, specific to one of the above types of processing could be induced...... to name pictures when TMS was given over lBA37 compared to vertex or rBA37. rTMS over lBA37 had no significant effect on word reading, nonword reading or colour naming. The picture naming deficit is suggested to result from a disruption to object recognition processes. This study corroborates the finding...... from a recent imaging study, that the most posterior part of left hemispheric BA37 has a necessary role in object recognition....

  19. Quo Vadis the B.A. degree: Perceptions and visions1

    Directory of Open Access Journals (Sweden)

    Annette L. Combrink

    1993-03-01

    Full Text Available Today is a very special day for all the graduates assembled to have a B.A. degree conferred on them. It is a day on which to celebrate the reward for hard work and for realized dreams. This is a very homogeneous group of people - in the sense that they will be receiving B.A. degrees, and for that reason it would be highly apposite to share some cherished thought and ideas about the B.A. degree.

  20. Impacts of Mining and Urbanization on the Qin-Ba Mountainous Environment, China

    OpenAIRE

    Xinliang Xu; Hongyan Cai; Daowei Sun; Lan Hu; Kwamina E. Banson

    2016-01-01

    The Qin-Ba Ecological Functional Zone is a component of China’s ecological security pattern designed to protect the regional ecosystem and maintain biodiversity. However, due to the impact of mining and urban encroachment, the plight of a sustainable ecosystem in the Qin-Ba mountainous area is deteriorating. This paper has used a remote sensing and geographic information system (GIS) to examine the impacts of mining and urban encroachment on the environment in the Qin-Ba mountainous area. The...

  1. THINNING OF ‘GALA’ AND 'GOLDEN DELICIOUS' APPLES WITH BA, NAA AND THEIR COMBINATIONS

    Directory of Open Access Journals (Sweden)

    M STOPAR

    2002-07-01

    Full Text Available Apple trees, eight-year-old ‘Gala’/M.9 and four-year-old ‘Golden Delicious’/M.9 have been thinned with 6- benzyladenine (BA 50 ppm, 100 ppm and 200 ppm, with 1-naphthaleneacetic acid (NAA 5 ppm, 10 ppm and 20 ppm, and with the tank mix combinations of BA 50 ppm + NAA 5 ppm or BA 20 ppm + NAA 5 ppm, all at 9-10 mm fruitlet diameter. All applied concentrations of BA and NAA thinned both cultivars significantly and no significant difference was found between BA or NAA thinning action. No concentration response on thinning was observed with neither BA nor NAA application. All BA or NAA separate treatments caused yield of fruit to shift to bigger size class. The only concentration response effect was found on evaluation of mean fruit weight data on ‘Golden Delicious’. The higher concentration of BA was used, the higher was the weight of ‘Golden Delicious’ fruit. On the opposite, the higher concentration of NAA was used, the lower was the weight of ‘Golden Delicious’ fruit (not significantly. When BA and NAA were sprayed on ‘Gala’ or ‘Golden Delicious’ as a tank mix combination, similar effect on thinning or fruit growth occurred comparing to BA or NAA when sprayed alone. Return bloom was enhanced on all thinned ‘Gala’ trees while flower formation of ‘Golden Delicious’ was better in the case of BA 200 ppm, NAA 5 ppm, NAA 20 ppm or tank mix spraying of BA 20 ppm + NAA 5 ppm.

  2. Ba{sub 2}TeO: A new layered oxytelluride

    Energy Technology Data Exchange (ETDEWEB)

    Besara, T. [National High Magnetic Field Laboratory, Condensed Matter Sciences Department, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310 (United States); Ramirez, D. [National High Magnetic Field Laboratory, Condensed Matter Sciences Department, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310 (United States); Florida Agricultural and Mechanical University—Florida State University College of Engineering, Department of Chemical and Biomedical Engineering, 2525 Pottsdamer St., Tallahassee, FL 32310 (United States); Sun, J. [National High Magnetic Field Laboratory, Condensed Matter Sciences Department, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310 (United States); Florida Agricultural and Mechanical University—Florida State University College of Engineering, Department of Chemical and Biomedical Engineering, 2525 Pottsdamer St., Tallahassee, FL 32310 (United States); Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831 (United States); Whalen, J.B. [National High Magnetic Field Laboratory, Condensed Matter Sciences Department, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310 (United States); Specialized Crystal Processing, Inc., 400 Capital Circle SE, Suite 18227, Tallahassee, FL 32301 (United States); Tokumoto, T.D.; McGill, S.A. [National High Magnetic Field Laboratory, Condensed Matter Sciences Department, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310 (United States); Singh, D.J. [Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831 (United States); Siegrist, T. [National High Magnetic Field Laboratory, Condensed Matter Sciences Department, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310 (United States); Florida Agricultural and Mechanical University—Florida State University College of Engineering, Department of Chemical and Biomedical Engineering, 2525 Pottsdamer St., Tallahassee, FL 32310 (United States)

    2015-02-15

    Single crystals of the new semiconducting oxytelluride phase, Ba{sub 2}TeO, were synthesized from barium oxide powder and elemental tellurium in a molten barium metal flux. Ba{sub 2}TeO crystallizes in tetragonal symmetry with space group P4/nmm (#129), a=5.0337(1) Å, c=9.9437(4) Å, Z=2. The crystals were characterized by single crystal x-ray diffraction, heat capacity and optical measurements. The optical measurements along with electronic band structure calculations indicate semiconductor behavior with a band gap of 2.93 eV. Resistivity measurements show that Ba{sub 2}TeO is highly insulating. - Graphical abstract: Starting from a simple stacking of rocksalt layers, the final structure of Ba{sub 2}TeO can be obtained by accommodation of structural strain via atom displacements. Density of states calculations and optical absorbance measurements show that Ba{sub 2}TeO has a band gap of 2.93 eV, indicative of semiconductor behavior. - Highlights: • Single crystal synthesis of a new layered oxytelluride, Ba{sub 2}TeO. • The structure features inverse PbO-type BaO layers and NaCl-type BaTe layers. • Optical absorbance show Ba{sub 2}TeO to be a semiconductor with a 2.93 eV gap. • Density of states indicate a small hybridization between Te 5p and Ba 5d states. • The BaTe (BaO) layers dominate the heat capacity at low (high) temperatures.

  3. Epitaxial growth and spectroscopic investigation of BaSO4:Mn6+ layers

    NARCIS (Netherlands)

    Ehrentraut, D.; Pollnau, Markus; Kück, S.

    2002-01-01

    We report on the first layer growth of a Mn6+-doped material. Large-size BaSO4 substrates of 10×6×4 mm3 were grown from a LiCl solvent by the flux method. Flat surfaces of undoped BaSO4 were then achieved by use of liquid-phase epitaxy (LPE) from a CsCl–KCl–NaCl solvent. Finally, BaSO4:Mn6+ layers

  4. Medication safety in pregnancy : results from the MoBa study

    OpenAIRE

    Hedvig Nordeng; Eivind Ystrom; Malin Eberhard-Gran

    2014-01-01

    This article summarizes the results of several of our studies on medication safety in pregnancy based on the Norwegian Mother and Child Cohort Study (MoBa). Medications investigated include antidepressants, NSAIDs, codeine, triptans, paracetamol and certain herbals. A major advantage of these studies is that MoBa has information on prescribed medications, over-the-counter medications and herbal medications. Moreover, MoBa enables the possibility of including a disease comparison group, and lo...

  5. NUCLEI OF DESERTIFICATION IN STATE OF PARAÍBA

    Directory of Open Access Journals (Sweden)

    Jose Jakson Amancio Alves

    2009-06-01

    Full Text Available The present work boards desertification problem in Paraíba who directly is related to degradation produced by the man in the stunted sparse forest and in the environmental terms and fitogeography of this geoecosystem. The domain geoecology of the stunted sparse forests extends for about 1037.517,80 km², under the latitudes between tropics, comprehended between 2º 45’ and 17º 21’ LS.  Its area corresponds to 54% of the region Northeast and to 11% of the brazilian territory; it constitutes the droughts called polygon. In the stunted sparse forest the woody species call the attention for their biological forms and by the dominant position in the formation structure. In magnitude function of these characteristic, that corresponds to the largest problem in desertification cores generation in state of Paraíba. These woody species of rickety postage are the appreciated most for the burning in coal-pits, bakeries oven, etc. they are fácies more drought and degraded of the stunted sparse forests. Another aspect to observe is that to the natural fragility of this ecosystem brings serious consequences for geótopos and for biocenoses, as well as, the devastation practice of great spaces by the burnt for the pasture areas, provoking great unbalance in the ecosystem and contributing with the earth’s degradation process. That work points a series of surveys that emphasize that process in state of Paraíba, as well as, a contribution for contention of their effects.

  6. Structure and stability of BaTiSi₂O₇.

    Science.gov (United States)

    Viani, Alberto; Palermo, Andrea; Zanardi, Stefano; Demitri, Nicola; Petrícek, Václav; Varini, Federico; Belluso, Elena; Ståhl, Kenny; Gualtieri, Alessandro Francesco

    2015-04-01

    Due to their optical, photo-luminescence (PL), and afterglow properties, barium titanosilicates are compounds of great interest for functional materials and light-emitting devices. Among them, BaTiSi2O7 (BTS2) is certainly one of the most intriguing; it displays peculiar properties (e.g. PL orange emission) whose exhaustive explanation has been hampered to date by the lack of a structure model. In this work, BTS2 and the related compound BaTiSi4O11 (BTS4) were synthesized through conventional solid-state reaction methods. BTS2 invariably shows complex twinning patterns. Thus, its structure solution and Rietveld structure refinement were attempted using synchrotron powder diffraction. BTS2 was found to be an intergrowth of monoclinic and triclinic crystals. The monoclinic phase has the space group P21/n and unit cell a = 7.9836 (3), b = 10.0084 (4), c = 7.4795 (3) Å, and β = 100.321 (3)°, whereas the triclinic phase has the space group P\\bar 1 and unit cell a = 7.99385 (4), b = 10.01017 (5), c = 7.47514 (3) Å, α = 90.084 (8), β = 100.368 (8) and γ = 89.937 (9)°. These lattices can be seen as a distortion of that of tetragonal synthetic β-BaVSi2O7 with Ti in place of V. The structure models obtained from this study confirm the presence of fivefold coordinated Ti atoms in a distorted pyramidal configuration. The proposed solution supports existing theories for the explanation of the PL orange colour in BTS2.

  7. Neutron diffraction study of the crystal structure of BaMoO{sub 4}: A suitable precursor for metallic BaMoO{sub 3} perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Nassif, V.; Carbonio, R.E. [Univ. Nacional de Cordoba (Argentina). Inst. de Investigaciones en Fisicoquimica; Alonso, J.A. [C.S.I.C., Madrid (Spain). Inst. de Ciencia de Materiales

    1999-08-01

    BaMoO{sub 3}, metallic and Pauli paramagnetic, has been prepared by controlled reduction of BaMoO{sub 4}. This precursor, containing Mo(VI), is unusually stable against reduction, due to structural factors. The crystal structure of BaMoO{sub 4} has been refined from neutron powder diffraction data: space group I4{sub 1}/a (no. 88), Z = 4, a = 5.5479(9), and c = 12.743(2) {angstrom}. A bond-valence study allowed the authors to detect the presence of slight tensile and compressive stresses in the crystal structure of BaMoO{sub 4}, in which Ba is overbonded and Mo is underbonded. However, this effect is less pronounced than in other AMO{sub 4} oxides with a scheelite structure (A = Ca, Sr, Ba; M = Mo, W): BaMoO{sub 4} contains the M cation exhibiting the closest valence to the nominal value of 6+, suggesting a large covalent contribution to the Mo-O bonds. This observation is coherent with the large thermal stability of this compound against reduction, taking place at temperatures above 920 C in H{sub 2} flow.

  8. Thermal analysis of formation of nano-crystalline BaTiO3 using Ba(NO32 and TiO2

    Directory of Open Access Journals (Sweden)

    Md. Jawed Ansaree

    2015-12-01

    Full Text Available The reaction of Ba(NO32 with TiO2 was studied by thermogravimetric (TG and differential scanning calorimetric (DSC techniques up to 1000 °C and in nitrogen atmosphere. It was found that the formation of BaTiO3 takes place above 600 °C and that precursor mixing time and heating rate have no effect on the reaction temperature. BaTiO3 powder was prepared by calcination of Ba(NO32 and TiO2 precursor mixture at 800 °C for 8 h. X-ray diffraction analysis of the synthesized BaTiO3 confirmed the formation of tetragonal phase with lattice parameters a = 3.9950±0.0003 Å and c = 4.0318±0.0004 Å. Thermal analysis of the synthesized BaTiO3 powder showed weight loss within temperature range 40–1000 °C of only 0.40%. This small amount of weight loss was connected with some impurity phase, and identified as BaCO3 using Fourier transform infrared (FTIR technique.

  9. Towards trapping and laser cooling Ba and La ions

    Science.gov (United States)

    Hankes, Jessie; Nelson, Amanda; Banner, Patrick; Olmschenk, Steven

    2017-04-01

    Trapped atomic ions are one of the leading candidates for applications in quantum information. We are currently working with barium ions (Ba II), directly loaded by laser ablation of a barium titanium oxide target, and laser cooled using visible laser light (650 nm and 494 nm). Motivated by applications of quantum networks, we also present progress towards laser cooling and trapping lanthanum ions (La III), which should enable quantum information protocols at telecom wavelengths for long-distance applications. This research is supported by the Army Research Office, Research Corporation for Science Advancement, and Denison University.

  10. On the compressibility of BaFe(2)AS(2)

    DEFF Research Database (Denmark)

    Jørgensen, J. E.; Olsen, J. S.; Gerward, Leif

    2009-01-01

    BaFe(2)AS(2) has been studied by high-pressure energy dispersive X-ray diffraction. The compression mechanism was found to be highly anisotropic, and a tetragonal to orthorhombic phase transition was observed at about 17 GPa. The length of the a- and c-axes of the tetragonal phase is reduced by 2...... and 11%, respectively, at the transition pressure. Furthermore, an increase in compressibility was observed at about 1 GPa. The zero-pressure bulk modulus was determined to be B-0 = 71(4) GPa using experimental data points in the pressure range from 1 to 16.5 GPa. The experimental results are supported...

  11. Crystal structure of Ba5In4Sb6

    Directory of Open Access Journals (Sweden)

    Ming-Yan Pan

    2015-05-01

    Full Text Available The title compound, pentabarium tetraindium hexaantimony, was synthesized by an indium-flux reaction and its structure features layers composed of edge-sharing In2Sb6 units. The voids between the In4Sb6 layers are filled by Ba2+ cations, which are all surrounded by six Sb atoms and form bicapped octahedral or triangular prismatic coordination geometries. There are five barium ions in the asymmetric unit: one has no imposed crystallographic symmetry, two lie on mirror planes and two have mm2 point symmetry. The two In atoms and four Sb atoms in the asymmetric unit all lie on general crystallographic positions.

  12. Interdiffusion at the BaCuSeF/ZnTe interface

    Energy Technology Data Exchange (ETDEWEB)

    Zakutayev, Andriy, E-mail: andriy.zakutayev@lifetime.oregonstate.edu [Department of Physics, Oregon State University, Corvallis, OR 97331-6507 (United States); Tate, Janet [Department of Physics, Oregon State University, Corvallis, OR 97331-6507 (United States); Xie Sujing [CAMCOR High Resolution and Analytical Facility, Eugene, OR 97403-1241 (United States); Gibbons, Brady J. [School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, OR 97331-6001 (United States); Platt, Heather A.S.; Keszler, Douglas A. [Department of Chemistry, Oregon State University, Corvallis, OR 97331-6507 (United States); Barati, Alireza; Klein, Andreas; Jaegermann, Wolfram [Department of Materials and Earth Sciences, Darmstadt University of Technology, Darmstadt 64287 (Germany)

    2011-08-31

    BaCuSeF/ZnTe is a model system to investigate physical and chemical properties of the interfaces of non-oxide wide-bandgap p-type semiconductors with materials used in chalcogenide solar cells. The BaCuSeF/ZnTe interface was studied using electron microscopy and photoelectron spectroscopy. Both techniques indicate that Se and Cu from BaCuSeF diffuse into ZnTe creating an interdiffused layer between these two materials. The interdiffusion may be attributed to the differences in materials formation enthalpies and to Fermi level pinning in BaCuSeF.

  13. Synthesis and Characterization of Bowl-Like Single-Crystalline BaTiO3 Nanoparticles

    Science.gov (United States)

    2010-01-01

    Novel bowl-like single-crystalline BaTiO3 nanoparticles were synthesized by a simple hydrothermal method using Ba(OH)2·8H2O and TiO2 as precursors. The as-prepared products were characterized by XRD, Raman spectroscopy, SEM and TEM. The results show that the bowl-like BaTiO3 nanoparticles are single-crystalline and have a size about 100–200 nm in diameter. Local piezoresponse force measurements indicate that the BaTiO3 nanoparticles have switchable polarization at room temperature. The local effective piezoelectric coefficient is approximately 28 pm/V. PMID:20596350

  14. Synthesis and Characterization of Bowl-Like Single-Crystalline BaTiO3 Nanoparticles

    OpenAIRE

    Deng, Zhao; Dai, Ying; Chen, Wen; Pei, Xinmei; Liao, Jihong

    2010-01-01

    Novel bowl-like single-crystalline BaTiO3 nanoparticles were synthesized by a simple hydrothermal method using Ba(OH)2?8H2O and TiO2 as precursors. The as-prepared products were characterized by XRD, Raman spectroscopy, SEM and TEM. The results show that the bowl-like BaTiO3 nanoparticles are single-crystalline and have a size about 100?200 nm in diameter. Local piezoresponse force measurements indicate that the BaTiO3 nanoparticles have switchable polarization at room temperature. The local ...

  15. Enhanced 77 K vortex-pinning in Y Ba2Cu3O7−x films with Ba2Y TaO6 and mixed Ba2Y TaO6 + Ba2Y NbO6 nano-columnar inclusions with irreversibility field to 11 T

    Directory of Open Access Journals (Sweden)

    F. Rizzo

    2016-06-01

    Full Text Available Pulsed laser deposited thin Y Ba2Cu3O7−x (YBCO films with pinning additions of 5 at. % Ba2Y TaO6 (BYTO were compared to films with 2.5 at. % Ba2Y TaO6 + 2.5 at. % Ba2Y NbO6 (BYNTO additions. Excellent magnetic flux-pinning at 77 K was obtained with remarkably high irreversibility fields greater than 10 T (YBCO-BYTO and 11 T (YBCO-BYNTO, representing the highest ever achieved values in YBCO films.

  16. Identifikasi Bakteri Asam Laktat dan Aktivitas Penghambatan Radikal pada Jaruk Tigarun (Crataeva nurvala, Buch Ham (Identification of Lactic Acid Bacteria and Radical Scavenging Activity in Jaruk Tigarun (Crataeva nurvala, Buch HAM

    Directory of Open Access Journals (Sweden)

    Narzani Rahmi

    2016-12-01

    Full Text Available Jaruk tigarun is a traditional fermented food from South Borneo made from tigarun flower that was fermented in water without salt addition. The objectives of the research were to isolate and identify the Lactic Acid Bacteria (LAB from jaruk tigarun then to determine the DPPH radical scavenging activities of jaruk tigarun extracts. LAB was isolated from jaruk tigarun which was fermented for 7 days at room temperature. Media of MRS+CaCO3 were used to isolate the LAB while API 50 CHL kit was utilised to identify them. Fresh flowers and jaruk tigarun were also freeze-dryed, crushed and extracted using methanol, ethanol and ethyl acetate. The total phenolic and antioxidant activity of each extract were determine with Folin-Ciocalteu method and DPPH. Three isolates of LAB were isolated and identified as Lactobacillus plantarum. The fermentation was able to increase total phenolic of jaruk tigarun which was extracted with methanol, ethanol, and ethyl acetate (53.24 ± 0.73, 44.86 ± 0.90 and 23.95 ± 0.13 mg GAE/g extract, respectively. Similarly, the antioxidant activity of jaruk tigarun that were extracted with methanol, ethanol and ethyl acetate increased to 92.68 ± 0.02 %, 92.43 ± 0.11 %, and 42.94 ± 0.02 %. Methanolic extract of jaruk tigarun has the highest IC50 that was equal to 1.511 μg/mL. UV-Vis spectrum analysis and FT-IR were used to identify the compounds isolated from methanolic extract of jaruk tigarun resulting flavonoid as tentative identified compounds.   ABSTRAK Jaruk tigarun adalah salah satu makanan fermentasi tradisional dari Kalimantan Selatan yang dibuat dengan cara merendam bunga tigarun dalam air matang selama beberapa hari. Penelitian ini bertujuan untuk mengisolasi dan mengidentifikasi bakteri asam laktat yang terlibat selama fermentasi jaruk serta mengetahui aktivitas penghambatan radikal DPPH pada jaruk tigarun. BAL diisolasi dari bunga tigarun yang difermentasi selama 7 hari pada suhu kamar sampai menjadi jaruk

  17. Fatigue and retention in ferroelectric Y-Ba-Cu-O/Pb-Zr-Ti-O/Y-Ba-Cu-O heterostructures

    Science.gov (United States)

    Ramesh, R.; Chan, W. K.; Wilkens, B.; Gilchrist, H.; Sands, T.; Tarascon, J. M.; Keramidas, V. G.; Fork, D. K.; Lee, J.; Safari, A.

    1992-09-01

    Fatigue and retention characteristics of ferroelectric lead zirconate titanate thin films grown with Y-Ba-Cu-O(YBCO) thin-film top and bottom electrodes are found to be far superior to those obtained with conventional Pt top electrodes. The heterostructures reported here have been grown in situ by pulsed laser deposition on yttria-stabilized ZrO2 buffer [100] Si and on [001] LaAlO3. Both the a- and c-axis orientations of the YBCO lattice have been used as electrodes. They were prepared using suitable changes in growth conditions.

  18. Flora da Paraíba, Brasil: Combretaceae Flora of Paraíba, Brazil: Solanum L., Solanaceae

    Directory of Open Access Journals (Sweden)

    Maria Iracema Bezerra Loiola

    2009-06-01

    Full Text Available Apresenta-se o tratamento taxonômico da família Combretaceae como parte do projeto "Flora da Paraíba", que vem sendo realizado com o objetivo de identificar e catalogar as espécies da flora local. As identificações, descrições e ilustrações botânicas foram efetuadas pela análise morfológica de amostras frescas e espécimes herborizados, com o auxílio da bibliografia e análise de tipos, complementadas pelas observações de campo. Foram registradas 11 espécies subordinadas a cinco gêneros: Buchenavia (1, Combretum (8, Conocarpus (1 e Laguncularia (1. Algumas espécies possuem distribuição restrita aos manguezais, como Conocarpus erectus L. e Laguncularia racemosa (L. C.F. Gaertn., à Caatinga, como Combretum glaucocarpum Mart., C. leprosum Mart. e C. hilarianum D. Dietr., e a Floresta Atlântica, como Buchenavia tetraphylla (Aubl. R.A. Howard, Combretum fruticosum (Loefl. Stuntz e C. laxum Jacq.This taxonomic treatment of the genus Solanum is part of the "Flora da Paraíba" project which aims to identify and catalogue the species of the local flora. Botanical collections, field observations and morphological studies were done for identification, description and botanical illustration of the plant species, also supported by the literature and analysis of Brazilian and foreign herbaria, plus specimens from EAN and JPB herbaria. Twenty two species of Solanum were recorded in the state of Paraíba: Solanum agrarium Sendtn., S. americanum Mill., S. asperum Rich., S. asterophorum Mart., S. caavurana Vell., S. capsicoides All., S. crinitum Lam., S. jabrense Agra & M.Nee, S. melissarum Bohs, S. ovum-fringillae (Dunal Bohs, S. palinacanthum Dunal, S. paludosum Moric., S. paniculatum L., S. paraibanum Agra, S. polytrichum Moric., S. rhytidoandrum Sendtn., Solanum sp., S. stagnale Moric., S. stipulaceum Roem. & Schult., S. stramoniifolium Jacq., S. swartzianum Roem. & Schult. and S. torvum Sw. Three species are new records for Paraíba: S

  19. Sorghum silage production system in Cariri, Paraíba

    Directory of Open Access Journals (Sweden)

    Ebson Pereira Cândido

    2014-06-01

    Full Text Available The objective of this study was to characterize the sorghum farming and ensiling systems in the Cariri region of Paraíba State (Brazil, and to identify different groups of producers based on productive characteristics using frequency distributions, and principal component and cluster analyses. A total of 100 milk producers in the Caturité and Boqueirão municipalities in the dairy region of Cariri, Paraíba, were selected to fill out a questionnaire comprised of 32 questions to collect data on both qualitative and quantitative variables. Of the 100 properties studied, 88% cultivated sorghum as silage forage for feeding dairy cows, demonstrating the importance of this cultural practice in the region of Cariri. Statistical analyses based on the variables studied identified four groups, composed of 35, 8, 6, and 39 farmers. The sorghum cultivation and ensiling production system in Cariri can be improved through the evaluation and improvement of soil fertility to obtain higher forage production, application of weed control using herbicides, and implementation of mechanized planting and harvesting to improve efficiency and reduce costs associated with manpower.

  20. BaBar computing - From collisions to physics results

    CERN Multimedia

    CERN. Geneva

    2004-01-01

    The BaBar experiment at SLAC studies B-physics at the Upsilon(4S) resonance using the high-luminosity e+e- collider PEP-II at the Stanford Linear Accelerator Center (SLAC). Taking, processing and analyzing the very large data samples is a significant computing challenge. This presentation will describe the entire BaBar computing chain and illustrate the solutions chosen as well as their evolution with the ever higher luminosity being delivered by PEP-II. This will include data acquisition and software triggering in a high availability, low-deadtime online environment, a prompt, automated calibration pass through the data SLAC and then the full reconstruction of the data that takes place at INFN-Padova within 24 hours. Monte Carlo production takes place in a highly automated fashion in 25+ sites. The resulting real and simulated data is distributed and made available at SLAC and other computing centers. For analysis a much more sophisticated skimming pass has been introduced in the past year, ...

  1. Towards a sub 15-dBA optical micromachined microphone.

    Science.gov (United States)

    Kim, Donghwan; Hall, Neal A

    2014-05-01

    Micromachined microphones with grating-based optical-interferometric readout have been demonstrated previously. These microphones are similar in construction to bottom-inlet capacitive microelectromechanical-system (MEMS) microphones, with the exception that optoelectronic emitters and detectors are placed inside the microphone's front or back cavity. A potential advantage of optical microphones in designing for low noise level is the use of highly-perforated microphone backplates to enable low-damping and low thermal-mechanical noise levels. This work presents an experimental study of a microphone diaphragm and backplate designed for optical readout and low thermal-mechanical noise. The backplate is 1 mm × 1 mm and is fabricated in a 2-μm-thick epitaxial silicon layer of a silicon-on-insulator wafer and contains a diffraction grating with 4-μm pitch etched at the center. The presented system has a measured thermal-mechanical noise level equal to 22.6 dBA. Through measurement of the electrostatic frequency response and measured noise spectra, a device model for the microphone system is verified. The model is in-turn used to identify design paths towards MEMS microphones with sub 15-dBA noise floors.

  2. Stellar laboratories. III. New Ba v, Ba vi, and Ba vii oscillator strengths and the barium abundance in the hot white dwarfs G191-B2B and RE 0503-289

    Science.gov (United States)

    Rauch, T.; Werner, K.; Quinet, P.; Kruk, J. W.

    2014-06-01

    Context. For the spectral analysis of high-resolution and high-signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims: Reliable Ba v-vii oscillator strengths are used to identify Ba lines in the spectra of the DA-type white dwarf G191-B2B and the DO-type white dwarf RE 0503-289 and to determine their photospheric Ba abundances. Methods: We newly calculated Ba v-vii oscillator strengths to consider their radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models for the analysis of Ba lines exhibited in high-resolution and high-S/N UV observations of G191-B2B and RE 0503-289. Results: For the first time, we identified highly ionized Ba in the spectra of hot white dwarfs. We detected Ba vi and Ba vii lines in the Far Ultraviolet Spectroscopic Explorer (FUSE) spectrum of RE 0503-289. The Ba vi/Ba vii ionization equilibrium is well reproduced with the previously determined effective temperature of 70 000 K and surface gravity of log g = 7.5. The Ba abundance is 3.5 ± 0.5 × 10-4 (mass fraction, about 23 000 times the solar value). In the FUSE spectrum of G191-B2B, we identified the strongest Ba vii line (at 993.41 Å) only, and determined a Ba abundance of 4.0 ± 0.5 × 10-6 (about 265 times solar). Conclusions: Reliable measurements and calculations of atomic data are a pre-requisite for stellar-atmosphere modeling. Observed Ba vi-vii line profiles in two white dwarfs' (G191-B2B and RE 0503-289) far-ultraviolet spectra were well reproduced with our newly calculated oscillator strengths. This allowed to determine the photospheric Ba abundance of these two stars precisely. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for

  3. Thin films sputtered from Ba{sub 2}NdFeNb{sub 4}O{sub 15} multiferroic targets on BaFe{sub 12}O{sub 19} coated substrates

    Energy Technology Data Exchange (ETDEWEB)

    Bodeux, Romain [CNRS, ICMCB, UPR 9048, F-33600 Pessac (France); Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France); Michau, Dominique, E-mail: dominique.michau@icmcb.cnrs.fr [CNRS, ICMCB, UPR 9048, F-33600 Pessac (France); Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France); Maglione, Mario; Josse, Michaël [CNRS, ICMCB, UPR 9048, F-33600 Pessac (France); Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France)

    2016-09-15

    Highlights: • Synthesis of Ba{sub 2}NdFeNb{sub 4}O{sub 15}/BaFe{sub 12}O{sub 19} (BaM) heterostructures by RF magnetron sputtering. • Growth of TTB layer were retained regardless of the underlayer (Pt bottom electrode or BaM). • Dielectric and magnetic properties were obtained from the Pt/TTB/BaM/Pt stacks. - Abstract: Ba{sub 2}NdFeNb{sub 4}O{sub 15} tetragonal tungsten bronze (TTB)/BaFe{sub 12}O{sub 19} (BaM) hexaferrite bilayers have been grown by RF magnetron sputtering on Pt/TiO{sub 2}/SiO{sub 2}/Si (PtS) substrates. The BaM layer is textured along (0 0 1) while the TTB layer is multioriented regardless of the PtS or BaM/PtS substrate. Dielectric properties of TTB films are similar to those of bulk, i.e., ε ∼ 150 and a magnetic hysteresis loop is obtained from TTB/BaM bilayers, thanks to the BaM component. This demonstrates the possibility of transferring to 2 dimensional structures the composite multiferroic system TTB/BaM previously identified in 3 dimensional bulk ceramics.

  4. Identification of the neutron-rich nuclides /sup 147; 148/Ba and half- life determination of the heavy isotopes of Rb, Sr, Y, Cs, Ba and La

    CERN Document Server

    Amiel, S; Nir-El, Y; Shmid, M

    1976-01-01

    The neutron nuclides /sup 147; 148/Ba were produced in the thermal neutron induced fission of /sup 235/U. A new surface ionization integrated target ion source operating at temperatures in the region of 1800 degrees C permits the measurement of half-lives of isotopes down to about 0.1 sec due to the very fast release of atoms from the target. Isotopes of Rb, Sr, Cs, and Ba were separated by positive surface ionization and their half-lives measured using beta activity detected by a silicon surface barrier detector with a depletion depth of 300 mu . The isotopes /sup 147/Ba and /sup 148/Ba were identified for the first time and their half-lives were found to be 0.72+or-0.07 sec and 0.47+or-0.20 sec, respectively. (0 refs).

  5. Hybrid HF-DFT modeling of monolayer water adsorption on (001) surface of cubic BaHfO 3 and BaZrO 3 crystals

    Science.gov (United States)

    Bandura, A. V.; Evarestov, R. A.; Kuruch, D. D.

    2010-09-01

    First-principles calculations have been used to study the atomic structure, preferred sites and adsorption energies for water adsorption at different terminations of the cubic phase of perovskite-structured BaHfO 3 and BaZrO 3. By considering different initial positions of water molecules, the possibility of water dissociation has been investigated. It is demonstrated that the site selectivity and the form of adsorbed molecule can be affected by the choice of surface unit cell. Dissociative adsorption was found to be favorable for all surfaces in consideration. Hydroxylation of ZrO 2- and HfO 2-terminated surfaces is accomplished by a noticeable reconstruction of the surface structure of cubic phase towards the orthorhombic phase. Calculated atomic charges in bare and hydroxylated surfaces show that BaHfO 3 crystal is slightly more ionic than BaZrO 3.

  6. Molecular recognition at methyl methacrylate/n-butyl acrylate (MMA/nBA) monomer unit boundaries of phospholipids at p-MMA/nBA copolymer surfaces.

    Science.gov (United States)

    Yu, Min; Urban, Marek W; Sheng, Yinghong; Leszczynski, Jerzy

    2008-09-16

    Lipid structural features and their interactions with proteins provide a useful vehicle for further advances in membrane proteins research. To mimic one of potential lipid-protein interactions we synthesized poly(methyl methacrylate/ n-butyl acrylate) (p-MMA/nBA) colloidal particles that were stabilized by phospholipid (PLs). Upon the particle coalescence, PL stratification resulted in the formation of surface localized ionic clusters (SLICs). These entities are capable of recognizing MMA/nBA monomer interfaces along the p-MMA/nBA copolymer backbone and form crystalline SLICs at the monomer interface. By utilizing attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy and selected area electron diffraction (SAD) combined with ab initio calculations, studies were conducted that identified the origin of SLICs as well as their structural features formed on the surface of p-MMA/nBA copolymer films stabilized by 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) PL. Specific entities responsible for SLIC formation are selective noncovalent bonds of anionic phosphate and cationic quaternary ammonium segments of DLPC that interact with two neighboring carbonyl groups of nBA and MMA monomers of the p-MMA/nBA polymer backbone. To the best of our knowledge this is the first example of molecular recognition facilitated by coalescence of copolymer colloidal particles and the ability of PLs to form SLICs at the boundaries of the neighboring MMA and nBA monomer units of the p-MMA/nBA chain. The dominating noncovalent bonds responsible for the molecular recognition is a combination of H-bonding and electrostatic interactions.

  7. Investigation on microstructure and dielectric behaviour of (Ba0· 999 ...

    Indian Academy of Sciences (India)

    Ceramics of BaTiO3 co-doped with Gd and Cr at Ba-site was synthesized via solid-state reaction route. Surface morphology shows the increase in grain size with the increase of Cr-content below 3 mol%. The high value of in the synthesized samples is associated with space charge polarization and inhomogeneous ...

  8. Progress of (Sr, Ba) TiO3 ferroelectric thin film and tunability

    Indian Academy of Sciences (India)

    Unknown

    The studies on (Ba, Sr) TiO3 microstructure concentrate on the crystal structure system, grain size distribution, domain structure, layers of regions, Curie temperature, growth mechanism of grain, lattice mismatch, strain and the influence of dopants on structure and performance etc. (Sr, Ba) TiO3 crystal exists as a cube and a ...

  9. Grain-size effects on thermal properties of BaTiO3 ceramics

    Indian Academy of Sciences (India)

    Administrator

    fine non-agglomerated powder with a narrow particle size distribution and an appropriate densification method to minimize the grain growth are required. In our experi- ment, the raw BaTiO3 powder with the grain sizes of 10 and 100 nm were synthesized by chemical processing. (Li et al 2002). Dense BaTiO3 ceramics with ...

  10. Strom-Spannungs-Messungen an der BaSO4-cellophan-Membran

    NARCIS (Netherlands)

    Hirsch-Ayalon, P.

    Strom-Spannungs-Messungen sind sehr geeignet für das Studium der Permeabilität der BaSO4-Membran für Ionen. Mit verschiedenen Kombinationen von Lösungen erhält man charakteristische i/E-Linien. In geeigneter Versuchsanordnung setzt die BaSO4-Membran Konzentrations-energie (vorzugsweise von H+-

  11. BACTERICIDAL COATINGS ON TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY (BaCTeRIA) SUMMARY REPORT

    Science.gov (United States)

    2017-07-07

    TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY ( BaCTeRIA ) SUMMARY REPORT by Tobyn A. Branck Courtney M. Cowell Jennifer M. Rego and...October 2011 – September 2015 4. TITLE AND SUBTITLE BACTERICIDAL COATINGS ON TEXTILES FOR REMEDIATION OF INTERMICROBE ACTIVITY ( BaCTeRIA ) SUMMARY REPORT...ANTHRAX PURIFICATION BACILLUS ANTHRACIS ENVIRONMENTAL ISOLATES BACTERIA BACTERIOCINS TARGETED ACTIVITY

  12. Searches for low-mass Higgs and dark bosons at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Oberhof, Benjamin, E-mail: benjamin.oberhof@pi.infn.it [INFN sezione di Pisa and Universitá di Pisa, Polo Fibonacci - Edificio C, Largo B. Pontecorvo 3, 56125 - Pisa (Italy)

    2013-01-15

    We present BaBar latest results for the direct search of a light CP-odd Higgs boson using radiative decays of the ϒ(nS) (n=1,2,3) resonances in different final states. We also present the results for the search of a hidden sector gauge and Higgs bosons using the full BaBar datasample.

  13. Soft X-ray photoelectron spectroscopy of the ultrathin Ba/InGaN interface

    Science.gov (United States)

    Benemanskaya, G. V.; Pronin, V. P.; Timoshnev, S. N.; Nelyubov, A. V.

    2017-11-01

    Electronic structure of the clean In0.22Ga0.78N surface and the ultrathin Ba/In0.22Ga0.78N interface has been studied in situ by the synchrotron-based photoelectron spectroscopy during excitation in the photon energy range of 100-650 eV. Changes in the valence band and surface states spectra and in the In 3d, In 4d, N 1s, Ga 3d, Ba 4d, Ba 5p core levels spectra have been investigated under the step-by-step Ba submonolayer deposition. Changes in the surface electronic structure of the InGaN caused by Ba adsorption are found to originate predominantly from the local interaction of the Ga and In dangling bonds and Ba adatoms that results in effect of the suppression of the two intrinsic surface states and appearance of a new induced state. The Ba atomic layer deposition is revealed to induce the charge transfer between the Ba adatoms and the N surface atoms with increasing N-ionicity.

  14. Ba/ZrO₂ nanoparticles as efficient heterogeneous base catalyst for ...

    Indian Academy of Sciences (India)

    The surface area, basicity and barium content of the material depend strongly on the method of synthesis. The Ba/ZrO₂ catalyst prepared by urea hydrolysis method exhibited higher surface area and barium content compared to other samples. The catalytic activity of the Ba/ZrO₂ catalyst was evaluated for synthesis of ...

  15. The Acquisition of the BA Construction by English-Speaking Learners of Chinese

    Science.gov (United States)

    Xu, Hongying

    2012-01-01

    This study examined the acquisition of the BA construction by English-speaking learners of Chinese. The BA construction is a unique yet important grammar phenomenon in Chinese. Whether second language (L2) learners of Chinese are able to understand and use this construction correctly and appropriately may affect the overall success of their…

  16. Reversible Decomposition of Secondary Phases in BaO Infiltrated LSM Electrodes-Polarization Effects

    DEFF Research Database (Denmark)

    Traulsen, Marie Lund; McIntyre, Melissa D.; Norrman, Kion

    2016-01-01

    potential. A changing electrode surface is observed during operation as the Ba3Mn2O8 secondary phase decomposes and manganese oxide accumulates on the electrode surface during cathodic polarization. The observed changes are reversible. These results suggest that the formation of Ba3Mn2O8 is responsible...

  17. Microstructure and electrical properties of BaTiO3 thin films by modified CSD

    National Research Council Canada - National Science Library

    NAGASAKA, Masaomi; IWASAKI, Dai; SAKAMOTO, Naonori; FU, Desheng; WAKIYA, Naoki; SUZUKI, Hisao

    2011-01-01

    0.3 M BaTiO3 (BT) precursor solution was prepared by the modified CSD, in which partially hydrolyzed Ti-alkoxide and Ba precursor solution was reacted in iced water bath to prepare the highly polymerized BT precursor solution...

  18. Mixed marriages in Ba's so long a letter and scarlet song | Simon ...

    African Journals Online (AJOL)

    Love is the prerequisite for marriage in all cultures. This fact is negated in the marriage relationships described in Ba's two works. This paper examines mixed marriages in Mariama Ba's So Long a Letter and Scarlet Song and its impact on women. It also highlights the woman's predicament in general and the way forward ...

  19. Electrodeposition of BaCO3 coatings on stainless steel substrates ...

    Indian Academy of Sciences (India)

    Administrator

    Department of Chemistry, Central College, Bangalore University, Bangalore 560 001. 2 ... and dissolved ions that can influence the process. Therefore many ... and paper industries. Also it is used as starting mate- rial for BaTiO3 synthesis. Decomposition of a bi- phasic coating of BaCO3 and TiO2 resulted in the formation of ...

  20. Anomalous properties of chloroborosilicate glasses in the K2O–BaO ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 38; Issue 6. Anomalous properties ... All of the thermal and mechanical properties exhibited a similar trend of anomalous variation as a function of the BaCl2 content, showing maxima at 10 mol% and a sharp increase at 25 mol% BaCl2 content. The anomaly has been ...

  1. First-principles study of the relaxor ferroelectricity of Ba(Zr, Ti)O3

    Science.gov (United States)

    Yang, Li-Juan; Wu, Ling-Zhi; Dong, Shuai

    2015-12-01

    Ba(Zr, Ti)O3 is a lead-free relaxor ferroelectric. Using the first-principles method, the ferroelectric dipole moments for pure BaTiO3 and Ba(Zr, Ti)O3 supercells are studied. All possible ion configurations of BaZr0.5Ti0.5O3 and BaZr0.25Ti0.75O3 are constructed in a 2 × 2 × 2 supercell. For the half-substituted case, divergence of ferroelectric properties is found from these structures, which greatly depends on the arrangements of Ti and Zr ions. Thus our results provide a reasonable explanation to the relaxor behavior of Ba(Zr, Ti)O3. In addition, a model based on the thermal statistics gives the averaged polarization for Ba(Zr, Ti)O3, which depends on the temperature of synthesis. Our result is helpful to understand and tune the relaxor ferroelectricity of lead-free Ba(Zr, Ti)O3. Project supported by the National Natural Science Foundation of China (Grant Nos. 51322206 and 11274060) and the Natural Science Foundation of Jiangsu Province, China (Grant No. 15KJB140009).

  2. Dy -activated M2SiO4 (M = Ba, Mg, Sr)-type phosphors

    Indian Academy of Sciences (India)

    aging, photoluminescence (PL) and microwave communica- tion areas due to their high efficiency, easy synthesis method and plenty of host materials [1–3]. ... decomposition of BaCO3, which changes into BaO, from figure 1, an orthorhombic to rhombohedral transition at. 823. ◦. C and a rhombohedral to cubic phase ...

  3. Characterization of BaTiO3 piezoelectric perovskite material for ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 40; Issue 4. Characterization of BaTiO 3 piezoelectric perovskite material ... In this study, we present the results of the manufacturing of BaTiO 3 powder, which is meant for use in stacked-diskmultilayer actuator production. The solid-state technique was used for powder ...

  4. Tsdc and Neutron-Scattering Measurements on Ba1-Xlaxf2+X and Ba1-Xuxf2+2x Solid-Solutions

    DEFF Research Database (Denmark)

    Ouwerkerk, M; Veldkamp, F. F.; Andersen, Niels Hessel

    1985-01-01

    A study was made of the dynamical behaviour of bound interstitial fluoride ions in disordered Ba1−xLaxF2+x and Ba1−xUxF2+2x solid solutions with Thermally Stimulated Depolarisation Current measurements and neutron scattering measurements, and a combination of both techniques. From 10 K to 400 K...... the TSDC spectra showed four reorientation peaks to be present in Ba1−xLaxF2+x, and six in Ba1−xUxF2+2x, along with the relaxation of the macroscopic space charge. The position of a space charge peak shifted to lower temperatures with increasing solute content. The dipolar realaxations were concentration...... invariant. In Ba1−xLaxF2+x neutral associates, L-shaped- and (222)- clusters occur. The present study reveals (212)-clusters to be present in Ba1−xUxF2+2x. The relations between ion dynamics and defect structures are discussed....

  5. Understanding Ferromagnetic Phase Stability, Electronic and Transport Properties of BaPaO3 and BaNpO3 from Ab-Initio Calculations

    Science.gov (United States)

    Khandy, Shakeel Ahmad; Gupta, Dinesh C.

    2017-10-01

    An extensive study of rare-earth perovskite BaPaO3 and BaNpO3 has been performed by first-principles tactics based on density functional theory (DFT), because the delocalized f-electrons play an important role in the band structure formation, to reveal their impact on the overall physical and chemical properties; it has turned out to be an interesting theme. Along with critical radii and thermoelectric properties, two different theories are employed to calculate the structural properties. The DFT and empirically calculated lattice constants are in rational accord with the experimental results. The critical radius calculations show that the BaPaO3 lattice has a smaller oxygen migration activation energy than the BaNpO3. In addition, we discuss the band profile and magnetic moments for these materials, which demonstrate the half-metallic ferromagnetism with a direct energy gap of 3.91 eV for BaPaO3 and an indirect gap of 3.79 eV for BaNpO3. More interestingly, the integral magnetic moments are in accordance with the Slater-Pauling rule.

  6. BA- proposal made in collaboration between students and clinical practitioner at the OT-program

    DEFF Research Database (Denmark)

    Hove, Anne

    2014-01-01

    Presentation 24 BA- proposal made in collaboration between students and clinical practitioner at the OT-program Anne Hove (Metropolitan University College, Denmark) At the OT education a key aim is to ensure the students develop their BA-projects in a concrete collaboration with the practice field...... developing a project proposal is a difficult task. We have therefore in the spring of 2014 piloted a new ways of addressing this challenge. We have given students and practitioners the opportunity to develop project proposals in collaboration. I will present the first experiences from the pilot. We will host....... This focus is strengthen through a process where clinical practitioners and students develop in collaboration project proposals to BA-projects. We strongly believe that students learn more with this type of BA-project. In the lecture, I will short describe the learning potential we see in this type of BA...

  7. Bifunctional properties of hydrothermal synthesized BaMF4 (M = Co, Ni and Zn

    Directory of Open Access Journals (Sweden)

    Farheen N. Sayed

    2013-07-01

    Full Text Available BaMF4 (M = Co, Ni and Zn samples having orthorhombic structure have been synthesized by a mild hydrothermal method and characterized by x-ray diffraction (XRD, magnetic and electrical measurements. Single phase formation of these compounds has been found to be dependent on various factors like reaction time, pH, temperature etc. All the samples showed ferroelectricity, which decreases with increase in temperature. BaMF4 (M = Co, Ni samples show 10-15 times more leakage current compared to that of BaZnF4 at higher applied field. Absence of multivalent ions in BaZnF4 can be the reason for its minimum leakage current. All the samples except, BaZnF4, exhibit weak room temperature ferromagnetism also.

  8. Historical materials from the medieval fortress Bač

    Directory of Open Access Journals (Sweden)

    Snežana Petrović

    2007-12-01

    Full Text Available Conservation and restoration of cultural heritage are the objects of great interest worldwide. For setting the correct methodology for the procedures of the restoration it is very important to have the right information about the state of the object and the characteristics of the original materials. The basis of our examinations were clay products (samples of bricks, terracotta and clay roof tile from the middle ages, the fortress in Bač. The following methods were used: x-ray diffraction, classic chemical analysis, SEM-EDS, Hg-porosimetry and dilatometry. Based on the used methods, mineral composition, temperature and regime of firing and textural properties of the examined materials were determined. The degree of destruction of examined materials was also identified, in order to find compatible materials for future techniques of conservation and restoration.

  9. Complex Impedance Spectroscopic Properties of BaVO Ceramics

    Directory of Open Access Journals (Sweden)

    Praveen Khatri

    2008-01-01

    Full Text Available The polycrystalline sample of Ba3V2O8 was prepared by a high-temperature solid-state reaction technique. The effect of temperature on impedance parameters was studied using an impedance analyzer in a wide frequency range (102-106 Hz. The real and imaginary parts of complex impedance trace semicircles in the complex plane. The temperature-dependent plots reveal the presence of both bulk and grain boundary effects above 125∘C. The bulk resistance of the material decreases with rise in temperature. This exhibits a typical negative temperature coefficient of resistance (NTCR behavior of the material. The modulus analysis suggests a possible hopping mechanism for electrical transport processes of the material. The nature of variation of dc conductivity suggests the Arrhenius type of electrical conductivity.

  10. The New BaBar Data Reconstruction Control System

    Energy Technology Data Exchange (ETDEWEB)

    Ceseracciu, Antonio

    2003-06-02

    The BaBar experiment is characterized by extremely high luminosity, a complex detector, and a huge data volume, with increasing requirements each year. To fulfill these requirements a new control system has been designed and developed for the offline data reconstruction system. The new control system described in this paper provides the performance and flexibility needed to manage a large number of small computing farms, and takes full benefit of OO design. The infrastructure is well isolated from the processing layer, it is generic and flexible, based on a light framework providing message passing and cooperative multitasking. The system is actively distributed, enforces the separation between different processing tiers by using different naming domains, and glues them together by dedicated brokers. It provides a powerful Finite State Machine framework to describe custom processing models in a simple regular language. This paper describes this new control system, currently in use at SLAC and Padova on {approx}450 CPUs organized in 12 farms.

  11. The magnetic properties of multiferroic BaCoF4

    Directory of Open Access Journals (Sweden)

    Shuang Zhou

    2017-05-01

    Full Text Available Multiferroic barium cobalt fluoride, BaCoF4, has been prepared by hydrothermal method. The antiferromagnetic structure has been confirmed, and the possible weak ferromagnetism due to Dzyaloshinskii-Moriya interaction has been excluded, from the straight line shape of applied magnetic field dependent magnetization (M-H curve without hysteresis loop at low temperature down to 5 K. After cooling under a magnetic field, conspicuous exchange bias effect was observed at low temperature of T<50 K, which was attributed to the exchange coupling between the two phases of different spin configuration. Furthermore, significant magnetodielectric effect was observed at room temperature, which has been interpreted to the magnetic field modified weak interaction between different layers.

  12. Aluminosilicates compacts by alkoxide route: influence of Ba addition

    Directory of Open Access Journals (Sweden)

    Quaranta N. E.

    1999-01-01

    Full Text Available The sol-gel route was employed to obtain three different powders with the stoichiometric composition corresponding to mullite (3 Al2O3.2SiO2: (i commercial alumina and silica from sol-gel, (ii alumina and silica by alkoxide partial hydrolysis, (iii alumina and silica by alkoxide simultaneous hydrolysis. Tetraethylorthosilicate (TEOS and aluminium tri-sec-butoxide were used as alkoxide precursor. Moreover, 5 wt% of barium, incorporated to precursor solutions as Ba-acetilacetonate, was used as additive to study its influence on densification and mullite phase formation. The precursor powders were pressed uniaxially to form green compacts, after that all samples were heated to 1350 °C for 2 hours to obtain densified pellets. X-ray diffration patterns of powders, obtained by milling of sintering compacts, showed important differences. In barium doped samples a higher grade of densification and a greater glassy phase formation were observed.

  13. Chain magnetic polarons in Y-Ba-Cu-O

    CERN Document Server

    Eremenko, V V; Ponomarchuk, V L

    2002-01-01

    The electron self-localization process in a superconducting cuprate paramagnetic compound Y-Ba-Cu-O is studied by the Moessbauer effect technique. It is shown that the electron self-localization in chain sites gives rise to a phase with a local magnetic ordering and a relaxation time more than 10 sup - sup 7 s. Analysis of the accompanying charge redistribution suggests that the electron self-localization creates a pair of exchange interacted electrons which are mainly localized in oxygen sites. Such a quasiparticle, which consists of a pair of antiferromagnetically oriented atomic moments and a pair of self-localized electrons, has an integer spin and may form a Bose-condensate.

  14. Radiation dosimetry using nano-BaSO{sub 4}:Eu

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, A.; Sharma R, K. [University of Delhi, Department of Physics, Sri Venkateswara College, Benito Juarez Road, Dhaula Kuan, 110021 New Delhi (India); Bahl, S.; Kumar, P. [Medical Physics Unit, IRCH, AIIMS, 110029 New Delhi (India); Pal L, S., E-mail: apandey@svc.ac.in [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, 110067 New Delhi (India)

    2015-10-15

    Nanocrystalline barium sulfate doped with europium (BaSO{sub 4}:Eu) was successfully prepared by the chemical co-precipitation technique and its thermoluminescence (Tl) dosimetry characteristics were studied for gamma radiation. Initially the dopant (Eu) concentration was varied, starting from 0.05 mol % to up to 1.00 mol %, and it was found that the nano phosphor BaSO{sub 4}:Eu with the dopant concentration of 0.2 mol % had the highest sensitivity within the given lot. The nano phosphor was also optimized for its annealing temperature in order to obtain the best results and was thereafter tested for its reusability and fading features. Further the nano phosphor was compared with the commercially available standard Tl dosimeter material LiF:Mg,Ti (popularly referred to as TLD-100) and it was found that the nano phosphor not only had a higher Tl sensitivity compared to the standard material over a wide range of doses but also had a Tl response which was linear even beyond the dose of 1 kGy. Linearity in Tl response to up to such high doses (∼1 kGy) is typical of nanocrystalline Tl phosphors. All the samples were irradiated by Co-60 source (having 1.25 MeV average energy) of gamma radiation. In order to test the energy independence of the nano phosphor (an important characteristic of an ideal Tl dosimeter) further studies are being carried out to examine the response of the nano phosphor to ionizing radiations of different energies. (Author)

  15. Virus, bakterier og toksiner som biologiske kampstoffer

    DEFF Research Database (Denmark)

    Hansen, J E

    1999-01-01

    Biological weapons are an important part of the level of international threat. Technological development has made biological weapon production relatively simple and cheap, and although a UN convention from 1972 bans biological weapons, governments as well as non-governmental organisations...... or individuals have developed biological weapons for offensive use in war or terrorism. This article reviews the publically available literature, and clinical and therapeutic possibilities are described. The possibilities for protection of military and civilian groups are discussed and the need for a national...

  16. Selektion og spredning af antibiotikaresistente bakterier

    DEFF Research Database (Denmark)

    Kolmos, Hans Jørn Jepsen; Frimodt-møller, Niels

    2011-01-01

    and disinfectants. Therefore, abundant use of metals, e.g. copper and zinc for growth promotion in animals used for food, may also co-select for antibiotic resistance. The same applies to disinfectants, e.g. silver and chlorhexidine. Prudent use of antibiotics and these other agents is essential to control......Use of an antibiotic may not only select for resistance against the agent itself, but may at the same time co-select for resistance against other antibiotics if resistance genes are linked on e.g. a plasmid. Resistance plasmids may also carry genes mediating resistance against metals...... antibiotic resistance....

  17. Conjunctivitis Bakterial Treatment in Kota Karang Village

    OpenAIRE

    Ramadhanisa, Aqsha

    2014-01-01

    Conjunctivitis is an eye disease that can occur in adults and children. The incident of conjungtivitis in Indonesia currently occupies the second place of 10 major eye disease. In the treatment of disease, the approach in medical care not only focuses on the biological aspect (disease) but also influence by phisicosocial aspect. Because of the interaction between social communities and families with the help of the community environment is helpful not only in solving clinical problem but also...

  18. Selektion og spredning af antibiotikaresistente bakterier

    DEFF Research Database (Denmark)

    Frimodt-Møller, Niels; Kolmos, Hans Jørn

    2011-01-01

    and disinfectants. Therefore, abundant use of metals, e.g. copper and zinc for growth promotion in animals used for food, may also co-select for antibiotic resistance. The same applies to disinfectants, e.g. silver and chlorhexidine. Prudent use of antibiotics and these other agents is essential to control...

  19. Synthesis, Crystal Structure, and Chemical-Bonding Analysis of BaZn(NCN2

    Directory of Open Access Journals (Sweden)

    Alex J. Corkett

    2017-12-01

    Full Text Available The ternary carbodiimide BaZn(NCN2 was prepared by a solid-state metathesis reaction between BaF2, ZnF2, and Li2NCN in a 1:1:2 molar ratio, and its crystal structure was determined from Rietveld refinement of X-ray data. BaZn(NCN2 represents the aristotype of the LiBa2Al(NCN4 structure which is unique to carbodiimide/cyanamide chemistry and is well regarded as being constructed from ZnN4 tetrahedra, sharing edges and vertices through NCN2− units to form corrugated layers with Ba2+ in the interlayer voids. Structural anomalies in the shape of the cyanamide units are addressed via IR spectrometry and DFT calculations, which suggest the presence of slightly bent N=C=N2− carbodiimide units with C2v symmetry. Moreover, chemical-bonding analysis within the framework of crystal orbital Hamilton population (COHP reveals striking similarities between the bonding interactions in BaZn(NCN2 and SrZn(NCN2 despite their contrasting crystal structures. BaZn(NCN2 is only the second example of a ternary post-transition metal carbodiimide, and its realization paves the way for the preparation of analogues featuring divalent transition metals at the tetrahedral Zn2+ site.

  20. Dynamics of photoexcited Ba{sup +} cations in {sup 4}He nanodroplets

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Antonio; Pi, Martí [Departament ECM, Facultat de Física, and IN" 2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain); Zhang, Xiaohang; Drabbels, Marcel [Laboratoire de Chimie Physique Moléculaire, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Barranco, Manuel [Departament ECM, Facultat de Física, and IN" 2UB, Universitat de Barcelona, Diagonal 645, 08028 Barcelona (Spain); Laboratoire des Collisions, Agrégats, Réactivité, IRSAMC, UMR 5589, CNRS et Université Paul Sabatier-Toulouse 3, 118 route de Narbonne, F-31062 Toulouse Cedex 09 (France); Cargnoni, Fausto [Istituto di Scienze e Tecnologie Molecolari (ISTM), Consiglio Nazionale delle Ricerche, via Golgi 19, 20133 Milano (Italy); Hernando, Alberto [Social Thermodynamics Applied Research (SThAR), EPFL Innovation Park, Bâtiment C, CH-1015 Lausanne (Switzerland); Mateo, David [Department of Chemistry and Biochemistry, California State University at Northridge, Northridge, California 91330 (United States); Mella, Massimo [Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell’Insubria, via Valleggio 11, 22100 Como (Italy)

    2016-03-07

    We present a joint experimental and theoretical study on the desolvation of Ba{sup +} cations in {sup 4}He nanodroplets excited via the 6p ← 6s transition. The experiments reveal an efficient desolvation process yielding mainly bare Ba{sup +} cations and Ba{sup +}He{sub n} exciplexes with n = 1 and 2. The speed distributions of the ions are well described by Maxwell-Boltzmann distributions with temperatures ranging from 60 to 178 K depending on the excitation frequency and Ba{sup +} He{sub n} exciplex size. These results have been analyzed by calculations based on a time-dependent density functional description for the helium droplet combined with classical dynamics for the Ba{sup +}. In agreement with experiment, the calculations reveal the dynamical formation of exciplexes following excitation of the Ba{sup +} cation. In contrast to experimental observation, the calculations do not reveal desolvation of excited Ba{sup +} cations or exciplexes, even when relaxation pathways to lower lying states are included.

  1. Phase controlled synthesis of (Mg, Ca, Ba)-ferrite magnetic nanoparticles with high uniformity

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.F., E-mail: wangshifa2006@yeah.net [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan (China); Science and technology on vacuum technology and physics laboratory, Lanzhou Institute of Physics, Lanzhou 730000, Gansu (China); Li, Q. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan (China); Zu, X.T., E-mail: xtzu@uestc.edu.cn [Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan (China); Xiang, X.; Liu, W. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan (China); Li, S., E-mail: sean.li@unsw.edu.au [School of Material Science and Engineering, University of New South Wales, Sydney 2052 (Australia)

    2016-12-01

    (Mg, Ca, Ba)-ferrite magnetic nanoparticles were successfully synthesized through modifying the atomic ratio of polysaccharide and chelating agent at an optimal sintering temperature. In the process, the polysaccharide plays an important role in drastically shrinking the precursor during the gel drying process. In the metal-complex structure, M{sup 2+} ion active sites were coordinated by −OH of the water molecules except for EDTA anions. The MFe{sub 2}O{sub 4} magnetic nanoparticles exhibited enhanced magnetic properties when compared with nano-MFe{sub 2}O{sub 4} of similar particle size synthesized by other synthesis route reported in the literature. In particular, the sintering temperature improves the crystallinity and increases the hysteresis loop squareness ratio of (Mg, Ca, Ba)-ferrite nanoparticles significantly. - Graphical abstract: Schematic representation of the proposed model for MFe{sub 2}O{sub 4} nanoparticle synthesis, starting from EDTA-chelated M{sup 2+} (M=Mg, Ca, or Ba) cations (left). High dispersion (Mg, Ca, Ba)-ferrite magnetic nanoparticles were prepared by a modified polyacrylamide gel route. Optimized utilization of polysaccharide, chelating agent, and sintering temperature allowed the formation of (Mg, Ca, Ba)-ferrite nanoparticles with a narrow diameter distribution. - Highlights: • We report a modified polyacrylamide gel route to synthesize (Mg, Ca, Ba)-ferrite magnetic nanoparticles. • Chelate mechanism of metal ions (Mg, Ca, Ba) and EDTA has been discussed. • Phase transformation process of (Mg, Ca, Ba)-ferrites has been discussed. • The preparation method increases the hysteresis loop squareness ratio of (Mg, Ca, Ba)-ferrite nanoparticles.

  2. Rapid preparation of ultrafine BaSO{sub 3} by SO{sub 2} storage material

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fei; Sha, Feng; Qiao, Xian Shu; Zhao, Tian Xiang; Guo, Bo; Zhang, Jian Bin [College of Chemical Engineering, Inner Mongolia University of Technology, Huhhot (Korea, Republic of)

    2017-01-15

    In this work, a green and efficient process was developed for the preparation of ultrafine BaSO{sub 3} with layered nanostructure surface via the reaction of BaCl{sub 2} with a SO{sub 2} storage material (SO{sub 2}SM) at room temperature. The absorption of SO{sub 2} with equimolar ethylenediamine (EDA) and ethylene glycol (EG) afforded SO{sub 2}SM, which not only offered alkyl sulfite but also released EDA and EG that served as efficient surfactants to promote the formation of BaSO{sub 3} with spherical morphology and porous structure in the process of synthesis of ultrafine BaSO{sub 3}. The factors affecting the morphology and size of BaSO{sub 3} particle were assessed by investigating the effects of SO{sub 2}SM concentration, BaCl{sub 2} concentration, stirring time and speed. It was found that a higher SO{sub 2}SM concentration led to a higher degree of supersaturation, and the particle size of BaSO{sub 3} could be reduced by increasing SO{sub 2}SM concentration. Moreover, under the identified optimal reaction conditions, ultrafine BaSO{sub 3} was obtained with an average diameter of 450 nm. In addition, a plausible formation process of BaSO{sub 3} was proposed to explain the observed reaction results. Overall, the developed process in this work provides an efficient method for the capture, utilization, and conversion of SO{sub 2} into a valuable chemical.

  3. Bağırsak Mikrobiyatası, Probiyotikler ve İrritable Bağırsak Sendromu(İBS)

    OpenAIRE

    Karacaer, Cengiz; Varım, Ceyhun; Toka, Bilal; Yaylacı, Selçuk; Ahmet Bilal GENÇ

    2017-01-01

    İrritable bağırsak sendromu (İBS), karın ağrısı, rahatsızlıkhissi ve bağırsakalışkanlıklarının değişmesi gibi belirtilerle karakterizekompleks bir hastalıktır.Son deneysel ve klinik araştırmalara dayanarak, düşükdereceli inflamasyon, değiştirilmiş bağırsak mikrobiyatası ve bağırsakbağışıklık sistemindeki değişikliği içermektedir.Bu etiyolojik faktörlerin İBSpatogenezinde önemli rol oynadığı öne sürülmüştür.Bunedenle, değişmiş bağırsak mikrobiyotiklerinin terapötik restorasyonu İBS içinideal b...

  4. Low-energy oxygen ion beam assisted growth of BaO/EuBa2Cu3O7-δ multilayers in ultrahigh vacuum

    Science.gov (United States)

    Pindoria, Govind; Kawaguchi, K.; Morishita, Tadataka

    1996-07-01

    Molecular beam epitaxial growth of cuprate oxide superconducting thin films using a mass separated, low energy, O+ beam source, is discussed. The mono-valent O+ ion is chemically, highly reactive, and its kinetic energy at 10's of electron volts, is significant. It allows the growth of REBa2Cu3O7-(delta ) (REBCO) thin films at low pressures and temperatures. The effective over-pressure of the O+ ions at the substrate being 2 X 10-7 Torr, and the optimum growth temperature 500 degrees C. These conditions are below the currently accepted stability line for the growth of REBCO thin films. We characterize the physical and chemical properties of the O+ ion beam, and its effect on superconducting thin films. We have grown highly crystalline BaO and EuBa2Cu3O7-(delta ) (EBCO) thin films on SrTiO3 substrates. The full width at half maximum of the rocking curves for BaO(002) equals 0.07 degrees and that for the EBCO (005) peak equals 0.05 degrees. Also, we found that BaO is a good insulating material (1.7 X 1013 (Omega) m at 4K), with an excellent lattice match to EBCO, therefore a suitable candidate as an insulating layer in multilayer structures. The results of the first growth studies of BaO/EBCO multilayers are discussed.

  5. Genomics-based high-resolution mapping of the BaMMV/BaYMV resistance gene rym11 in barley (Hordeum vulgare L.).

    Science.gov (United States)

    Lüpken, Thomas; Stein, Nils; Perovic, Dragan; Habekuss, Antje; Krämer, Ilona; Hähnel, Urs; Steuernagel, Burkhard; Scholz, Uwe; Zhou, Rounan; Ariyadasa, Ruvini; Taudien, Stefan; Platzer, Matthias; Martis, Mihaela; Mayer, Klaus; Friedt, Wolfgang; Ordon, Frank

    2013-05-01

    Soil-borne barley yellow mosaic virus disease, caused by different strains of Barley yellow mosaic virus (BaYMV) and Barley mild mosaic virus (BaMMV), is one of the most important diseases of winter barley (Hordeum vulgare L.) in Europe and East Asia. The recessive resistance gene rym11 located in the centromeric region of chromosome 4HL is effective against all so far known strains of BaMMV and BaYMV in Germany. In order to isolate this gene, a high-resolution mapping population (10,204 meiotic events) has been constructed. F2 plants were screened with co-dominant flanking markers and segmental recombinant inbred lines (RILs) were tested for resistance to BaMMV under growth chamber and field conditions. Tightly linked markers were developed by exploiting (1) publicly available barley EST sequences, (2) employing barley synteny to rice, Brachypodium distachyon and sorghum and (3) using next-generation sequencing data of barley. Using this approach, the genetic interval was efficiently narrowed down from the initial 10.72 % recombination to 0.074 % recombination. A marker co-segregating with rym11 was developed providing the basis for gene isolation and efficient marker-assisted selection.

  6. Relationship between Ba atom emission and electrode temperature in a low-pressure fluorescent lamp

    Energy Technology Data Exchange (ETDEWEB)

    Yamagata, Yukihiko, E-mail: yamagata@ence.kyushu-u.ac.j [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasugakouen, Kasuga, Fukuoka 816-8580 (Japan); Kai, Makoto [Lighting Company, Panasonic Corporation, 1-1 Saiwaicho, Takatsuki, Osaka 569-1193 (Japan); Naito, Sho; Tomita, Kentaro; Uchino, Kiichiro [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasugakouen, Kasuga, Fukuoka 816-8580 (Japan); Manabe, Yoshio [Lighting Company, Panasonic Corporation, 1-1 Saiwaicho, Takatsuki, Osaka 569-1193 (Japan)

    2010-04-30

    A relationship between emission characteristics of Ba atom as an emitter material and temperature distributions of an electrode in a fluorescent lamp is described, which is measured by using laser-induced fluorescence and black-body radiation method, respectively. In a virgin lamp, a hot spot observed at the electrode edge connected to the power supply is the main source of Ba atom emission. In a long-term-used lamp, it is shown that Ba atom emission, thermionic electron emission in cathode half-cycle and electron collection in anode half-cycle are most active on the hot spot appearing on the center of the electrode.

  7. Melatonin ve Bağışıklık Sistemi

    OpenAIRE

    ÇETİN, E.

    2005-01-01

    Melatonin, pineal bezin beta adrenerjik reseptörlerinin aktivasyonu ile triptofandan sentezlenen bir hormondur.Üretim ve salınımı karanlık ile başlar ve aydınlıkla sona erer. Melatonin, birçok biyolojik fonksiyonun düzenlenmesinderol oynar. Bu derlemede melatonin hakkında genel bilgiler verilerek, melatoninin lenfoid dokular, humoral bağışıklık,hücresel bağışıklık ve kanser üzerine etkileri tartışılmıştır

  8. Metrological activity determination of {sup 133}Ba by sum-peak absolute method

    Energy Technology Data Exchange (ETDEWEB)

    Silva, R.L. da; Delgado, J.U.; Poledna, R.; Santos, A.; Veras, E.V. de; Rangel, J.; Trindade, O.L. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Almeida, M.C.M. de, E-mail: marcandida@yahoo.com.br, E-mail: candida@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The National Laboratory for Metrology of Ionizing Radiation provides gamma sources of radionuclide and standardized in activity with reduced uncertainties. Relative methods require standards to determine the sample activity while the absolute methods, as sum-peak, not. The activity is obtained directly with good accuracy and low uncertainties. {sup 133}Ba is used in research laboratories and on calibration of detectors for analysis in different work areas. Classical absolute methods do not calibrate {sup 133}Ba due to its complex decay scheme. The sum-peak method using gamma spectrometry with germanium detector standardizes {sup 133}Ba samples. Uncertainties lower than 1% to activity results were obtained.

  9. Phonon modes in Gd1-xCexBa2Cu3O7-δ

    Directory of Open Access Journals (Sweden)

    SH Mozaffari

    2009-08-01

    Full Text Available  XRD and Raman analyses were performed to probe the phase formation and the variation of the normal phonon frequencies of the high temperature superconductor GdBa2Cu3O7-δ upon Ce doping. It was found that in addition to the orthorhombic 123 phase, some nonsuperconducting peaks, which are mainly due to the BaCeO3 secondary phase, are also formed that suppress the superconducting transition temperature. Besides, analysis of the Raman peaks shows that substitutions of Ce for Gd in GdBa2Cu3O7-δ are restricted to low concentrations in favor of impurity island formation .

  10. Solution based approaches for the morphology control of BaTiO3 particulates

    OpenAIRE

    Florentina Maxim; Paula Ferreira; Paula M. Vilarinho; Ian Reaney; Anne Aimable; Paul Bowen

    2010-01-01

    Within the action COST 539 - ELENA our contribution was aimed at studying solution based approaches for the morphology control of BaTiO3 particulates. Initially, our kinetic analysis and systematic structural and morphological studies, demonstrated that during hydrothermal synthesis from layered titanate nanotubes (TiNTS), BaTiO3 forms via two mechanisms depending on the temperature and time. At low temperatures (90°C), “wild” type BaTiO3 dendritic particles with cubic structure were formed t...

  11. Preparation and Stoichiometry Effects on Microstructure and Properties of High Purity BaTiO3.

    Science.gov (United States)

    1986-03-27

    established calcined powders. Hydrothermal synthesis of polycrystalline BaTIO 3 involves dissolution of barium hydroxide and titanium dioxide in a...thermal decomposition of oxalates and by hydrothermal synthesis . As-received lots of mixed oxide and oxalate-derived powders had Ba:TI ratios of 0.997 and...BaTiO 3," Bull. Am. Ceram. Soc., 60 [5] 566-70 (1981). 10. L. I Shvets, N. A. Ovramenko and F. 0. Qvramenko, " Hydrothermal Synthesis of Highly-Dispersed

  12. Microstructural properties of BaTiO{sub 3} ceramics and thin films

    Energy Technology Data Exchange (ETDEWEB)

    Fundora C, A.; Portelles, J.J.; Siqueiros, J.M. [Posgrado en Fisica de Materiales, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada. Apartado Postal 2861, 22800 Ensenada, Baja California (Mexico)

    2000-07-01

    A microstructural study of BaTiO{sub 3} ceramics obtained by the conventional ceramic method is presented. Targets were produced to grow BaTiO{sub 3} thin films by pulsed laser deposition on Pt/Ti/Si (100) substrates. X-ray diffraction, Auger Electron Spectroscopy, X-ray Photon Spectroscopy and Scanning Electron Microscopy were used to study the properties of the BaTiO{sub 3} ceramic samples and thin films, as deposited and after an annealing process. (Author)

  13. Addendum: Safety Standards for Gua sha (press-stroking) and Ba guan (cupping).

    Science.gov (United States)

    Nielsen, Arya; Kligler, Ben; Koll, Brian S

    2014-06-01

    Our previous article Safety Standards for Gua sha (press-stroking) and Baguan (cupping) discussed the risk of transfer of blood-borne pathogens with Gua sha and Ba guan, identified Gua sha and Ba guan 'instrument criticality' as semi-critical and offered recommendations for safe practice based on hospital disinfection standards. Based on the article's feedback, we feel the need to clarify that Gua sha and Ba guan instruments, if intended for reuse, must undergo high level disinfection (HLD) or, in the case of 'wet-cupping', sterilization. We update our recommendations to be amenable to both private practice and education settings. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Barium isotope fractionation during experimental formation of the double carbonate BaMn[CO3](2) at ambient temperature.

    Science.gov (United States)

    Böttcher, Michael E; Geprägs, Patrizia; Neubert, Nadja; von Allmen, Katja; Pretet, Chloé; Samankassou, Elias; Nägler, Thomas F

    2012-09-01

    In this study, we present the first experimental results for stable barium (Ba) isotope ((137)Ba/(134)Ba) fractionation during low-temperature formation of the anhydrous double carbonate BaMn[CO(3)](2). This investigation is part of an ongoing work on Ba fractionation in the natural barium cycle. Precipitation at a temperature of 21±1°C leads to an enrichment of the lighter Ba isotope described by an enrichment factor of-0.11±0.06‰ in the double carbonate than in an aqueous barium-manganese(II) chloride/sodium bicarbonate solution, which is within the range of previous reports for synthetic pure BaCO (3) (witherite) formation.

  15. Critical currents and pinning forces in a-axis oriented EuBa2Cu3O7/PrBa2Cu3O7 superlattices

    Science.gov (United States)

    Vélez, M.; Martín, J. I.; Vicent, J. L.

    1995-11-01

    a-axis oriented EuBa2Cu3O7/PrBa2Cu3O7 (EBCO/PBCO) superlattices have been grown by dc sputtering. The critical current (JC) behavior is modified by the pinning force arising from the insulating PrBa2Cu3O7 layers, which in a-axis oriented superlattices are perpendicular to the Cu-O planes. Depending on the EBCO and PBCO layer thicknesses the pinning forces deviate from the usual scaling laws as a function of temperature observed in single films. When B is perpendicular to the sample, an exponential dependence of JC(B) appears as the PBCO thickness is increased (coupling is reduced), and also as the thickness of the EBCO layer is reduced.

  16. Substitution of Au or Hg into BaTl2 and BaIn2. New ternary examples of smaller CeCu2-type intermetallic phases.

    Science.gov (United States)

    Dai, Jing-Cao; Corbett, John D

    2006-03-06

    The compounds BaAu(0.40(2))Tl(1.60(7)) (1), BaAu(0.36(4))In(1.64(4)) (2), and BaHg(0.92(2))In(1.08(2)) (3) have been prepared by high-temperature techniques. Single-crystal X-ray diffraction shows that these have the orthorhombic CeCu(2)-type structure, Imma, Z = 4 (a = 5.140(1), 5.104(1), 5.145(1) A; b = 8.317(2), 8.461(2), 8.373(2) A; c = 8.809(2), 8.580(2), 8.715(2) A, respectively). The structure consists of a four-linked honeycomblike polyanion (4(2)6(3)8) of infinity3[Tr2]2- (Tr = In or Tl) with encapsulated Ba2+ cations. The Au or Hg randomly replace Tr in a single type of site. The two gold phases exhibit appreciable nonstoichiometry ranges. Band calculations (EHTB) demonstrate that the three compounds are electron-poor and metallic, and the latter has been confirmed for 1 through resistivity and magnetic susceptibility measurements. The orthorhombic structure of 1 contrasts with the hexagonal structure of BaTl2 (CaIn2-type, P6(3)/mmc), a change that appears to be driven by substitution of the smaller Au atoms into the polyanion network. Relativistic effects for the heavier Au and Hg are evidently responsible for decreases in lattice parameters and bond lengths from BaIn2 to those in isostructural 2 and 3.

  17. The BaBar Data Reconstruction Control System

    Energy Technology Data Exchange (ETDEWEB)

    Ceseracciu, A

    2005-04-20

    The BaBar experiment is characterized by extremely high luminosity and very large volume of data produced and stored, with increasing computing requirements each year. To fulfill these requirements a Control System has been designed and developed for the offline distributed data reconstruction system. The control system described in this paper provides the performance and flexibility needed to manage a large number of small computing farms, and takes full benefit of OO design. The infrastructure is well isolated from the processing layer, it is generic and flexible, based on a light framework providing message passing and cooperative multitasking. The system is distributed in a hierarchical way: the top-level system is organized in farms, farms in services, and services in subservices or code modules. It provides a powerful Finite State Machine framework to describe custom processing models in a simple regular language. This paper describes the design and evolution of this control system, currently in use at SLAC and Padova on {approx}450 CPUs organized in 9 farms.

  18. The Enriched Xenon Observatory: EXO-200 and Ba+ tagging

    Science.gov (United States)

    Dolinski, M. J.; EXO Collaboration

    2012-08-01

    The Enriched Xenon Observatory (EXO) is a proposed ton-scale double beta decay experiment with a tentative design sensitivity to the Majorana mass of ˜10 meV. The first phase of EXO is EXO-200, which uses 200 kg of Xe enriched to 80% in 136Xe to search for neutrinoless double beta decay. EXO-200 is a liquid Xe time projection chamber with the ability to detect both scintillation and ionization signals. The detector is constructed from ultra-low background materials and is currently installed at the Waste Isolation Pilot Plant, a salt mine with a 1600 meter water equivalent overburden. The projected 2 year sensitivity for EXO-200 is T1/20ν>6.4×1025 y at 90% confidence level. Looking toward a ton-scale EXO, one unique feature of the experiment is the proposal to identify the barium daughter produced by 136Xe double beta decay on an event-by-event basis. This technique will allow for the elimination of all backgrounds other than the background from the two-neutrino double beta decay spectrum. The EXO Collaboration is exploring a number of options to implement Ba-daughter tagging in the next generation EXO experiment.

  19. Zooplankton community of Parnaíba River, Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Ludmilla Cavalcanti Antunes Lucena

    2015-03-01

    Full Text Available Aim:The objective of the present work is to present a list of species of zooplankton (Rotifera, Cladocera and Copepoda from the Parnaíba River. Additionally, we provide comments on their distribution along the river, and between dry and wet seasons.MethodsZooplankton was collected with a plankton net (60 µm mesh and concentrated into a volume of 80 mL for further analysis, during the dry (October 2010 and wet (April 2011 seasons. Sampling was restricted to the marginal areas at depths between 80 and 150 cm.ResultsA total of 132 species was recorded among the three zooplankton groups studied. During the dry season a total of 82 species was registered and 102 species was registered for the wet season. Rotifera contributed with 66.7% of the species, followed by Cladocera (26.5% and Copepoda (6.8%.ConclusionsThe richness of species observed was high compared to other large rivers in Brazil. In the context of current policies for water management and river diversions in northeastern Brazil, the present study highlights the importance of this river system for biodiversity conservation.

  20. Measurements of the CKM Angle Alpha at BaBar

    Energy Technology Data Exchange (ETDEWEB)

    Stracka, Simone; /Milan U. /INFN, Milan

    2012-04-04

    The authors present improved measurements of the branching fractions and CP-asymmetries fin the B{sup 0} {yields} {pi}{sup +}{pi}{sup -}, B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}, and B{sup +} {yields} {rho}{sup +}{rho}{sup 0} decays, which impact the determination of {alpha}. The combined branching fractions of B {yields} K{sub 1}(1270){pi} and B {yields} K{sub 1}(1400){pi} decays are measured for the first time and allow a novel determination of {alpha} in the B{sup 0} {yields} {alpha}{sub 1}(1260){sup {+-}}{pi}{sup {-+}} decay channel. These measurements are performed using the final dataset collected by the BaBar detector at the PEP-II B-factory. The primary goal of the experiments based at the B factories is to test the Cabibbo-Kobayashi-Maskawa (CKM) picture of CP violation in the standard model of electroweak interactions. This can be achieved by measuring the angles and sides of the Unitarity Triangle in a redundant way.

  1. The use of ICTS in the BA in English teaching

    Directory of Open Access Journals (Sweden)

    Charpentier Jiménez, William

    2014-01-01

    Full Text Available El presente artículo examina el papel de las Tecnologías de la Información y de la Comunicación (TIC en la enseñanza del idioma inglés. A través de una encuesta electrónica, se analizaron las opiniones de cincuenta egresados del Bachillerato en la Enseñanza del Inglés de la Universidad de Costa Rica. Los resultados muestran que las Tecnologías de la Información y de la Comunicación juegan un papel esencial en el aprendizaje de un idioma para el desarrollo de las macro destrezas lingüísticas. Basándose en estos resultados, se concluye que, a pesar de su importancia, las TIC no están completamente incorporadas en esta carrera. This article examines the role of information and communication technologies (ICTs in language teaching. Through an electronic survey, the opinions of fifty ex-students of the B.A. in the Teaching of English at the University of Costa Rica were analyzed. The results show that information and communication technologies play an essential role in language learning to develop the macro linguistic skills. Based on these results, it can be concluded that, despite their importance, ICTs are not being fully incorporated in the major.

  2. Preparation and Characterization of Ag-Doped BaTiO3 Conductive Powders

    Directory of Open Access Journals (Sweden)

    Sue Hao

    2011-01-01

    Full Text Available BaTiO3 powders doped with Ag at different Ag/Ba molar ratios were prepared by sol-gel method. The resistivity reached the lowest point of 5.644 Ω·m when Ag concentration was 0.10 at% and the powders were calcined for two times at 800°C and 500°C. XRD and FTIR investigations showed that no new substance was formed after the doping and calcining process, but the particle size and the strength of Ti-O bond in modified BaTiO3 crystal cell all changed. The conductivity of Ag-doped BaTiO3 powders with different Ag concentrations and through different preparing methods was discussed by using defect theory.

  3. Magneto-transport and electronic structures of BaZnBi2

    Science.gov (United States)

    Wang, Yi-Yan; Guo, Peng-Jie; Yu, Qiao-He; Xu, Sheng; Liu, Kai; Xia, Tian-Long

    2017-12-01

    We report the magneto-transport properties and electronic structures of BaZnBi2. BaZnBi2 is a quasi-two-dimensional material with metallic behavior. Transverse magnetoresistance (MR) depends on magnetic field linearly and exhibits Shubnikov–de Haas (SdH) oscillation at low temperature and high field. The observed linear MR may originate from the disorder in samples or the edge conductivity in compensated two-component systems. The first-principles calculations reveal the absence of stable gapless Dirac fermion. Combined with the trivial Berry phase extracted from the SdH oscillation, BaZnBi2 is suggested as a topologically trivial semimetal. Nearly compensated electron-like Fermi surfaces (FSs) and hole-like FSs coexist in BaZnBi2.

  4. submitter Performance simulation of BaBar DIRC bar boxes in TORCH

    CERN Document Server

    Föhl, K; Castillo García, L; Cussans, D; Forty, R; Frei, C; Gao, R; Gys, T; Harnew, N; Piedigrossi, D; Rademacker, J; Ros García, A; van Dijk, M

    2017-01-01

    TORCH is a large-area precision time-of-flight detector based on the DIRC principle. The DIRC bar boxes of the BaBar experiment at SLAC could possibly be reused to form a part of the TORCH detector time-of-flight wall area, proposed to provide positive particle identification of low momentum kaons in the LHCb experiment at CERN. For a potential integration of BaBar bar boxes into TORCH, new imaging readout optics are required. From the several designs of readout optics that have been considered, two are used in this paper to study the effect of BaBar bar optical imperfections on the detector reconstruction performance. The kaon-pion separation powers obtained from analysing simulated photon hit patterns show the performance reduction for a BaBar bar of non-square geometry compared to a perfectly rectangular cross section.

  5. Ba{sub 2}TeO as an optoelectronic material: First-principles study

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jifeng, E-mail: sun@magnet.fsu.edu [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Department of Chemical and Biomedical Engineering, College of Engineering, Florida Agricultural and Mechanical University-Florida State University, 2525 Pottsdamer St., Tallahassee, Florida 32310 (United States); National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310 (United States); Shi, Hongliang; Du, Mao-Hua; Singh, David J. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Siegrist, Theo [Department of Chemical and Biomedical Engineering, College of Engineering, Florida Agricultural and Mechanical University-Florida State University, 2525 Pottsdamer St., Tallahassee, Florida 32310 (United States); National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310 (United States)

    2015-05-21

    The band structure, optical, and defects properties of Ba{sub 2}TeO are systematically investigated using density functional theory with a view to understanding its potential as an optoelectronic or transparent conducting material. Ba{sub 2}TeO crystallizes with tetragonal structure (space group P4/nmm) and with a 2.93 eV optical bandgap [Besara et al., J. Solid State Chem. 222, 60 (2015)]. We find relatively modest band masses for both electrons and holes suggesting applications. Optical properties show infrared-red absorption when doped. This could potentially be useful for combining wavelength filtering and transparent conducting functions. Furthermore, our defect calculations show that Ba{sub 2}TeO is intrinsically p-type conducting under Ba-poor condition. However, the spontaneous formation of the donor defects may constrain the p-type transport properties and would need to be addressed to enable applications.

  6. The magnetic properties of the Ln sub 2 BaCuO sub 5

    Energy Technology Data Exchange (ETDEWEB)

    Salinas-Sanchez, A.; Saez-Puche, R.; Alario-Franco, M.A. (Universidad Complutense de Madrid (ES). Facultad de Ciencias Quimicas)

    1991-01-01

    The temperature dependence of the magnetic susceptibility for the different Ln{sub 2}BaCuO{sub 5} oxides (green phases) where Ln is Gd, Dy and Ho which after appears as impurities in the synthesis of high temperature superconductors, reveals the existence of antiferromagnetic ordering for both Cu and Ln sublattices. In the case of the isostructural Lu{sub 2}BaCuO{sub 5} the Cu{sup 2+} ions are ordered at about the same temperature found for Y{sub 2}BaCuO{sub 5}. The specific magnetic behavior of Nd{sub 2}BaCuO{sub 5} can be explained by considering its different structure-type.

  7. Data of evolutionary structure change: 1ELTA-2V0BA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1ELTA-2V0BA 1ELT 2V0B A A VVGGRVAQPNSWPWQISLQYKSGSSYYHTCGGSLIRQGW...VGGTEAQRNSWPSQISLQYRSGSSWAHTCGGTLIRQNWVMTAAHCVDRELTFRVVVGEHNLNQNDGTEQYVGVQKIVVHPY...E EEEEEEEEEEEE EEEEEEGG HHHHHHHHH 0 1ELT... A 1ELTA

  8. [Construction of a recombinant stable Ba/F3 cell strain containing Tpr-Met].

    Science.gov (United States)

    Shu, Ling-fei; Li, Wei; Zhan, Yi-qun; Xu, Wang-xiang; Yang, Xiao-ming; Li, Chang-yan

    2012-11-01

    To construct a stable cell strain encoding tumor-associated fused gene which expresses oncoprotein Tpr-Met. We transfected Tpr-Met vector into Ba/F3 cells and screened the cell strain stably expressing Tpr-Met. The interleukin 3 (IL-3) independent proliferation of the cells was measured using the MTS assay. The expression of Tpr-Met, the activity of downstream signal transduction pathway and SU11274-induced inhibition of the signal pathway were investigated by Western blotting. We obtained a Ba/F3 cell strain stably expressing Tpr-Met. The cells presented IL-3 independent proliferation, suggesting a malignant transformation of the cell line. In Tpr-Met transformed Ba/F3 cells, the phosphorylation of Met and ERK were enhanced; however, specific c-Met inhibitor SU11274 suppressed the cell proliferation and c-Met phosphorylation. Tpr-Met transformed Ba/F3 strain has been successfully constructed.

  9. Surfactant-assisted synthesis of BaTiO3 nanoparticles by micro-emulsion method

    Directory of Open Access Journals (Sweden)

    J. L. Gao

    2015-10-01

    Full Text Available Barium titanate (BaTiO3 nanoparticles were successfully synthesized by using a surfactant-assisted method. The various processing parameters, namely, th e species of surfactant, reaction temperature and micro-emusion concentration had been varied, and the effects on the micrographs and crystal structure of BaTiO3 particles had been analyzed by scanning electron microscope (SEM, transmission electron microscopy (TEM and X-ray diffraction (XRD. XRD analyses confirming the tetragonal structure of the BaTiO3 nanoparticles using hexadecyl trimethyl ammonium Bromide (CTAB or nonylphenol polyoxyethylene ether (NP-10 as surfactant. The SEM analysis showed that by changing the species of surfactant, grains with different dimensions could be synthesized. TEM analyses indicate that BaTiO3 nanoparticles with 15–20 nm in diameter were successfully synthesized.

  10. Formation and Photocatalytic Activity of BaTiO3 Nanocubes via Hydrothermal Process

    Directory of Open Access Journals (Sweden)

    Xinrun Xiong

    2015-01-01

    Full Text Available We reported a facile hydrothermal approach to synthesize BaTiO3 nanocubes with controlled sizes for degradation of methylene blue (MB. The nanocubes with reaction time of 48 hours exhibited the highest photocatalytic efficiency, owing to their narrower size distribution and better crystallinity compared to those of 24 hours and, at the meantime, smaller particle size than those of 72 hours. This work also demonstrated the degradation of methylene orange (MO using BaTiO3 nanocubes synthesized for 48 hours. Compared with the removal of MB, BaTiO3 had lower photocatalytic activity on MO, mainly due to the poorer absorption behavior of MO on the surface of BaTiO3 nanocubes. The degradation efficiency for each photocatalytic reaction was calculated. The possible mechanism of the photocatalytic decomposition on MB has been addressed as well.

  11. Hydrothermal synthesis of tetragonal BaTiO3 nanotube arrays with high dielectric performance.

    Science.gov (United States)

    Wang, Liming; Deng, Xiangyun; Li, Jianbao; Liao, Xinxing; Zhang, Guoqing; Wang, Chunpeng; Su, Kuifan

    2014-06-01

    Tetragonal Barium titanate (BaTiO3) nanotube arrays have been prepared using the template-assisted hydrothermal method combined with an annealing process. The in-situ chemical conversion of TiO2 nanotube array templates ensured that BaTiO3 maintained the morphology of the nanotube architectures. Moreover, X-ray diffraction and Raman spectrum characterization were used to confirm that the BaTiO3 nanotube arrays had a tetragonal phase after the use of a simple annealing technique. Typical hysteresis loops showed their ferroelectricity, with the remanent polarization and coercive fields being 2.57 microC/cm2 and 2.52 kV/cm, respectively. The relative dielectric constant of the tetragonal BaTiO3 nanotube arrays reached up to 1000 and the dielectric loss was as low as 0.02 at 1 kHz at room temperature.

  12. Formation of new structural states in compressed BaTiO3 nanopowders

    Science.gov (United States)

    Shmyt'ko, I. M.; Frolov, D. D.; Aronin, A. S.; Ganeeva, G. R.; Kedrov, V. V.

    2017-06-01

    The structural changes in BaTiO3 nanocrystal powder and tablets have been probed via X-ray diffraction, scanning electron and transmission microscopy, and differential calorimetry after successive hightemperature annealing in air. It is shown that, beginning with the annealing temperature of 1200°C, significant amount of the Ba2TiO4 phase forms in the tablets together with the BaTiO3 phase. This phase is equilibrium one; it practically vanishes when the annealing temperature decreases to 700-600°C; and this phase practically restored to the initial state when the annealing temperature is again increased to 1200°C. Annealing the powders causes no formation of new phases, but an increase in their crystallite sizes. A probable reason of the emergence of Ba2TiO4 phase in tablets and its absence in free powder is discussed, as well.

  13. Influence Cr on Crystallization and the Phase Transformations of the Bronze BA1044

    Directory of Open Access Journals (Sweden)

    B. P. Pisarek

    2007-07-01

    Full Text Available The investigations were introduced in the paper, method of thermal and derivative analysis (TDA, the process of crystallization and phase transformation in the solid state of the aluminium bronze CuA110Fe4Ni4 (BA1044 and with the addition 0.3% Cr. Two intermetallic phase were identified in the microstructure of the bronze BA1044: κFel - rich in Fe and Cu and κFe2 - rich in Fe, and in the microstructure of the bronze BA1044+0.3 % Cr only one phase κFel - rich in Fe, Cu and Cr. The presence of chrome in the bronze BA1044 reduce size the primary crystals of the phase β, reduces the dynamics of the processes of thermal phase transformation in the solid state and lengthens the time their of duration.

  14. Separation of Sr from Ca, Ba and Ra by means of Ca(OH)2 and Ba(Ra)Cl2 or Ba(Ra)SO4 for the determination of radiostrontium

    DEFF Research Database (Denmark)

    Chen, Q.J.; Hou, Xiaolin; Yu, Y.X.

    2002-01-01

    be completed. The new separation procedure has been successfully used for the determination of Sr-90 in samples with high Ca content, such as 451 of seawater and 2001 of drinking water. The analytical quality of the results is comparable to that of the traditional method using fuming nitric acid and BaCrO4...

  15. Ca, Sr and Ba stable isotopes reveal the fate of soil nutrients along a tropical climosequence

    Science.gov (United States)

    Bullen, Thomas D.; Chadwick, Oliver A.

    2016-01-01

    Nutrient biolifting is an important pedogenic process in which plant roots obtain inorganic nutrients such as phosphorus (P) and calcium (Ca) from minerals at depth and concentrate those nutrients at the surface. Here we use soil chemistry and stable isotopes of the alkaline earth elements Ca, strontium (Sr) and barium (Ba) to test the hypothesis that biolifting of P has been an important pedogenic process across a soil climosequence developed on volcanic deposits at Kohala Mountain, Hawaii. The geochemical linkage between these elements is revealed as generally positive site-specific relationships in soil mass gains and losses, particularly for P, Ba and Ca, using the ratio of immobile elements titanium and niobium (Ti/Nb) to link individual soil samples to a restricted compositional range of the chemically and isotopically diverse volcanic parent materials. At sites where P is enriched in surface soils relative to abundances in deeper soils, the isotope compositions of exchangeable Ca, Sr and Ba in the shallowest soil horizons (volcanic parent materials and trend toward those of plants growing on fresh volcanic deposits. In contrast the isotope composition of exchangeable Ba in deeper soil horizons (> 10 cm depth) at those sites is consistently heavier than the volcanic parent materials. The isotope compositions of exchangeable Ca and Sr trend toward heavier compositions with depth more gradually, reflecting increasing leakiness from these soils in the order Ba soils, a simple box model demonstrates that persistence of isotopically light exchangeable Ca, Sr and Ba in the shallowest soil horizons requires that the uptake flux to plants from those near-surface layers is less than the recycling flux returned to the surface as litterfall. This observation implicates an uptake flux from an additional source which we attribute to biolifting. We view the heavy exchangeable Ba relative to soil parent values in deeper soils at sites where P is enriched in surface soils

  16. Effect of magnetic field on the temperature gradient in Y1Ba2Cu3O7 - δ + Eu1Ba2Cu3O7 - δ rods

    Science.gov (United States)

    Churin, S. A.

    2009-05-01

    A method for growing Y1Ba2Cu3O7 - δ + Eu1Ba2Cu3O7 - δ (YBCO-EBCO) high-temperature superconductor rods is described. The temperature dependences of the resistance of rods in a magnetic field of B = 0.6 T and in the absence of the field ( B = 0 T) are presented. The current-voltage characteristics of YBCO-EBCO rods have been measured at liquid nitrogen temperature have been measured in the absence and presence of a magnetic field. It is shown that the magnetic field significantly decreases the temperature gradient arising when the rod leaves the superconducting state.

  17. Scanning Auger microscopy analysis of 90 K Y--Ba--Cu--O superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Cota, L.; Morales de la Garza, L.; Hirata, G.; Martinez, L.; Orozco, E.; Carrillo, E.; Mendoza, A.; Albarran, J.L.; Fuentes-Maya, J.; Boldu, J.L.; and others

    1988-05-01

    The oxide superconductor Y--Ba--Cu--O is studied using Auger scanning microscopy. The chemical depth profiles of the samples were obtained. It is concluded that two phases are present in the sample, one corresponding to the standard composition and another that is Ba enriched. The first shows a platelet shape and the second a granular appearence that covers the surface of the sample.

  18. Resistance to micro-plastic deformation in superconducting Y-Ba-Cu-O

    Science.gov (United States)

    Nishi, Yoshitake; Tokunaga, Shigeki; Toyama, Toshinobu

    1988-01-01

    The stress-strain behavior of a Y-Ba-Cu-O superconducting ceramic (Tc above 90 K) is investigated experimentally under conditions of microplastic deformation using X-ray diffraction analysis and Vickers hardness measurements. The resistance of YBa2Cu3O(9-y) specimens to microplastic deformation is estimated at HV 520 at the surface and 300 in the bulk. It is further shown that polishing increases Tc by removing a surface layer of sintered Y-Ba-Cu oxide.

  19. Lithium insertion in Ba sub 2 YCu sub 3 O sub 7-y

    Energy Technology Data Exchange (ETDEWEB)

    Alario-Franco, M.A.; Moran, E.; Varez, A. (Dept. de Quimica Inorganica 1, Univ. Complutense, Madrid (Spain)); Santamaria, J.; Sanchez-Quesada, F. (Dept. de Fisica Aplicada 3, Univ. Complutense, Madrid (Spain))

    1990-12-01

    Novel materials, Li{sub x}Ba{sub 2}YCu{sub 3}O{sub 7-y}(0{<=}x{<=}2), have been obtained by reaction of Ba{sub 2}YCu{sub 3}O{sub 7-y} with n-butyllithium. The most striking feature of these materials is the coexistence of both ionic conductivity and superconductivity for 0

  20. Characterization, dielectric and electrical behaviour of BaTiO3 ...

    Indian Academy of Sciences (India)

    Administrator

    thick suspension of BaTiO3 nanoparticles were spread on a carbon conductive tape attached to the surface of SEM brass stub. The particles on the stub were coated with gold–palladium by plasma sputtering for 3 min for the preparation for FE–SEM imaging. The FE–SEM image of. BaTiO3 nanoparticles prepared is shown ...

  1. Characterization, dielectric and electrical behaviour of BaTiO3 ...

    Indian Academy of Sciences (India)

    A new sol-precipitation technique for the preparation of nano BaTiO3 crystallite has been developed by reacting 0.2 M each of Ti(IV) triethanolaminato isopropoxide and hydrated barium hydroxide in methanol such that the molar ratio of Ba : Ti is 1.02 at 80 °C under stirring (1200 rpm) for one hour in alkaline media using ...

  2. How Extended Is Wernicke's Area? Meta-Analytic Connectivity Study of BA20 and Integrative Proposal

    OpenAIRE

    Alfredo Ardila; Byron Bernal; Monica Rosselli

    2016-01-01

    Understanding the functions of different brain areas has represented a major endeavor of contemporary neurosciences. The purpose of this paper was to pinpoint the connectivity of Brodmann area 20 (BA20) (inferior temporal gyrus, fusiform gyrus) in language tasks. A meta-analysis was conducted to assess the language network in which BA20 is involved. The DataBase of Brainmap was used; 11 papers corresponding to 12 experimental conditions with a total of 207 subjects were included in this analy...

  3. Fabrication of Perovskite-type Oxide BaPbO Nanoparticles and their ...

    African Journals Online (AJOL)

    NICO

    ized by XRD, TEM, SEM, EDX and IR techniques. The photocatalytic activity of ... (BaPbO3) is crystal at 700 °C. The XRD, TEM and SEM revealed that BaPbO3 particles are prepared in the nano-size regime. The results show that the ... colour).4 Dyes are classi- fied according to chemical structure and type of application.

  4. Microcalorimetric study of carbon dioxide adsorption in BaY zeolite

    OpenAIRE

    RAKHMATKARIEVA FERUZA; RAKHMATKARIEV GAIRAT; GURO VITALY PAVLOVICH

    2015-01-01

    Differential heats and isotherm of carbon dioxide adsorption in a zeolite ВaY have been measured by Tian-Calvet-type microcalorimeter and volumetric system at 303 K. Based on the data obtained, the mechanism of (CO2)n/Ba 2+ complexes formation in the zeolitic matrix of BaY is revealed. The adsorption isotherm is quantitatively reproduced by VOM theory equations.

  5. The relationship of structure to superconductivity in the Pr-Ba-Cu-O system

    Energy Technology Data Exchange (ETDEWEB)

    Minseo, Park [Iowa State Univ., Ames, IA (United States)

    1994-05-10

    The relation of structure to lack of superconductivity in Pr-Ba-Cu-O was systematically investigated. First, the phase equilibria of this system was studied to find the processing parameters which maximize the cation-site ordering between Pr and Ba ions. Second, a comparative study between superconducting Nd-Ba-Cu-0 and non- superconducting Pr-Ba-Cu-0 was performed by forming solid-solution Nd- Pr-Ba-Cu-0. The relation between structure and superconductivity in Ndb1-xPrxBa2Cu3O7-δ is investigated. Tc decreases monotonically with increasing x and superconductivity disappears at around x=0.3-0.4. Tc is enhanced by 10K when the sample is processed at an oxygen partial pressure (PO2) of 0.01 atm, followed by oxygenation at 450C. Depression of (Tc) as a function of x and PO 2 is explained in terms of a charge-transfer model. It is suggested that destruction of superconductivity in the RE1-xPrxBa2CU3O7-δ (RE=rare-earth) system can be viewed as disruption of four-fold planar coordinated Cu ions in the chain-site due to permanent occupation of extra Pr ions on Ba sites.

  6. Structural Distortion Stabilizing the Antiferromagnetic and Semiconducting Ground State of BaMn2As2

    Directory of Open Access Journals (Sweden)

    Ekkehard Krüger

    2016-09-01

    Full Text Available We report evidence that the experimentally found antiferromagnetic structure as well as the semiconducting ground state of BaMn 2 As 2 are caused by optimally-localized Wannier states of special symmetry existing at the Fermi level of BaMn 2 As 2 . In addition, we find that a (small tetragonal distortion of the crystal is required to stabilize the antiferromagnetic semiconducting state. To our knowledge, this distortion has not yet been established experimentally.

  7. Introduction of Culex Toxicity into Bacillus thuringiensis Cry4Ba by Protein Engineering

    OpenAIRE

    Abdullah, Mohd Amir F.; Alzate, Oscar; Mohammad, Marwan; McNall, Rebecca J.; Adang, Michael J.; Dean, Donald H.

    2003-01-01

    Bacillus thuringiensis mosquitocidal toxin Cry4Ba has no significant natural activity against Culex quinquefasciatus or Culex pipiens (50% lethal concentrations [LC50], >80,000 and >20,000 ng/ml, respectively). We introduced amino acid substitutions in three putative loops of domain II of Cry4Ba. The mutant proteins were tested on four different species of mosquitoes, Aedes aegypti, Anopheles quadrimaculatus, C. quinquefasciatus, and C. pipiens. Putative loop 1 and 2 exchanges eliminated acti...

  8. Photoluminescence of water-soluble NdF nanoparticles by codoping Li or Ba ions

    Science.gov (United States)

    Fan, Ting; Lü, Jiantao; Li, Na; Han, Dingan

    2013-02-01

    Water-soluble NdF3, NdF3:Li+, and NdF3:Ba nanoparticles coated with polyvinylpyrrolidone were synthesized by a simple hydrothermal method. The products were characterized by x-ray diffraction, field-emission scanning electron microscopy, and photoluminescence spectra at room temperature. Codoping with Li+ ions does not change the emission intensity of water-soluble NdF3 nanoparticles, whereas codoping with Ba ions improves the near-infrared emissions.

  9. Ba2ErNbO6: A new perovskite ceramic substrate for Bi (2223 ...

    Indian Academy of Sciences (India)

    Barium erbium niobate (Ba2ErNbO6) has been developed as a new substrate for (Bi,Pb)2Sr2Ca2Cu3O [Bi(2223)] superconductor film. Ba2ErNbO6 (BENO) has a cubic perovskite structure with lattice constant, = 8.318 Å. The Bi(2223) superconductor does not show any detectable chemical reaction with BENO even ...

  10. Plastic debris ingestion by sea turtle in Paraíba, Brazil.

    Science.gov (United States)

    Mascarenhas, Rita; Santos, Robson; Zeppelini, Douglas

    2004-08-01

    Coastal gill net entanglement and debris intake are important threats to the survival of sea turtles. Two sea turtles (Lepidochelys olivacea and Chelonia mydas) were found stranded along the coast of Paraíba. After necropsy, plastic debris were found in the stomach. The debris is described. This is the first record of this sort of problem for the Paraíba littoral.

  11. An investigation of new infrared nonlinear optical material: BaCdSnSe4, and three new related centrosymmetric compounds: Ba2SnSe4, Mg2GeSe4, and Ba2Ge2S6.

    Science.gov (United States)

    Wu, Kui; Su, Xin; Yang, Zhihua; Pan, Shilie

    2015-12-14

    A series of new metal chalcongenides, BaCdSnSe4 (1), Ba2SnSe4 (2), Mg2GeSe4 (3), and Ba2Ge2S6 (4), were successfully synthesized for the first time. Among them, compounds 2 and 4 were prepared by a molten flux method with Zn as the flux. In their structures, all of them have MQ4 (M = Sn, Ge; Q = S, Se) units. For compound 1, the CdSe4 and SnSe4 groups are connected to form CdSnSe6 layers and these layers are linked together by the Ba atoms. Compounds 2 and 3 are composed of isolated MSe4 (M = Sn, Ge) units and charge-balanced by the Ba or Mg atoms, respectively, while compound 4 has infinite ∞(GeS3)n chains, which is different from the structures of the other three compounds that only have isolated MSe4 (M = Sn, Ge) units. The measured IR and Raman data of the title compounds show wide infrared transmission ranges. The experimental band gaps of compounds 1, 2, 3 and were determined to be 1.79, 1.90, and 2.02 eV, respectively. Band structures were also calculated and indicate that their tetrahedral units, such as [SnSe4], [GeS4] and [GeSe4], determine the energy band gaps of the title compounds, respectively. As for compound 1, based on fundamental light at 2.09 μm, the experimental second harmonic generation (SHG) response is about 1.6 times that of the benchmark AgGaS2, which is also consistent with the calculated value. Based on the above results, compound 1 has promising applications in the IR field as a NLO material.

  12. About room temperature ferromagnetic behavior in BaTiO{sub 3} perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, G., E-mail: memodin@yahoo.com [Departamento de Física, CINVESTAV-IPN, A.P. 14-740, México DF 07360, México (Mexico); Escuela Superior de Física y Matemáticas del Instituto Politécnico Nacional, U.P.A.L.M, Edificio 9, Av. Instituto Politécnico Nacional S/N, San Pedro Zacatenco, México DF 07738, México (Mexico); Conde-Gallardo, A. [Departamento de Física, CINVESTAV-IPN, A.P. 14-740, México DF 07360, México (Mexico); Montiel, H. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico de la Universidad Nacional Autónoma de México, Cd. Universitaria, A.P. 70-186, México DF 04510, México (Mexico); Zamorano, R. [Escuela Superior de Física y Matemáticas del Instituto Politécnico Nacional, U.P.A.L.M, Edificio 9, Av. Instituto Politécnico Nacional S/N, San Pedro Zacatenco, México DF 07738, México (Mexico)

    2016-03-01

    A ferromagnetic behavior at room temperature is detected in micro-, submicro- and nano-powders of BaTiO{sub 3} perovskite by means of magnetization measurements, where the magnetic response is originated of different sources, depending on nature of the sample. For BaTiO{sub 3} micropowders is associated with the presence of a magnetic impurity, while for submicro- and nano-powders of BaTiO{sub 3} perovskite, the ferromagnetism is due to magnetic moments arising from the oxygen vacancies on the particles surface. We carry out an additional experimental confirmation of our asseverations by means of the electron paramagnetic resonance (EPR) and the low-field microwave absorption (LFMA), at X-band (8.8–9.8 GHz) and 300 K, indicating the presence of a magnetic impurity in BaTiO{sub 3} micropowders and the existence of oxygen vacancies in BaTiO{sub 3} nanopowders. - Highlights: • Ferromagnetism at 300 K is detected in diverse powders of BaTiO{sub 3} perovskite. • EPR and LFMA techniques are used to investigate the origin of this ferromagnetism. • We discuss on presence of a magnetic impurity and oxygen vacancies in these powders.

  13. Thermoelectric properties of Cu/Ag doped type-III Ba24Ge100 clathrates

    Science.gov (United States)

    Fu, Jiefei; Su, Xianli; Yan, Yonggao; Liu, Wei; Zhang, Zhengkai; She, Xiaoyu; Uher, Ctirad; Tang, Xinfeng

    2017-09-01

    Type-III Ba24Ge100 clathrates possess low thermal conductivity and high electrical conductivity at room temperature and, as such, have a great potential as thermoelectric materials for power generation. However, the Seebeck coefficient is very low due to the intrinsically high carrier concentration. In this paper, a series of Ba24CuxGe100-x and Ba24AgyGe100-y specimens were prepared by vacuum melting combined with the subsequent spark plasma sintering (SPS) process. Doping Cu or Ag on the Ge site not only suppresses the concentration of electrons but it also decreases the thermal conductivity. In addition, the carrier mobility and the Seebeck coefficient increase due to the decrease in the carrier concentration. Thus, the power factor is greatly improved, leading to an improvement in the dimensionless figure of merit ZT. Cu-doped Ba24Cu6Ge94 reaches the maximum ZT value of about 0.17 at 873 K, while Ag-doped Ba24Ag6Ge94 attains the dimensionless figure of merit ZT of 0.31 at 873 K, more than 2 times higher value compared to un-doped Ba24Ge100.

  14. Enhanced resistive memory in Nb-doped BaTiO3 ferroelectric diodes

    Science.gov (United States)

    Jin, Qiao; Zheng, Chunyan; Zhang, Yongcheng; Lu, Chaojing; Dai, Jiyan; Wen, Zheng

    2017-07-01

    In this study, we report on enhanced resistive memory in BaTiO3-based ferroelectric diodes due to the doping of donors. A large ON/OFF current ratio of ˜2000, about two orders of magnitude higher than that of Au/BaTiO3/SrRuO3, is achieved in a Au/Nb:BaTiO3/SrRuO3 diode at room temperature. This can be ascribed to the enhanced ferroelectric-modulation on the potential barrier at the Nb:BaTiO3/SrRuO3 interface associated with the (NbTi4+ 5 +) . donors, which gives rise to an efficient control of device transport between a bulk-limited current in the ON state and an interface-limited Schottky emission in the OFF state. In contrast, the resistance switching is suppressed in a Au/Fe:BaTiO3/SrRuO3 device since the (FeTi4+ 3 +) ' acceptors suppress semiconducting character of the BaTiO3 thin film and make the polarization-modulation of the band diagram negligible. The present work facilitates the design of high-performance resistive memory devices based on ferroelectric diodes with controllable charged defects.

  15. Synthesis and luminescent properties of novel BaGd2O4:Eu3+ scintillating phosphor.

    Science.gov (United States)

    Sun, Xin-Yuan; Wang, Wen-Feng; Sun, Shou-Qiang; Lin, Liang-Wu; Li, De-Yi; Zhou, Ling-Ping

    2013-01-01

    BaGd2-x O4:xEu(3+) and Ba1-y Gd1.79-2y Eu0.21 Na3y O4 phosphors were synthesized at 1300°C in air by conventional solid-state reaction method. Phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence excitation (PLE) spectra, photoluminescence (PL) spectra and thermoluminescence (TL) spectra. Optimal PL intensity for BaGd2-x O4 :xEu(3+) and Ba1-y Gd1.79-2y Eu0.21 Na3y O4 phosphors at 276 nm excitation were found to be x = 0.24 and y = 0.125, respectively. The PL intensity of Eu(3+) emission could only be enhanced by 1.3 times with incorporation of Na(+) into the BaGd2 O4 host. Enhanced luminescence was attributed to the flux effect of Na(+) ions. However, when BaGd2 O4:Eu(3+) phosphors were codoped with Na(+) ions, the induced defects confirmed by TL spectra impaired the emission intensity of Eu(3+) ions. Copyright © 2012 John Wiley & Sons, Ltd.

  16. Environmental stress-dependent effects of deletions encompassing Hsp70Ba on canalization and quantitative trait asymmetry in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Kazuo H Takahashi

    Full Text Available Hsp70 genes may influence the expression of wing abnormalities in Drosophila melanogaster but their effects on variability in quantitative characters and developmental instability are unclear. In this study, we focused on one of the six Hsp70 genes, Hsp70Ba, and investigated its effects on within- and among-individual variability in orbital bristle number, sternopleural bristle number, wing size and wing shape under different environmental conditions. To do this, we studied a newly constructed deletion, Df(3RED5579, which encompasses Hsp70Ba and nine non-Hsp genes, in the heterozygous condition and another, Hsp70Ba(304, which deletes only Hsp70Ba, in the homozygous condition. We found no significant effect of both deletions on within-individual variation quantified by fluctuating asymmetry (FA of morphological traits. On the other hand, the Hsp70Ba(304/Hsp70Ba(304 genotype significantly increased among-individual variation quantified by coefficient of variation (CV of bristle number and wing size in female, while the Df(3RED5579 heterozygote showed no significant effect. The expression level of Hsp70Ba in the deletion heterozygote was 6 to 20 times higher than in control homozygotes, suggesting that the overexpression of Hsp70Ba did not influence developmental stability or canalization significantly. These findings suggest that the absence of expression of Hsp70Ba increases CV of some morphological traits and that HSP70Ba may buffer against environmental perturbations on some quantitative traits.

  17. Effect of Glow-to-Arc Transition on Loss Mechanism of Ba Atoms from Electrode of Fluorescent Lamp

    Science.gov (United States)

    Ueda, Takashi; Samir, Ahmed; Egashira, Yuichi; Yamashita, Go; Shimada, Shozaburo; Yamagata, Yukihiko; Uchino, Kiichiro; Manabe, Yoshio

    2007-10-01

    The loss of Ba atoms from the electrode of a fluorescent lamp was measured while the lamp was operated in the glow and arc discharge modes at 60 Hz. A laser-induced fluorescence (LIF) technique was applied to the measurements of the temporal and spatial distributions of Ba atoms in the vicinity of the electrode. Ground-state (61S0) Ba atoms were excited to a 51P1 level by a frequency-doubled dye laser beam (350.1 nm), and the subsequent fluorescence (51P1-51D2, 582.6 nm) was detected. The temporal and spatial distributions of Ba atoms were found to be completely different in the two discharge modes. Temporally; in the arc discharge mode, the density of the Ba atoms was found to have two peaks, and the number of Ba atoms emitted in the anode half-cycle was about twofold larger than that emitted in the cathode half-cycle. In the glow discharge mode, the number of Ba atoms emitted in the anode half-cycle was found to be negligible compared with that emitted in the cathode half-cycle. Spatially; in the arc discharge mode, Ba atoms were found to be emitted mainly from the hot spot of the filament electrode. In the glow discharge mode, Ba atoms were found to be emitted from all parts of the filament electrodes homogeneously. The mechanism of Ba atom loss in both modes was discussed.

  18. Environmental Stress-Dependent Effects of Deletions Encompassing Hsp70Ba on Canalization and Quantitative Trait Asymmetry in Drosophila melanogaster

    Science.gov (United States)

    Takahashi, Kazuo H.; Daborn, Phillip J.; Hoffmann, Ary A.; Takano-Shimizu, Toshiyuki

    2011-01-01

    Hsp70 genes may influence the expression of wing abnormalities in Drosophila melanogaster but their effects on variability in quantitative characters and developmental instability are unclear. In this study, we focused on one of the six Hsp70 genes, Hsp70Ba, and investigated its effects on within-and among-individual variability in orbital bristle number, sternopleural bristle number, wing size and wing shape under different environmental conditions. To do this, we studied a newly constructed deletion, Df(3R)ED5579, which encompasses Hsp70Ba and nine non-Hsp genes, in the heterozygous condition and another, Hsp70Ba304, which deletes only Hsp70Ba, in the homozygous condition. We found no significant effect of both deletions on within-individual variation quantified by fluctuating asymmetry (FA) of morphological traits. On the other hand, the Hsp70Ba304/Hsp70Ba304 genotype significantly increased among-individual variation quantified by coefficient of variation (CV) of bristle number and wing size in female, while the Df(3R)ED5579 heterozygote showed no significant effect. The expression level of Hsp70Ba in the deletion heterozygote was 6 to 20 times higher than in control homozygotes, suggesting that the overexpression of Hsp70Ba did not influence developmental stability or canalization significantly. These findings suggest that the absence of expression of Hsp70Ba increases CV of some morphological traits and that HSP70Ba may buffer against environmental perturbations on some quantitative traits. PMID:21541022

  19. Core–shell-structure Ag–BaTiO{sub 3} composite nanopowders prepared directly by flame spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seung Ho; Ko, You Na; Lee, Jung-Kul [Department of Chemical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of); Park, Byung Kyu [Suncheon Center, Korea Basic Science Institute, Suncheon 540-742 (Korea, Republic of); Kang, Yun Chan, E-mail: yckang@konkuk.ac.kr [Department of Chemical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)

    2013-06-15

    Core–shell-structure Ag–BaTiO{sub 3} composite nanopowders are prepared directly by flame spray pyrolysis. The single-crystalline Ag was located in the core part of the composite powder, and the Ba and Ti components are uniformly distributed in the shell part. The X-ray diffraction (XRD) patterns of the Ag–BaTiO{sub 3} composite powders have the main crystal peaks of Ag and broad peaks at around 28°. The Ag–BaTiO{sub 3} pellets with low Ag contents (below 20 wt%) have a dense structure and fine grain size. Abnormal grain growth of the Ag(30 wt%)–BaTiO{sub 3} pellets occurs even at a low sintering temperature of 1000 °C. The Ag–BaTiO{sub 3} pellet had a mixed crystal structure of BaTiO{sub 3} and Ag phases. Silver is uniformly distributed in the BaTiO{sub 3} matrix without phase separation. The dielectric constants of the BaTiO{sub 3}, Ag(10 wt%)–BaTiO{sub 3}, and Ag(30 wt%)–BaTiO{sub 3} pellets are 830, 2130, and 4680, respectively. - Highlights: • Core–shell-structure Ag–BaTiO{sub 3} nanopowders are prepared by flame spray pyrolysis. • The single-crystalline Ag is located in the core part of the composite nanopowders. • The dielectric constant of the Ag(30 wt%)–BaTiO{sub 3} pellet is high as 4680.

  20. Ba(Mg1/3Nb2/3)O3−xBa(Mg1/8Nb3/4)

    Indian Academy of Sciences (India)

    2017-09-05

    Sep 5, 2017 ... which have application in wireless communications. Their high permittivity (εr), high quality ... ture disorders. High-temperature treatment also results into secondary phases that deteriorate dielectric properties. Kolo- diazhnyi et al [7] reported ordering for BMN ceramics at. 1620. ◦. C, along with Ba3Nb5O15 ...

  1. The Scale Formation of Barite (BaSO4) from Laminar Flowing Water in The Presence of Tartaric Acid and Ba2+ Concentration Variation of Solution

    Science.gov (United States)

    Fatra, F.; Ivanto, G.; Dera, N. S.; Muryanto, S.; Bayuseno, A. P.

    2017-05-01

    The barite (BaSO4) scale is a mineral deposit that can be precipitated during the process of drilling oil and gas in the offshore. Deposite scale in pipes can cause a narrowing of the diameter of pipes, and can reduce water flowing in the pipe. The aim of this study is to investigation the effect of the tartaric acid additive and Ba2+ concentration on the growth o the scale formation of barite in the laminar flow of the piping system. Solution forming barite crystal was prepared by mixing equimolar solutions of barium chloride (BaCl2) and sodium sulfate (Na2SO4) with concentration variations of Ba2+ of 3000, 3500, 4000, 4500, and 5000 ppm. The flow rate of solution is 40 ml/min at temperature of 50 °C. Various concentrations of tartaric acid (C4H6O6) of 0 ppm, 5 ppm and 10 ppm were added to the solutions. The formation of barite from the solution was observed by ion conductivity measurement. The obtained barite crystals before and after adding tartaric acid were dried and characterized by using SEM/EDX for morphology and elemental analysis, and XRD for phase identification. The SEM results show that the morphology of the crystals are star-like particles, while XRD analysis confirmed that the barite crystals were produced during the experiments are high purity. Moreover, the tartaric acid can inhibit the crystal growth of barite.

  2. Improvement in magnetic properties of La substituted BaFe{sub 12}O{sub 19} particles prepared with an unusually low Fe/Ba molar ratio

    Energy Technology Data Exchange (ETDEWEB)

    Soezeri, H., E-mail: huseyin.sozeri@ume.tubitak.gov.t [TUBITAK-UME, National Metrology Institute, PO Box 54, TR-41470, Gebze-Kocaeli (Turkey); Kuecuek, I. [Physics Department, Faculty of Arts and Sciences, Uludag University, Gorukle Campus, 16059 Bursa (Turkey); Ozkan, H. [Physics Department, Middle East Technical University, 06531 Ankara (Turkey)

    2011-07-15

    In this study, effect of lanthanum substitution on the phase composition, lattice parameters and magnetic properties of barium hexaferrite has been studied in samples synthesized in ammonium nitrate melt. Samples, prepared with different lanthanum amount and having various initial Fe/(Ba+La) ratios in between 12 and 2 {l_brace}(Ba{sub 1-x}La{sub x}).n Fe{sub 2}O{sub 3}, where 0{<=}x{<=}1 and 1{<=}n{<=}6){r_brace}, are sintered at temperatures from 800 to 1200 {sup o}C. The lattice parameters, both a and c, decreases with increasing La amount which results in a decrease of the unit cell volume. The scanning electron microscope micrographs show that the pure and La-substituted sample with x=0.3, both calcinated at 1000 {sup o}C, have grain sizes smaller than 1 {mu}m. The coercivities of the La-substituted samples increase with increasing La amount and reaches to a maximum value of 5.73 kOe, when x=0.3. Sintering at higher temperatures (above 1000 {sup o}C) decreases the coercivity, resembling a transition from single to multi-domain behavior of the particles, while saturation magnetization of the samples continues to increase due to the increasing grain size. Magnetization measurements of the samples prepared with different Fe/(Ba+La) molar ratios, n's, revealed that the specific saturation magnetization slightly increases with decreasing n, while coercivities fluctuates around 5.5 kOe. However, a sharp increase in the saturation magnetization has been observed in the sample having n=1 and washed in HCl. It was measured as 59.2 emu/g at 15 kOe, which is higher than that of the pure sample (57.5 emu/g). Thus, the magnetic parameters are optimized in the sample Ba{sub 0.7}La{sub 0.3}Fe{sub 12}O{sub 19} so as to maximize both coercivity and specific saturation magnetization in the HCl-washed sample synthesized by starting with an unusually low Fe/(Ba+La) molar ratio of 2 (or n=1). - Research highlights: Effect of lanthanum substitution on the phase composition

  3. Solution based approaches for the morphology control of BaTiO3 particulates

    Directory of Open Access Journals (Sweden)

    Florentina Maxim

    2010-09-01

    Full Text Available Within the action COST 539 - ELENA our contribution was aimed at studying solution based approaches for the morphology control of BaTiO3 particulates. Initially, our kinetic analysis and systematic structural and morphological studies, demonstrated that during hydrothermal synthesis from layered titanate nanotubes (TiNTS, BaTiO3 forms via two mechanisms depending on the temperature and time. At low temperatures (90°C, “wild” type BaTiO3 dendritic particles with cubic structure were formed through a phase boundary topotactic reaction. At higher temperatures and/or for longer times time, the reaction is controlled by a dissolution precipitation mechanism and “seaweed” type BaTiO3 dendrites are formed. Our results unambiguously elucidated why TiNTs do not routinely act as templates for the formation of 1D BaTiO3.In our subsequent investigations, the effect of additives on the aqueous and hydrothermal synthesis of BaTiO3 was assessed. We reported that although the tested additives influenced the growth of BaTiO3, their behaviour varied; poly(acrylic acid (PAA adsorbed on specific crystallographic faces changing the growth kinetics and inducing the oriented attachment of the particles; poly(vinyl pyrrolidone (PVP, sodium dodecylsulfate (SDS and hydroxypropylmethylcellulose (HPMC act as growth inhibitors rather than crystal habit modifiers; and DFructose appeared to increase the activation energy for nucleation, resulting in small crystals (26 nm. Our work clearly indicates that the synthesis of 1D nanostructures of complex oxides by chemical methods is non trivial.

  4. Surfactant-assisted synthesis of mono-dispersed cubic BaTiO{sub 3} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hai, Chunxi [National Institute of Advanced Industrial Science and Technology (AIST), Shimo-Shidami, Moriyama-ku, Nagoya 463-8560 (Japan); Inukai, Koji; Takahashi, Yosuke [Noritake Co., Limited, RD Center, Miyoshi 470-0293 (Japan); Izu, Noriya; Akamatsu, Takafumi; Itoh, Toshio [National Institute of Advanced Industrial Science and Technology (AIST), Shimo-Shidami, Moriyama-ku, Nagoya 463-8560 (Japan); Shin, Woosuck, E-mail: w.shin@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), Shimo-Shidami, Moriyama-ku, Nagoya 463-8560 (Japan)

    2014-09-15

    Mono-dispersed BaTiO{sub 3} nanoparticles have been prepared via the assistance of capping agent poly(vinylpyrrolidone) (PVP). - Highlights: • BaTiO{sub 3} nanoparticles with single cubic crystal structure. • Poor dispersibility of nanoparticles has been overcome by in situ modification way. • Growth competition between BaTiO3 core and polymer shell. - Abstract: In this study, poly(vinylpyrrolidone)-assisted synthesis of mono-dispersed BaTiO{sub 3} nanoparticles have been reported. The various processing parameters, namely, refluxing temperature, KOH concentration, and poly(vinylpyrrolidone) concentration, have been varied, and the effects on the growth of BaTiO{sub 3} particles have been analyzed systematically. X-ray diffraction studies indicated that poly(vinylpyrrolidone) did not affect the crystal structure, but rather influenced the crystal lattice structure. In addition, the use of surfactant poly(vinylpyrrolidone) hindered the agglomeration of the nanoparticles, and facilitated the formation of mono-dispersed core–shell organic/inorganic hybrid nanocomposite. Furthermore, the mineralizer KOH promoted the dissolution of reactants and promoted the crystallization of BaTiO{sub 3} particles. Accordingly, the dissolution-precipitation scheme was believed to be the mechanism underlying the formation of BaTiO{sub 3} particles. This was further substantiated by the experimental observations, which indicated that the nucleation and crystallization of the particles was affected by the KOH concentration in the reaction system. Finally, the formation of mono-dispersed core–shell nanocomposites proceeded via reaction limited cluster aggregation. We believe that the method proposed in this study could be extended for the synthesis of mono-dispersed nanoparticles for industrial applications.

  5. Gibbs Free Energy of Formation of Eu 1+ yBa 2- yCu 3O 7- xand Related Phases in the Eu 2O 3-CuO-BaO System

    Science.gov (United States)

    Przybyło, W.; Onderka, B.; Fitzner, K.

    1996-10-01

    The Gibbs energies of formation of the ternary phases in the Eu-Ba-Cu-O system have been obtained from solid state electrochemical measurements in the temperature range 973 to 1173 K. Cells employing single-crystal calcium fluoride as an electrolyte were used in studies of CuBaO2, Eu2CuBaO5, and Eu1+yBa2-yCu3O7-x(y= 0, 0.5). Based on the results of emf measurements the standard Gibbs free energy of formation of respective phases from the constituent oxides was derived.

  6. Jumping the gun: Smoking constituent BaP causes premature primordial follicle activation and impairs oocyte fusibility through oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Sobinoff, A.P.; Pye, V. [Reproductive Science Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW2308 (Australia); Nixon, B.; Roman, S.D. [Reproductive Science Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW2308 (Australia); ARC Centre of Excellence in Biotechnology and Development, University of Newcastle, Callaghan, NSW2308 (Australia); McLaughlin, E.A., E-mail: eileen.mclaughlin@newcastle.edu.au [Reproductive Science Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW2308 (Australia); ARC Centre of Excellence in Biotechnology and Development, University of Newcastle, Callaghan, NSW2308 (Australia)

    2012-04-01

    Benzo(a)pyrene (BaP) is an ovotoxic constituent of cigarette smoke associated with pre-mature ovarian failure and decreased rates of conception in IVF patients. Although the overall effect of BaP on female fertility has been documented, the exact molecular mechanisms behind its ovotoxicity remain elusive. In this study we examined the effects of BaP exposure on the ovarian transcriptome, and observed the effects of in vivo exposure on oocyte dysfunction. Microarray analysis of BaP cultured neonatal ovaries revealed a complex mechanism of ovotoxicity involving a small cohort of genes associated with follicular growth, cell cycle progression, and cell death. Histomorphological and immunohistochemical analysis supported these results, with BaP exposure causing increased primordial follicle activation and developing follicle atresia in vitro and in vivo. Functional analysis of oocytes obtained from adult Swiss mice treated neonatally revealed significantly increased levels of mitochondrial ROS/lipid peroxidation, and severely reduced sperm-egg binding and fusion in both low (1.5 mg/kg/daily) and high (3 mg/kg/daily) dose treatments. Our results reveal a complex mechanism of BaP induced ovotoxicity involving developing follicle atresia and accelerated primordial follicle activation, and suggest short term neonatal BaP exposure causes mitochondrial leakage resulting in reduced oolemma fluidity and impaired fertilisation in adulthood. This study highlights BaP as a key compound which may be partially responsible for the documented effects of cigarette smoke on follicular development and sub-fertility. -- Highlights: ► BaP exposure up-regulates canonical pathways linked with follicular growth/atresia. ► BaP causes primordial follicle activation and developing follicle atresia. ► BaP causes oocyte mitochondrial ROS and lipid peroxidation, impairing fertilisation. ► Short term neonatal BaP exposure compromises adult oocyte quality.

  7. Phonons in mixed superionic fluorites (BaF2)1–x(LaF3)x

    Indian Academy of Sciences (India)

    Unknown

    BaF2)1–x(LaF3)x have been investigated by applying de .... The central force constant between Ba2+–Ba2+ ions is assumed to be the same as that between F1. – –F1. – or F2. – –F2. – ions and is repre- sented by α3. Here Ze is the charge on ...

  8. Structural, optical and electronic properties of K2Ba(NO3)4 crystal

    Science.gov (United States)

    Isaenko, L. I.; Korzhneva, K. E.; Goryainov, S. V.; Goloshumova, A. A.; Sheludyakova, L. A.; Bekenev, V. L.; Khyzhun, O. Y.

    2018-02-01

    Nitrate crystals reveal nonlinear optical properties and could be considered as converters of laser radiation in the short-wave region. The conditions for obtaining and basic properties of K2Ba(NO3)4 double nitrate crystals were investigated. Crystal growth was implemented by slow cooling in the temperature range of 72-49 °C and low rate evaporation. The structural analysis of K2Ba(NO3)4 formation on the basis of two mixed simple nitrate structures is discussed. The main groups of oscillations in K2Ba(NO3)4 crystal were revealed using Raman and IR spectroscopy, and the table of vibrations for this compound was compiled. The electronic structure of K2Ba(NO3)4 was elucidated in the present work from both experimental and theoretical viewpoints. In particular, X-ray photoelectron spectroscopy (XPS) was employed in the present work to measure binding energies of the atoms constituting the titled compound and its XPS valence-band spectrum for both pristine and Ar+ ion-bombarded surfaces. Further, total and partial densities of states of constituent atoms of K2Ba(NO3)4 have been calculated. The calculations reveal that the O 2p states dominate in the total valence-band region of K2Ba(NO3)4 except of its bottom, where K 3p and Ba 5p states are the principal contributors, while the bottom of the conduction band is composed mainly of the unoccupied O 2p states, with somewhat smaller contributions of the N 2p∗ states as well. With respect to the occupation of the valence band by the O 2p states, the present band-structure calculations are confirmed by comparison on a common energy scale of the XPS valence-band spectrum and the X-ray emission O Kα band for the K2Ba(NO3)4 crystal under study. Furthermore, the present calculations indicate that the K2Ba(NO3)4 compound is a direct-gap material.

  9. Synthesis and characterization of Ln,Yb:BaGdF5 (Ln = Er, Ho) nanocrystals by hydrothermal method

    Science.gov (United States)

    Hu, Hongliang; Xiao, Liguang; Zhang, Xuejian

    2017-10-01

    The Er,Yb: BaGdF5 and Ho,Yb: BaGdF5 nanocrystal materials with the narrow particle size distribution was synthesized by a hydrothermal method at 180°C for 24 h. The phase structure and fluorescence properties were investigated by X-ray diffraction, scanning electron microscopy and up-conversion spectroscopy, respectively. The phase composition does not change with increasing the pH value, leading to the formation of a pure phase BaGdF5, while the solution was turbid state. The products show a good crystallinity, dispersion and uniform particle size distribution. Under the LD excitation at 980 nm, Er,Yb: BaGdF5 and Ho,Yb: BaGdF5 nanocrystal materials were researched in the visible range of the fluorescence spectrum. Er,Yb: BaGdF5 nanocrystals were achieved the launch of green, blue, and red. Ho,Yb: BaGdF5 nanocrystal with green and red light output were realized. The light-emitting belong to the two-photon transition process. And the possible mechanism for the corresponding up-conversion luminescence was also discussed. The Er,Yb: BaGdF5 and Ho,Yb: BaYbF5 nanocrystals with the narrow particle size distribution have potential applications in biological field as luminescence probes.

  10. Evaluation of band offset at amorphous-Si/BaSi{sub 2} interfaces by hard x-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Takabe, Ryota; Takeuchi, Hiroki; Du, Weijie; Toko, Kaoru; Suemasu, Takashi [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Ito, Keita [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Japan Society for the Promotion of Science (JSPS), Chiyoda, Tokyo 102-0083 (Japan); Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Ueda, Shigenori [Synchrotron X-Ray Station at SPring-8, National Institute for Materials Science (NIMS), Sayo, Hyogo 679-5148 (Japan); Quantum Beam Unit, NIMS, Tsukuba, Ibaraki 305-0047 (Japan); Kimura, Akio [Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan)

    2016-04-28

    The 730 nm-thick undoped BaSi{sub 2} films capped with 5 nm-thick amorphous Si (a-Si) intended for solar cell applications were grown on Si(111) by molecular beam epitaxy. The valence band (VB) offset at the interface between the BaSi{sub 2} and the a-Si was measured by hard x-ray photoelectron spectroscopy to understand the carrier transport properties by the determination of the band offset at this heterointerface. We performed the depth-analysis by varying the take-off angle of photoelectrons as 15°, 30°, and 90° with respect to the sample surface to obtain the VB spectra of the BaSi{sub 2} and the a-Si separately. It was found that the barrier height of the a-Si for holes in the BaSi{sub 2} is approximately −0.2 eV, whereas the barrier height for electrons is approximately 0.6 eV. This result means that the holes generated in the BaSi{sub 2} layer under solar radiation could be selectively extracted through the a-Si/BaSi{sub 2} interface, promoting the carrier separation in the BaSi{sub 2} layer. We therefore conclude that the a-Si/BaSi{sub 2} interface is beneficial for BaSi{sub 2} solar cells.

  11. Formation of Ba bismuthate nanobelts and sensitive electrochemical determination of tartaric acid

    Science.gov (United States)

    Pei, L. Z.; Lin, F. F.; Qiu, F. L.; Wang, W. L.; Zhang, Y.; Fan, C. G.

    2017-07-01

    A facile hydrothermal route without additives was used to prepare novel Ba bismuthate nanobelts. The Ba bismuthate nanobelts were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM and electrochemical method. The obtained nanobelts are composed of single crystalline monoclinic BaBiO2.5 phase with the thickness, width and length of about 50 nm, 1 µm and several dozens of micrometers, respectively. The formation of the Ba bismuthate nanobelts is dependent on the temperature and reaction time. Electrochemical measurements display that the Ba bismuthate nanobelts modified glassy carbon electrode has good electrochemical activity toward tartaric acid. A pair of semi-reversible cyclic voltammetry (CV) peaks are observed at  -0.49 V and  +0.01 V, respectively. The peak current is linearly relative to the scan rate and tartaric acid concentration. The limit of detection (LOD) is 0.12 µM with the linear range of 0.001-2 mM. The work provides new electrode modified materials for the sensor to detect tartaric acid.

  12. Colossal dielectric constant of NaNbO3 doped BaTiO3 ceramics

    Directory of Open Access Journals (Sweden)

    Cao Wan Q.

    2016-06-01

    Full Text Available BaTiO3 ceramics doped with 0.40 mol% NaNbO3 were prepared using a traditional approach by sintering at temperature of 1250 °C to 1290 °C. The prepared ceramics was characterized by very good dielectric properties, such as high dielectric constant (1.5 × 105, low dielectric loss (0.1, and good dielectric temperature stability in the −40 °C to 100 °C range for the sample sintered below 1270 °C. The dielectric characteristics obtained with XPS confirmed that Ti4+ ions remain in the state without any change. The huge increase in dielectric constant in NaNbO3 doped BaTiO3 samples occurs when large amount of Ba2+ ions are excited to a high energy bound state of Ba2+ − e or Ba+ to create electron hopping conduction. For samples with the content of NaNbO3 higher than 0.40 mol%, or sintering temperature higher than 1280 °C, compensation effect is dominated by cation vacancies with sharply decreasing dielectric constant and increased dielectric loss. The polaron effect is used to explain the relevant mechanism of giant dielectric constant appearing in the ferroelectric phase.

  13. BaCu2Se2 based compounds as promising thermoelectric materials.

    Science.gov (United States)

    Li, Jing; Zhao, Li-Dong; Sui, Jiehe; Berardan, David; Cai, Wei; Dragoe, Nita

    2015-02-07

    In the past few years, many studies have been devoted to the thermoelectric properties of copper selenides and sulfides, and several families of materials have been developed with promising performances. In this paper, we report on the synthesis and thermoelectric properties of Na-doped BaCu2Se2 from 20 K to 773 K. By Na doping at the Ba site, the electrical conductivity can be increased by 2 orders of magnitude, and the power factor can reach 8.2 μW cm(-1) K(-2) at 773 K. Combined with a low thermal conductivity of 0.65 W m(-1) K(-1), a ZT of 1.0 has been obtained for Ba0.925Na0.075Cu2Se2 at 773 K, which is the highest value reported in this family to date. However, BaCu2Se2 volatilizes at 473 K, so a protective coating is necessary for its application. Besides, we studied the thermal expansion coefficient of BaCu2Se2 in this paper.

  14. Hybrid molecular beam epitaxy for the growth of stoichiometric BaSnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, Abhinav, E-mail: praka019@umn.edu; Dewey, John; Yun, Hwanhui; Jeong, Jong Seok; Mkhoyan, K. Andre; Jalan, Bharat, E-mail: bjalan@umn.edu [Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2015-11-15

    Owing to its high room-temperature electron mobility and wide bandgap, BaSnO{sub 3} has recently become of significant interest for potential room-temperature oxide electronics. A hybrid molecular beam epitaxy (MBE) approach for the growth of high-quality BaSnO{sub 3} films is developed in this work. This approach employs hexamethylditin as a chemical precursor for tin, an effusion cell for barium, and a radio frequency plasma source for oxygen. BaSnO{sub 3} films were thus grown on SrTiO{sub 3} (001) and LaAlO{sub 3} (001) substrates. Growth conditions for stoichiometric BaSnO{sub 3} were identified. Reflection high-energy electron diffraction (RHEED) intensity oscillations, characteristic of a layer-by-layer growth mode were observed. A critical thickness of ∼1 nm for strain relaxation was determined for films grown on SrTiO{sub 3} using in situ RHEED. Scanning transmission electron microscopy combined with electron energy-loss spectroscopy and energy dispersive x-ray spectroscopy confirmed the cube-on-cube epitaxy and composition. The importance of precursor chemistry is discussed in the context of the MBE growth of BaSnO{sub 3}.

  15. Tunability modelling and experiments for BaTiO3-based solid solutions

    Directory of Open Access Journals (Sweden)

    Lavinia-Petronela Curecheriu

    2007-12-01

    Full Text Available In this paper, the electric field dependence of the dielectric constant in some BaTiO3-based ferroelectrics is theoretically described by means of the Landau-Ginzburg-Devonshire (LGD theory and its’ approximations valid for low polarizations (Johnson’s equation and even-power relation when the sample is in its ferroelectric state and by a model considering random non-interacting dipolar units in a double well potential for the paraelectric state. High-voltage tunability data were obtained at room temperature for BaZr0.10Ti0.90O3 and Ba0.70Sr0.30TiO3 ceramics. The data were well fitted by using the Johnson’s approximation for the ferroelectric-relaxor BaZr0.10Ti0.90O3 and satisfactory for the Ba0.70Sr0.30TiO3 ceramics, close to its ferro-para phase transition. For the last one, the non-interacting dipolar units model allows to determine the average dipolar moment.

  16. Preparation and microwave-absorbing property of EP/BaFe12O19/PANI composites

    Science.gov (United States)

    Feng, Huixia; Bai, Dezhong; Tan, Lin; Chen, Nali; Wang, Yueyi

    2017-07-01

    In this paper, we introduced expanded perlite (EP) into the system of ferrite composites for the first time. By sol-gel self-propagating combustion method, expanded perlite/barium ferrite (EP/BaFe12O19) was prepared, and then ternary composites of expanded perlite/barium ferrite/polyaniline (EP/BaFe12O19/PANI) were obtained by in-situ oxidative polymerization of aniline on EP/BaFe12O19 mixture. Although, as is well known, the values of saturation magnetization (Ms), remnant magnetization (Mr) and coercivity (Hc) of composites are all lower than the pure BaFe12O19 particles owing to the existence of the nonmagnetic EP and PANI, the EP/BaFe12O19/PANI composites exhibit absorption characteristics at the range of 2-18 GHz, the effective absorption bandwidth (less than -4 dB) reached 12.12 GHz and the minimum reflection loss of -5.66 dB at 8.48 GHz with only 2 mm thickness of absorbing layer. So the composites could resist urban electromagnetic pollution, such as wireless network, communication and so on, effectively.

  17. Innovative treatment trains of bottom ash (BA) from municipal solid waste incineration (MSWI) in Germany.

    Science.gov (United States)

    Holm, Olaf; Simon, Franz-Georg

    2017-01-01

    The industrial sector of bottom ash (BA) treatment from municipal solid waste incineration (MSWI) in Germany is currently changing. In order to increase the recovery rates of metals or to achieve a higher quality of mineral aggregates derived from BA, new procedures have been either implemented to existing plants or completely new treatment plants have been built recently. Three treatment trains, which are designated as entire sequences of selected processing techniques of BA, are introduced and compared. One treatment train is mainly characterized by usage of a high speed rotation accelerator whereas another is operating completely without crushing. In the third treatment train the BA is processed wet directly after incineration. The consequences for recovered metal fractions and the constitution of remaining mineral aggregates are discussed in the context of legislative and economical frameworks. Today the recycling or disposal options of mineral residues still have a high influence on the configuration and the operation mode of the treatment trains of BA despite of the high value of recovered metals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Nearly massless Dirac fermions hosted by Sb square net in BaMnSb2.

    Science.gov (United States)

    Liu, Jinyu; Hu, Jin; Cao, Huibo; Zhu, Yanglin; Chuang, Alyssa; Graf, D; Adams, D J; Radmanesh, S M A; Spinu, L; Chiorescu, I; Mao, Zhiqiang

    2016-07-28

    Layered compounds AMnBi2 (A = Ca, Sr, Ba, or rare earth element) have been established as Dirac materials. Dirac electrons generated by the two-dimensional (2D) Bi square net in these materials are normally massive due to the presence of a spin-orbital coupling (SOC) induced gap at Dirac nodes. Here we report that the Sb square net in an isostructural compound BaMnSb2 can host nearly massless Dirac fermions. We observed strong Shubnikov-de Haas (SdH) oscillations in this material. From the analyses of the SdH oscillations, we find key signatures of Dirac fermions, including light effective mass (~0.052m0; m0, mass of free electron), high quantum mobility (1280 cm(2)V(-1)S(-1)) and a π Berry phase accumulated along cyclotron orbit. Compared with AMnBi2, BaMnSb2 also exhibits much more significant quasi two-dimensional (2D) electronic structure, with the out-of-plane transport showing nonmetallic conduction below 120 K and the ratio of the out-of-plane and in-plane resistivity reaching ~670. Additionally, BaMnSb2 also exhibits a G-type antiferromagnetic order below 283 K. The combination of nearly massless Dirac fermions on quasi-2D planes with a magnetic order makes BaMnSb2 an intriguing platform for seeking novel exotic phenomena of massless Dirac electrons.

  19. Impacts of Mining and Urbanization on the Qin-Ba Mountainous Environment, China

    Directory of Open Access Journals (Sweden)

    Xinliang Xu

    2016-05-01

    Full Text Available The Qin-Ba Ecological Functional Zone is a component of China’s ecological security pattern designed to protect the regional ecosystem and maintain biodiversity. However, due to the impact of mining and urban encroachment, the plight of a sustainable ecosystem in the Qin-Ba mountainous area is deteriorating. This paper has used a remote sensing and geographic information system (GIS to examine the impacts of mining and urban encroachment on the environment in the Qin-Ba mountainous area. The results indicate that the total mined area in 2013 was 22 km2 and is predicted to escalate. Results also show that the ecosystems in Fengxian County, Shaanxi Province and Baokang County, Hubei Province were most severely affected by mining. Urbanization in the Qin-Ba mountainous area has seen an increase of 85.58 km2 in urban land use from 2010 to 2013. In addition, infrastructure development including airport construction, tourism resorts and real estate development in the Qin-Ba mountainous area has intensified environmental and biodiversity disturbances since large areas of forest have been cleared. Our results should provide insight and assistance to city planners and government officials in making informed decisions.

  20. Colloidal synthesis of BaF2 nanoparticles and their application as fillers in polymer nanocomposites

    Science.gov (United States)

    Sathyamurthy, Srivatsan; Tuncer, Enis; More, Karren L.; Gu, Baohua; Sauers, Isidor; Paranthaman, M. Parans

    2012-03-01

    Nanoparticles of pure and Eu-doped BaF2 have been prepared through sol-gel colloidal synthesis. In addition, BaF2-filled PMMA polymer nanocomposites were fabricated and dielectric properties were measured. The as-synthesized pure and Eu-doped BaF2 nanoparticles were analyzed by both X-ray diffraction and transmission electron microscopy and consisted of crystalline BaF2 particles with an average diameter of 13.6 nm with a standard deviation of about ±2.4 nm. The photoluminescence properties of the pure and Eu-doped (2%, 4% and 8%) nanoparticles showed characteristic emission of Eu3+ (5D0→7F J ( J=1-4) transitions). We also measured significantly enhanced dielectric breakdown strength of up to 30% for BaF2 nanocomposites over the unfilled PMMA polymer. This study thus offers some promise of sol-gel synthesis of nanocomposite dielectrics with great potential for use as electrical insulation materials in cryogenic high-voltage applications.

  1. High-pressure electrical resistivity studies for Ba1-xCsxFe2Se3

    Science.gov (United States)

    Kawashima, C.; Soeda, H.; Takahashi, H.; Hawai, T.; Nambu, Y.; Sato, T. J.; Hirata, Y.; Ohgushi, K.

    2017-10-01

    High-pressure electrical resistance measurements were performed for iron-based ladder material Ba1-xCsxFe2Se3 (x = 0.25 and 0.65) using a diamond anvil cell (DAC). Recent high-pressure study revealed that iron-based ladder material BaFe2S3 exhibits an insulator-metal transition and superconductivity, and this discovery would provide important insight for understanding the mechanism of iron-based superconductors. Therefore, it is intriguing to investigate the high-pressure properties for the iron-based ladder material Ba1-xCsxFe2Se3 system. The parent compounds BaFe2Se3 and CsFe2Se3 show insulating and magnetic ordering features. For Ba1-xCsxFe2Se3 system, no magnetic ordering is observed for x = 0.25 and minimum charge gap was estimated for x = 0.65. The insulator-metal transitions are observed in both materials.

  2. Consequences of Ca multisite occupation for the conducting properties of BaTiO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Zulueta, Y.A., E-mail: yohandysalexis.zuluetaleyva@student.kuleuven.be [Departamento de Física, Facultad de Ciencias Naturales, Universidad de Oriente, CP-90500 Santiago de Cuba (Cuba); Department of Chemistry, KU Leuven, B-3001 Leuven (Belgium); Dawson, J.A. [Department of Engineering, University of Cambridge, Cambridge CB2 1PZ (United Kingdom); Leyet, Y. [Departamento de Engenharia de Materiais, Universidade Federal do Amazonas, Av. General Rodrigo Otávio, 6200 – Coroado I, 69077-000 Manaus (Brazil); Departamento de Física, Universidade Federal do Amazonas, Av. General Rodrigo Otávio, 6200 – Coroado I, 69077-000 Manaus, Amazonas (Brazil); Anglada-Rivera, J. [Instituto Federal de Educação Ciência e Tecnologia do Amazonas, Av. 7de Setembro, 1975, 69020-120 Manaus (Brazil); Guerrero, F. [Departamento de Física, Universidade Federal do Amazonas, Av. General Rodrigo Otávio, 6200 – Coroado I, 69077-000 Manaus, Amazonas (Brazil); Silva, R.S. [Departamento de Física, Universidade Federal de Sergipe, 49100-000 São Cristóvão, SE (Brazil); Nguyen, Minh Tho [Department of Chemistry, KU Leuven, B-3001 Leuven (Belgium)

    2016-11-15

    In combination with the dielectric modulus formalism and theoretical calculations, a newly developed defect incorporation mode, which is a combination of the standard A- and B-site doping mechanisms, is used to explain the conducting properties in 5 mol% Ca-doped BaTiO{sub 3}. Simulation results for Ca solution energies in the BaTiO{sub 3} lattice show that the new oxygen vacancy inducing mixed mode exhibits low defect energies. A reduction in dc conductivity compared with undoped BaTiO{sub 3} is witnessed for the incorporation of Ca. The conducting properties of 5 mol% Ca-doped BaTiO{sub 3} are analyzed using molecular dynamics and impedance spectroscopy. The ionic conductivity activation energies for each incorporation mode are calculated and good agreement with experimental data for oxygen migration is observed. The likely existence of the proposed defect configuration is also analyzed on the basis of these methods. - Graphical abstract: Oxygen vacancy formation as a result of self-compensation in Ca-doped BaTiO{sub 3}.

  3. Medication safety in pregnancy – Results from the MoBa study

    Directory of Open Access Journals (Sweden)

    Hedvig Nordeng

    2014-12-01

    Full Text Available This article summarizes the results of several of our studies on medication safety in pregnancy based on the Norwegian Mother and Child Cohort Study (MoBa. Medications investigated include antidepressants, NSAIDs, codeine, triptans, paracetamol and certain herbals. A major advantage of these studies is that MoBa has information on prescribed medications, over-the-counter medications and herbal medications. Moreover, MoBa enables the possibility of including a disease comparison group, and long-term follow-up into childhood. The size of MoBa enables designs like the sibling-design, which offers important advantages over studies comparing unrelated individuals. The possibility of linking MoBa to nationwide registries like the NorPD and the National Patient Registry enables validation of medication exposures and childhood diagnosis. Pharmacoepidemiological studies are vital to our understanding of the safety of medications in pregnancy, but great care must be taken in the analysis and interpretation of observational data to avoid problems of confounding and bias.

  4. Colloidal synthesis of BaF2 nanoparticles and their application as fillers in polymer nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Sathyamurthy, Srivatsan [ORNL; Tuncer, Enis [ORNL; More, Karren Leslie [ORNL; Gu, Baohua [ORNL; Sauers, Isidor [ORNL; Paranthaman, Mariappan Parans [ORNL

    2012-01-01

    Nanoparticles of pure and Eu-doped BaF2 have been prepared through sol-gel colloidal synthesis. In addition, BaF2 filled PMMA polymer nanocomposites were fabricated and dielectric properties were measured. The as-synthesized pure and Eu-doped BaF2 nanoparticles were analyzed by both X-ray diffraction and transmission electron microscopy and consisted of crystalline BaF2 particles with an average diameter of 13.6 nm with a standard deviation of about 2.4 nm. The photoluminescence properties of the pure and Eu-doped (2%, 4% and 8%) nanoparticles showed characteristic emission of Eu3+ (5D0 7FJ (J=1-4) transitions). We also measured significantly enhanced dielectric breakdown strength of up to 30% for BaF2 nanocomposites over the unfilled PMMA polymer. This study thus offers some promise of sol-gel synthesis of nanocomposite dielectrics with great potential for use as electrical insulation materials in cryogenic high voltage applications.

  5. Superconducting properties and microstructures for Ba2SmNbO6 and BaHfO3 co-doped SmBa2Cu3O y thin films

    Science.gov (United States)

    Kusafuka, Yuma; Ichino, Yusuke; Tsuchiya, Yuji; Ichinose, Ataru; Yoshida, Yuatka

    2017-12-01

    Recently, we observed that Ba2SmNbO6 (BSNO), which has a double perovskite structure, forms wide nanorods in a SmBa2Cu3O y (SmBCO) film when compared with BaHfO3 (BHO) nanorods. These wide nanorods can trap flux quanta effectively in low magnetic fields; on the other hand, narrow nanorods can trap flux quanta in high magnetic fields. In this paper, we doped SmBCO films with BSNO and BHO with the aim of introducing both wide and narrow nanorods and bringing out the flux pinning properties in low and high magnetic fields simultaneously. We investigated their microstructures and superconducting properties, and as a result, we confirmed that wide and narrow nanorods could coexist in the SmBCO films. The wide and narrow nanorods trapped the flux quanta in different magnetic fields. We also explored the optimal composition for BSNO + BHO co-doped SmBCO films. These findings indicate that flux pinning properties can be tuned by the multiple doping of BMO materials.

  6. Antiperovskite Chalco-Halides Ba3(FeS4)Cl, Ba3(FeS4)Br, and Ba3(FeSe4)Br with Spin Super-Super Exchange

    Science.gov (United States)

    Zhang, Xian; Liu, Kai; He, Jian-Qiao; Wu, Hui; Huang, Qing-Zhen; Lin, Jian-Hua; Lu, Zhong-Yi; Huang, Fu-Qiang

    2015-11-01

    Perovskite-related materials have received increasing attention for their broad applications in photovoltaic solar cells and information technology due to their unique electrical and magnetic properties. Here we report three new antiperovskite chalco-halides: Ba3(FeS4)Cl, Ba3(FeS4)Br, and Ba3(FeSe4)Br. All of them were found to be good solar light absorbers. Remarkably, although the shortest Fe-Fe distance exceeds 6 Å, an unexpected anti-ferromagnetic phase transition near 100 K was observed in their magnetic susceptibility measurement. The corresponding complex magnetic structures were resolved by neutron diffraction experiments as well as investigated by first-principles electronic structure calculations. The spin-spin coupling between two neighboring Fe atoms along the b axis, which is realized by the Fe-S···S-Fe super-super exchange mechanism, was found to be responsible for this magnetic phase transition.

  7. ISOLASI BAKTERI ASAM LAKTAT DARI KIMCHI DAN KEMAMPUANNYA MENGHASILKAN ZAT ANTI BAKTERI

    Directory of Open Access Journals (Sweden)

    Benedicta Yolanda Khristnaviera

    2017-09-01

    Full Text Available South Korea is famous for its fermented food called Kimchi, a traditional Korean food fermented from pickled vegetables with a mixture of spicy seasoning. Kimchi is now one of functional food products because of there are lactic acid bacteria that are probiotic and can produce bacteriocin compounds. These bacteriocin compounds may inhibit or have anti-bacterial activity. The purpose of this study was to obtain isolates of lactic acid bacteria from store-bought kimchi and homemade kimchi, to examine the antibacterial agent produced by lactic acid bacteria isolated from kimchi against Escherichia coli and Staphylococcus aureus bacteria. We conducted a Disk Diffusion Method to tests the bacteriocin activity, and data were descriptively analyzed. The results showed that eight isolates of lactic acid bacteria from store-bought kimchi and homemade kimchi homemade were able to inhibit the growth of tested bacteria, S. aureus and E. coli. Isolate D1 isolated from store-bought kimchi has largest inhibitory capability against S. aureus and E. coli; it has 16.00 mm and 17.33 mm inhibitory zone, respectively. Isolate B2 isolated from homemade kimchi has the most significant inhibitory ability against S. aureus and E. coli; it has 16.67 mm and 17.67 mm inhibitory zone, respectively. The lowest ability to form clear zone was found on isolate D2 isolated from homemade kimchi. The inhibitory zone of produce by strain D2 against S. aureus and E. coli were 7.67 mm and 8.67 mm, respectively.

  8. SKRINING DAN IDENTIFIKASI ISOLAT BAKTERI ENDOFIT UNTUK MENGENDALIKAN PENYAKIT HAWAR DAUN BAKTERI PADA BAWANG MERAH

    Directory of Open Access Journals (Sweden)

    Zurai Resti

    2014-08-01

    Full Text Available Screening and identification of endophytic bacteria to control bacterial leaf blight disease on Shallot. The experiment was conducted in Laboratory and Green House, from January to June 2012.   Laboratory experiment consisted of three steps:  (1 isolation of endophytic bacteria from healthy onion roots, (2In planta /screening of endophytic isolates capable of reducing bacterial leaf blight disease, and (3 molecular identification of potential endophytic isolates.  Treatments of  in planta test were arranged in Completely Randomized Design.  Collected isolates were tested for their capability in controlling bacterial leaf blight disease on shallot.  The variables observed were disease incidence, disease severity, and shallot yield. The results showed that out of 82 isolates successfully isolated, 56 isolates (68.29% were Gram positive, and 26 isolate (31.71% were Gram negative. All isolates were HR negative and pathogenicity negative. Six endophytic isolates showed  better performance in inducing resistance and increasing onion yield. Based on 16S rRNA sequence the six isolates were  Bacillus cereus strain P14 , Bacillus cereus strain Se07, Bacillus sp H1, Bacillus sp SJ1 and Serratia marcescens strain PPM4.

  9. AKTIVITAS ANTIBAKTERI KAIN KASA TERLAPISI TiO¬2/Ag AMORF, Ag, DAN KITOSAN/Ag TERHADAP BAKTERI GRAM NEGATIF DAN POSITIF (The Antibacterial Activity of Gauze Coated by Tio¬2/Ag Amorphous, Ag, and Chitosan/Ag Against Gram Negative and Positive Bacteria

    Directory of Open Access Journals (Sweden)

    Candra Purnawan

    2014-05-01

    Full Text Available ABSTRAK Pelapisan kain kasa dengan komposit TiO2/Ag amorf, kitosan/Ag, dan Ag telah dilakukan menggunakan metode dip coating dengan variasi urutan pelapisan. Komposit TiO2/Ag amorf disintesis dengan metode sol gel dalam pelarut etanol. Hasil sintesis dikarakterisasi menggunakan FTIR dan XRD. Kain kasa hasil pelapisan dikarakterisasi menggunakan XRD dan dilakukan uji antibakteri menggunakan metode optical density pada λ 600nm terhadap aktivitas bakteri Eschericia coli dan Stapylococcus aureus. Kain kasa dengan urutan pelapisan kitosan/Ag, komposit TiO2/Ag amorf, dan Ag memiliki daya antibakteri optimum. Daya antibakteri kain kasa terhadap E. coli sebesar 98, 66% setelah jam ke-24. Daya antibakteri tersebut lebih besar dibandingkan dengan daya antibakteri terhadap S. aureus yaitu 71,47% setelah jam ke-24.   ABSTRACT TiO2/Ag amorphous composite has been synthesized by sol gel method in ethanol. This composite  was characterized using FTIR and XRD. TiO2/Ag amorphous composite, chitosan/ Ag, and Ag coated in gauze using dip coating method with plating sequence variation. Coated gauze was characterized using XRD and antibacterial test was conducted by optical density at λ 600 nm against Escherichia coli and Staphylococcus aureus. The results showed that coated gauze with the sequence was chitosan/Ag, TiO2/Ag amorphous composite, and Ag was optimum antibacterial power. The inhibition against Escherichia coli was greater than Staphylococcus aureus. The inhibition against Escherichia coli was 98.66% for 24 hours and against Staphylococcus aureus was 71.47% for 24 hours.

  10. Simulation of iron impurity in BaTiO{sub 3} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Stashans, Arvids, E-mail: arvids@utpl.edu.e [Grupo de Fisicoquimica de Materiales, Instituto de Quimica Aplicada, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador); Castillo, Darwin [Grupo de Fisicoquimica de Materiales, Instituto de Quimica Aplicada, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador); Escuela de Electronica y Telecomunicaciones, Universidad Tecnica Particular de Loja, Apartado 11-01-608, Loja (Ecuador)

    2009-05-01

    Iron-doped barium titanate (BaTiO{sub 3}) has been simulated taking into account cubic and tetragonal crystallographic lattices of the crystal. A quantum-chemical method based on the Hartree-Fock formalism has been used throughout the study. The calculated equilibrium structures of Fe-doped crystals reveal the defect-inward displacements of the Ti and O atoms whereas the shifts for the Ba atoms are encountered to be away with respect to the Fe impurity. According to the analysis of electron density population and electron band structure it is found that some unusual chemical bonding might take place between the Fe atom and its six adjacent O atoms. The role of Fe impurity in the ferroelectric polarization of the tetragonal BaTiO{sub 3} crystal has been discussed too.

  11. Final Report BaBar Detector and Experimental at SLAC, September 30, 1998 - September 29, 1999

    CERN Document Server

    Judd, D J

    2000-01-01

    The Prairie View AandM University High Energy Physics Group with its contingent of three undergraduates physics majors, joined the BaBar Collaboration at SLAC in September 1994. BaBar is the experiment and detector running in the PEP-II ring at SLAC as part of the Asymmetric B Factory project there to study CP violation and heavy flavor physics. The focus of our effort before this year was with the Muon/Neutral Hadron Detector/Instrumented Flux Return (IFD) subgroup within the BaBar collaboration, and particularly with the GEANT simulation of the IFR-. With the GEANT3 simulation essentially FR-ozen, and the GEANT4 full simulation of the IFR- done, we have decided to redirect our efforts toward other areas.

  12. Superconductivity in the Tl-Ca-Ba-Cu-O System:. Synthesis, Characterization and Mechanism

    Science.gov (United States)

    Ganguli, A. K.; Swamy, K. S. Nanjunda; Subbanna, G. N.; Rajumon, M. K.; Sarma, D. D.; Rao, C. N. R.

    Synthesis and characterization of some of the members of the Tl-Ca-Ba-Cu-O system are presented. Tc in both the TlCan-1Ba2CunO2n+3 and Tl2Can-1Ba2CunO2n+4 series increase with the number of Cu-O layers, n; Tc in the latter series with two Tl-O layers are generally higher than in the former with a single Tl-O layer. Tl in the cuprates is in the 3+ state while Cu is in the 1+ and 2+ states, showing the importance of oxygen holes. The concentration of these holes seems to increase with the number of Tl-O layers.

  13. Growth and characterizations of Ba2Ti2Fe2As4O single crystals

    Directory of Open Access Journals (Sweden)

    Yun-Lei Sun, Abduweli Ablimit, Jin-Ke Bao, Hao Jiang, Jie Zhou and Guang-Han Cao

    2013-01-01

    Full Text Available Single crystals of a new iron-based superconductor Ba2Ti2Fe2As4O have been grown successfully via a Ba2As3-flux method in a sealed evacuated quartz tube. Bulk superconductivity with Tc ~ 21.5 K was demonstrated in resistivity and magnetic susceptibility measurements after the as-grown crystals were annealed at 500 °C in vacuum for a week. X-ray diffraction patterns confirm that the annealed and the as-grown crystals possess the identical crystallographic structure of Ba2Ti2Fe2As4O. Energy-dispersive x-ray spectra indicate that partial Ti/Fe substitution exists in the [Fe2As2] layers and the annealing process redistributes the Ti within the Fe-plane. The ordered Fe-plane stabilized by annealing exhibits superconductivity with magnetic vortex pinned by Ti.

  14. Structural and photocatalytic characterization of BaFe2O4 obtained at low temperatures

    Directory of Open Access Journals (Sweden)

    Silvana Da Dalt

    2011-12-01

    Full Text Available Barium monoferrite BaFe2O4 classified as permanent magnet stands out among other ceramic magnets due to its high chemical stability, corrosion resistance and low production cost. In addition, experiments conducted on photocatalytic degradation of methyl orange and UV transmittance by spectrophotometry have shown that this material has photocatalytic properties. The spinel ferrite is of importance in many technological areas such as computing, communications and security. Several techniques for synthesis have been studied to optimize the properties of this material. The synthesis of BaFe2O4 by conventional processes often occurs at temperatures above 1000 ºC. In this work, we obtained the phase BaFe2O4 at low temperatures (600 ºC from the combustion reaction using nitrates and maleic anhydride as metal complexing agent. Techniques of X-ray diffraction, specific surface area, thermogravimetry analysis and photocatalytic analysis were employed to characterize the products obtained.

  15. Synthesis and characterization of BaTiO{sub 3} nanoparticles in oxygen atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes, S., E-mail: sfuentes@ucn.c [Departamento de Quimica y Farmacia, Facultad de Ciencias, Universidad Catolica del Norte, Casilla 1280, Antofagasta (Chile); Center for the Development of Nanoscience and Nanotechnology, CEDENNA, Santiago (Chile); Zarate, R.A.; Chavez, E. [Departamento de Fisica, Facultad de Ciencias, Universidad Catolica del Norte, Casilla 1280, Antofagasta (Chile); Munoz, P. [Departamento de Quimica, Facultad de Ciencias, Universidad Catolica del Norte, Casilla 1280, Antofagasta (Chile); Center for the Development of Nanoscience and Nanotechnology, CEDENNA, Santiago (Chile); Ayala, M. [Departamento de Quimica, Facultad de Ciencias, Universidad Catolica del Norte, Casilla 1280, Antofagasta (Chile); Espinoza-Gonzalez, R. [Departamento de Ciencia de los Materiales, Facultad de Ciencias Fisicas y Matematicas, Universidad de Chile, Av. Tupper 2069, Santiago (Chile); Leyton, P. [Laboratorio de Fotofisica y Espectroscopia Molecular, Instituto de Quimica, Pontificia Universidad Catolica de Valparaiso, Av. Brasil 2950, Valparaiso (Chile)

    2010-09-03

    A new synthesis route to obtain high-purity barium titanate, BaTiO{sub 3}, using the sol-gel-hydrothermal reaction of TiCl{sub 4} and a BaCl{sub 2} solution in an oxygen atmosphere has been developed. The synthesized BaTiO{sub 3} nanoparticles are nearly spherical. Their grain sizes are determined by the reaction temperature, reaching values as low as 50 nm when the particles are synthesized at 200 {sup o}C; interestingly even those particles with the smallest grain sizes displayed a ferroelectric behavior as characterized by a polarization hysteresis loop. The microstructure and composition of the as-synthesized samples were investigated by X-ray diffraction (XRD), high-resolution TEM (HRTEM), Raman spectroscopy, atomic force microscopy (AFM) and energy-dispersive X-ray spectroscopy (EDS).

  16. Ziepniekkalna sasniedzamība izmantojot Rīgas sabiedrisko transportu

    OpenAIRE

    Šķiņķe, Katrīna

    2013-01-01

    Sasniedzamība ir būtisks sabiedriskā transporta un pilsētas sistēmas kvalitātes indikators. Bakalaura darbā „Ziepniekkalna sasniedzamība, izmantojot Rīgas sabiedrisko transportu” analizēta perifēro apkaimju sasniedzamība attiecībā pret centru, pārvietojoties ar sabiedrisko transportu, kā etalonteritoriju izmantojot Ziepniekkalna apkaimi. Bakalaura darba mērķis ir izvērtēt Rīgas sabiedriskā transporta tīkla struktūru no apkaimju sasniedzamības viedokļa un sniegt iespējamos risinājumus tās ...

  17. Effects of Ba doping on physical properties of La-Ca-Mn-O thin films

    CERN Document Server

    Hong, N H; Sakai, J; Iwasaki, H

    2003-01-01

    Transport and magnetic properties of La-Ba-Ca-Mn-O thin films fabricated by the pulsed laser deposition technique had been investigated systematically to see the effects of substitution of the small atom Ca by Ba which is much bigger. The induced insulator-to-metal (IM) transition was obtained not only in compositions near 0.5 and 0.18 which are boundaries between metallic and insulating phases but also in the heavily doped region. In the region of x > 0.5, the Ba doping causes an anomalous response of the system to the magnetic field and a positive magnetoresistance was observed. Besides, our results concerning the vicinity of 0.5 imply the existence of phase separation. As for x < 0.5, the doping enhances remarkably the paramagnetism-ferromagnetism transition and the IM transition temperatures.

  18. The role of electron correlations in the binding properties of Ca, Sr, and Ba

    Energy Technology Data Exchange (ETDEWEB)

    Belger, Dennis; Huesges, Zita; Voloshina, Elena; Paulus, Beate, E-mail: velena@chemie.fu-berlin.d [Institut fuer Chemie und Biochemie-Physikalische und Theoretische Chemie, Freie Universitaet Berlin, Takustrasse 3, 14195 Berlin (Germany)

    2010-07-14

    In order to apply wavefunction-based correlation methods to solids it is necessary to have reliable Hartree-Fock (HF) results for the infinite system of interest. We performed Hartree-Fock calculations for the group 2 heavy alkali-earth metals Ca, Sr, and Ba. For that, basis sets of valence-double-{zeta} quality have been optimized for the periodic systems. In all cases small-core pseudopotentials were used to deal with the scalar-relativistic effects. We determine the cohesive energies, the equilibrium volumes and the bulk moduli of the systems at the Hartree-Fock level and compare them with experimental data as well as the results of density functional theory calculations. Relativistic effects in the case of Ba are estimated by using a non-relativistic pseudopotential. The comparative HF versus the density functional theory (DFT) study of the electronic structures of Ca, Sr, and Ba has been performed.

  19. High-mobility BaSnO3 grown by oxide molecular beam epitaxy

    Directory of Open Access Journals (Sweden)

    Santosh Raghavan

    2016-01-01

    Full Text Available High-mobility perovskite BaSnO3 films are of significant interest as new wide bandgap semiconductors for power electronics, transparent conductors, and as high mobility channels for epitaxial integration with functional perovskites. Despite promising results for single crystals, high-mobility BaSnO3 films have been challenging to grow. Here, we demonstrate a modified oxide molecular beam epitaxy (MBE approach, which supplies pre-oxidized SnOx. This technique addresses issues in the MBE of ternary stannates related to volatile SnO formation and enables growth of epitaxial, stoichiometric BaSnO3. We demonstrate room temperature electron mobilities of 150 cm2 V−1 s−1 in films grown on PrScO3. The results open up a wide range of opportunities for future electronic devices.

  20. High-mobility BaSnO{sub 3} grown by oxide molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Raghavan, Santosh; Schumann, Timo; Kim, Honggyu; Zhang, Jack Y.; Cain, Tyler A.; Stemmer, Susanne, E-mail: stemmer@mrl.ucsb.edu [Materials Department, University of California, Santa Barbara, California 93106-5050 (United States)

    2016-01-01

    High-mobility perovskite BaSnO{sub 3} films are of significant interest as new wide bandgap semiconductors for power electronics, transparent conductors, and as high mobility channels for epitaxial integration with functional perovskites. Despite promising results for single crystals, high-mobility BaSnO{sub 3} films have been challenging to grow. Here, we demonstrate a modified oxide molecular beam epitaxy (MBE) approach, which supplies pre-oxidized SnO{sub x}. This technique addresses issues in the MBE of ternary stannates related to volatile SnO formation and enables growth of epitaxial, stoichiometric BaSnO{sub 3}. We demonstrate room temperature electron mobilities of 150 cm{sup 2} V{sup −1} s{sup −1} in films grown on PrScO{sub 3}. The results open up a wide range of opportunities for future electronic devices.

  1. BaTiO3-based piezoelectrics: Fundamentals, current status, and perspectives

    Science.gov (United States)

    Acosta, M.; Novak, N.; Rojas, V.; Patel, S.; Vaish, R.; Koruza, J.; Rossetti, G. A.; Rödel, J.

    2017-12-01

    We present a critical review that encompasses the fundamentals and state-of-the-art knowledge of barium titanate-based piezoelectrics. First, the essential crystallography, thermodynamic relations, and concepts necessary to understand piezoelectricity and ferroelectricity in barium titanate are discussed. Strategies to optimize piezoelectric properties through microstructure control and chemical modification are also introduced. Thereafter, we systematically review the synthesis, microstructure, and phase diagrams of barium titanate-based piezoelectrics and provide a detailed compilation of their functional and mechanical properties. The most salient materials treated include the (Ba,Ca)(Zr,Ti)O3, (Ba,Ca)(Sn,Ti)O3, and (Ba,Ca)(Hf,Ti)O3 solid solution systems. The technological relevance of barium titanate-based piezoelectrics is also discussed and some potential market indicators are outlined. Finally, perspectives on productive lines of future research and promising areas for the applications of these materials are presented.

  2. Structural study, photoluminescence, and photocatalytic activity of semiconducting BaZrO{sub 3}:Bi nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Borja-Urby, R. [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A.C., Leon, Gto 37150 (Mexico); Diaz-Torres, L.A., E-mail: ditlacio@cio.mx [Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados (EMANA), Centro de Investigaciones en Optica A.C., Leon, Gto 37150 (Mexico); Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro 76000 (Mexico); Moctezuma, E. [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, Av. Manuel Nava 6, San Luis Potosi, S.L.P., Mexico 78290 (Mexico); Vega, M. [Centro de Geociencias-UNAM, A.P. 1-1010, Queretaro 76000 (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Ciudad de Mexico, D.F. 07730 (Mexico)

    2011-10-25

    Wide band gap nanocrystalline bismuth doped barium zirconate is synthesized by a facile hydrothermal method at 100 deg. C. The obtained cubic perovskites are characterized by powder X-ray diffraction (XRD), UV-VIS diffuse reflectance spectroscopy, photoluminescence (PL) spectroscopy, and photocatalytic activity. The estimated band gap in the 2.4-4.9 eV range, depending on Bi concentration, suggests nanocrystalline BaZrO{sub 3}:Bi as a useful visible-light activated photocatalyst under excitation wavelengths <800 nm. Displacement of main XRD pattern peaks suggest that bismuth ion mostly substitutes into Zr{sup 4+} sites within the BaZrO{sub 3} host lattice. It is found that BaZrO{sub 3}:Bi decomposes methylene blue (MB) under both UV and visible light irradiation. The photocatalyst efficiency depends strongly on Bi content and induced defects.

  3. Using coral Ba/Ca records to investigate seasonal to decadal scale biogeochemical cycling in the surface and intermediate ocean.

    Science.gov (United States)

    LaVigne, M.; Cobb, K. M.; DeLong, K. L.; Freiberger, M. M.; Grottoli, A. G.; Hill, T. M.; Miller, H. R.; Nurhati, I. S.; Richey, J. N.; Serrato Marks, G.; Sherrell, R. M.

    2016-12-01

    Dissolved barium (BaSW), a bio-intermediate element, is linked to several biogeochemical processes such as the cycling and export of nutrients, organic carbon (Corg), and barite in surface and intermediate oceans. Dynamic BaSW cycling has been demonstrated in the water column on short timescales (days-weeks) while sedimentary records have documented geologic-scale changes in barite preservation driven by export production. Our understanding of how seasonal-decadal scale climate variability impacts these biogeochemical processes currently lacks robust records. Ba/Ca calibrations in surface and deep sea corals suggest barium is incorporated via cationic substitution in both aragonite and calcite. Here we demonstrate the utility of Ba/Ca for reconstructing biogeochemical variability using examples of surface and deep sea coral records. Century-long deep sea coral records from the California Current System (bamboo corals: 900-1500m) record interannual variations in Ba/Ca, likely reflecting changes in barite formation via bacterial Corg respiration or barite saturation state. A surface Porites coral Ba/Ca record from Christmas Island (central equatorial Pacific: 1978-1995) shows maxima during low productivity El Niño warm periods, suggesting that variations in BaSW are driven by biological removal via direct cellular uptake or indirectly via barite precipitation with the decomposition of large phytoplankton blooms at this location. Similarly, a sixteen-year long Siderastera siderea surface coral record from Dry Tortugas, FL (Gulf of Mexico: 1991-2007) shows seasonal Ba/Ca cycles that align with annual chlorophyll and δ13C. Taken together, these records demonstrate the linkages among Corg, nutrient cycling and BaSW in the surface and intermediate ocean on seasonal to decadal timescales. Multi-proxy paleoceanographic reconstructions including Ba/Ca have the potential to elucidate the mechanisms linking past climate, productivity, nutrients, and BaSW cycling in the past.

  4. Particle morphology as a control of permeation in polymer films obtained from MMA/nBA colloidal dispersions.

    Science.gov (United States)

    Lestage, David J; Urban, Marek W

    2004-07-20

    The combination of precision-controlled weight loss measurements and spectroscopic surface FT-IR analysis allowed us to identify unique behaviors of poly(methyl methacrylate) (p-MMA). When MMA and n-butyl acrylate (nBA) are polymerized into p-MMA and p-nBA homopolymer blends, MMA/nBA random copolymers, and p-MMA/p-nBA core-shell morphologies, a controlled mobility and stratification of low molecular weight components occurs in films formed from coalesced colloidal dispersions. Due to different affinities toward water, p-MMA and p-nBA are capable of releasing water at different rates, depending upon particle morphological features of initial dispersions. As coalescence progresses, water molecules are released from the high free volume p-nBA particles, whereas p-MMA retains water molecules for the longest time due to its hydrophilic nature. As a result, water losses at extended coalescence times are relatively small for p-MMA. MMA/nBA copolymer and p-MMA/p-nBA blends follow the same trends, although the magnitudes of changes are not as pronounced. The p-MMA/p-nBA core-shell behavior resembles that of p-nBA homopolymer, which is attributed to significantly lower content of the p-MMA component in particles. Annealing of coalesced colloidal films at elevated temperatures causes migration of SDOSS to the F-A interface, but for films containing primarily p-nBA, reverse diffusion back into the bulk is observed. These studies illustrate that the combination of different particle morphologies and temperatures leads to controllable permeation processes through polymeric films. Copyright 2004 American Chemical Society

  5. Factors influencing formation of highly dispersed BaTiO3 nanospheres with uniform sizes in static hydrothermal synthesis

    Science.gov (United States)

    Gao, Jiabing; Shi, Haiyue; Dong, Huina; Zhang, Rui; Chen, Deliang

    2015-07-01

    Highly dispersed BaTiO3 nanospheres with uniform sizes have important applications in micro/nanoscale functional devices. To achieve well-dispersed spherical BaTiO3 nanocrystals, we carried out as reported in this paper the systematic investigation on the factors that influence the formation of BaTiO3 nanospheres by the static hydrothermal process, including the NaOH concentrations [NaOH], molar Ba/Ti ratios ( R Ba/Ti), hydrothermal temperatures, and durations, with an emphasis on understanding the related mechanisms. Barium nitrate and TiO2 sols derived from tetrabutyl titanate were used as the starting materials. The as-synthesized BaTiO3 samples were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray analysis, thermogravimetry, differential thermal analysis, and FT-IR spectra. The highly dispersed BaTiO3 nanospheres (76 ± 13 nm) were achieved under the optimum hydrothermal conditions at 200 °C for 10 h: [NaOH] = 2.0 mol L-1 and R Ba/Ti = 1.5. Higher NaOH concentrations, higher Ba/Ti ratios, higher hydrothermal temperatures, and longer hydrothermal durations are favorable in forming BaTiO3 nanospheres with larger fractions of tetragonal phase and higher yields; but too long hydrothermal durations resulted in abnormal growth and reduced the uniformity in particle sizes. The possible formation mechanisms for BaTiO3 nanocrystals under the static hydrothermal conditions were investigated.

  6. Diamagnetic vortex barrier stripes in underdoped BaFe2(As1-xPx) 2

    Science.gov (United States)

    Yagil, A.; Lamhot, Y.; Almoalem, A.; Kasahara, S.; Watashige, T.; Shibauchi, T.; Matsuda, Y.; Auslaender, O. M.

    2016-08-01

    We report magnetic force microscopy (MFM) measurements on underdoped BaFe2(As1 -xPx)2 (x =0.26 ) that show enhanced superconductivity along stripes parallel to twin boundaries. These stripes of enhanced diamagnetic response repel superconducting vortices and act as barriers for them to cross. The width of the stripes is hundreds of nanometers, on the scale of the penetration depth, well within the inherent spatial resolution of MFM and implying that the width is set by the interaction of the superconductor with the MFM's magnetic tip. Unlike similar stripes observed previously by scanning SQUID in the electron doped Ba (Fe1 -xCox)2As2 , the stripes in the isovalently doped BaFe2(As1 -xPx)2 disappear gradually when we warm the sample towards the superconducting transition temperature. Moreover, we find that the stripes move well below the reported structural transition temperature in BaFe2(As1 -xPx)2 and that they can be much denser than in the Ba (Fe1 -xCox)2As2 study. When we cool in finite magnetic field we find that some vortices appear in the middle of stripes, suggesting that the stripes may have an inner structure, which we cannot resolve. Finally, we use both vortex decoration at higher magnetic field and deliberate vortex dragging by the MFM magnetic tip to obtain bounds on the strength of the interaction between the stripes and vortices. We find that this interaction is strong enough to play a significant role in determining the critical current in underdoped BaFe2(As1 -xPx)2 .

  7. Emergence of the sub-THz central peak at phase transitions in artificial BaTiO{sub 3}/(Ba,Sr)TiO{sub 3} superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Tikhonov, Yu.A.; Razumnaya, A.G.; Torgashev, V.I.; Zakharchenko, I.N.; Yuzyuk, Yu.I. [Faculty of Physics, Southern Federal University, Rostov-on-Don (Russian Federation); El Marssi, M. [Laboratoire de Physique de la Matiere Condensee, Universite de Picardie Jules Verne, Amiens (France); Ortega, N.; Kumar, A.; Katiyar, R.S. [Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, San Juan, PR (United States)

    2015-01-01

    A prominent central peak in the sub-THz frequency range was observed in the Raman spectra of BaTiO{sub 3}/(Ba,Sr)TiO{sub 3} (BT/BST) superlattice grown on (001)MgO substrate. Both soft and central mode show an anomaly around 200 K and 280 K, which can be correlated with orthorhombic to monoclinic phase transition of BST and BT, respectively. The observed temperature dependence of the central mode enabled us to explain rather broad temperature dependence of the dielectric permittivity previously observed in BT/BST superlattices. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Conductor-backed coplanar waveguide resonators of Y-Ba-Cu-O and Tl-Ba-Ca-Cu-O on LaAlO3

    Science.gov (United States)

    Miranda, F. A.; Bhasin, K. B.; Stan, M. A.; Kong, K. S.; Itoh, T.

    1992-01-01

    Conductor-backed coplanar waveguide (CBCPW) resonators operating at 10.8 GHz have been fabricated from Tl-Ba-Ca-O (TBCCO) and Y-Ba-Cu-O (YBCO) thin films on LaAlO3. The resonators consist of a coplanar waveguide (CPW) patterned on the superconducting film side of the LaAlO3 substrate with a gold ground plane coated on the opposite side. These resonators were tested in the temperature range from 14 to 106 K. At 77 K, the best of our TBCCO and YBCO resonators have an unloaded quality factor (Qo) 7 and 4 times, respectively, larger than that of a similar all-gold resonator. In this study, the Qo's of the TBCCO resonators were larger than those of their YBCO counterparts throughout the aforementioned temperature range.

  9. Conductor-backed coplanar waveguide resonators of Y-Ba-Cu-O and Tl-Ba-Ca-Cu-O on LaAlO[sub 3

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, F.A.; Bhasin, K.B.; Stan, M.A.; Kong, K.S.; Itoh, T.

    1992-10-01

    Conductor-backed coplanar waveguide (CBCPW) resonators operating at 10.8 GHz have been fabricated from Tl-Ba-Ca-O (TBCCO) and Y-Ba-Cu-O (YBCO) thin films on LaAlO[sub 3]. The resonators consist of a coplanar waveguide (CPW) patterned on the superconducting film side of the LaAlO3 substrate with a gold ground plane coated on the opposite side. These resonators were tested in the temperature range from 14 to 106 K. At 77 K, the best of our TBCCO and YBCO resonators have an unloaded quality factor (Qo) 7 and 4 times, respectively, larger than that of a similar all-gold resonator. In this study, the Qo's of the TBCCO resonators were larger than those of their YBCO counterparts throughout the aforementioned temperature range.

  10. Conduction Mechanisms in Multiferroic Multilayer BaTiO3/NiFe2O4/BaTiO3 Memristors

    Science.gov (United States)

    Samardzic, N.; Bajac, B.; Srdic, V. V.; Stojanovic, G. M.

    2017-10-01

    Memristive devices and materials are extensively studied as they offer diverse properties and applications in digital, analog and bio-inspired circuits. In this paper, we present an important class of memristors, multiferroic memristors, which are composed of multiferroic multilayer BaTiO3/NiFe2O4/BaTiO3 thin films, fabricated by a spin-coating deposition technique on platinized Si wafers. This cost-effective device shows symmetric and reproducible current-voltage characteristics for the actuating voltage amplitude of ±10 V. The origin of the conduction mechanism was investigated by measuring the electrical response in different voltage and temperature conditions. The results indicate the existence of two mechanisms: thermionic emission and Fowler-Nordheim tunnelling, which alternate with actuating voltage amplitude and operating temperature.

  11. Crystal structure and polarization hysteresis properties of ferroelectric BaTiO3 thin-film capacitors on (Ba,Sr)TiO3-buffered substrates

    Science.gov (United States)

    Maki, Hisashi; Noguchi, Yuji; Kutsuna, Kazutoshi; Matsuo, Hiroki; Kitanaka, Yuuki; Miyayama, Masaru

    2016-10-01

    Ferroelectric BaTiO3 (BT) thin-film capacitors with a buffer layer of (Ba1- x Sr x )TiO3 (BST) have been fabricated on (001) SrTiO3 (STO) single-crystal substrates by a pulsed laser deposition method, and the crystal structure and polarization hysteresis properties have been investigated. X-ray diffraction reciprocal space mapping shows that the BST buffer effectively reduces the misfit strain relaxation of the BT films on SrRuO3 (SRO) electrodes. The BT capacitor with the SRO electrodes on the BST (x = 0.3) buffer exhibits a well-saturated hysteresis loop with a remanent polarization of 29 µC/cm2. The hysteresis loop displays a shift toward a specific field direction, which is suggested to stem from the flexoelectric coupling between the out-of-plane polarization and the strain gradient adjacent to the bottom interface.

  12. Influence of BaO in perovskite electrodes for the electrochemical reduction of NOx

    DEFF Research Database (Denmark)

    Simonsen, Vibe Louise Ernlund; Johnsen, M.M.; Kammer Hansen, Kent

    2007-01-01

    Using the point electrode method, the effect of BaO on electrochemical reduction of NO (x) was investigated using the perovskites La0.85Sr0.15MnO3 (LSM15) and La0.85Sr0.15CoO3 (LSCo15) as electrode materials. The experiments were carried out in the temperature range 400-600 degrees C in 1% NO and...... favored oxygen reduction compared to reduction of nitric oxide. The LSCO15 electrode containing BaO reacted to form a K2NiF4-structure and was not tested further....

  13. Partial Melting of Solution-Spun Y1Ba2Cu3Ox Filament

    Science.gov (United States)

    Goto, Tomoko; Sugishita, Takaaki

    1991-06-01

    A partial-melt growth process is used to enhance the Jc of solution-spun Y1Ba2Cu3Ox filaments. The filaments have been prepared by dry spinning through a homogeneous aqueous solution containing mixed acetates of Y, Ba and Cu, polyvinyl alcohol, and organic acids. By controlling the melt growth process of the filaments, dense and highly oriented textures are produced, and a transport critical current density of more than 1× 104 A/cm2 at 77 K and 0 T is achieved for the filaments, each with a diameter of 60 μm.

  14. Ab initio study of double perovskites Ba2DySbO6

    Science.gov (United States)

    Jha, Dhiraj Kumar; Mandal, Golak; Ray, Chandan; Himanshu, A. K.; Singh, B. K.; Kumar, Uday; Choudhary, B. K.

    2016-05-01

    First principle study of the electronic band structure of Ba2DySbO6 synthesied by the solid state reaction technique have been performed within the framework of density function theory using WIEN2K. It has been shown in the absence of electron-electron interaction (U=0), BaDySO6 behaves like a half-metal. Even in the presence of DFT+U, electron-electron interaction via the Hubbard term (from U = 0, 2.72e -7.02eV), it still shows half metals.

  15. Ab initio study of double perovskites Ba{sub 2}DySbO{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Jha, Dhiraj Kumar; Mandal, Golak; Singh, B. K. [Department of Physics, T.M. Bhagalpur University, Bhagalpur, Bihar 812007 (India); Ray, Chandan [Department of Applied Physics & Ballistics, F. M. University, Balasore, Odisha, 756019 (India); Himanshu, A. K., E-mail: akh@vecc.gov.in [Nanostructured & Advanced Material Laboratory, Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Saltlake, Kolkata-700064 (India); Kumar, Uday [Department of Physical Sciences, IISER Kolkata, Mohanpur Campus, Mohanpur, West Bengal (India); Choudhary, B. K. [Department of Physics, Ranchi University, Jharkhand-834001 (India)

    2016-05-23

    First principle study of the electronic band structure of Ba2DySbO{sub 6} synthesied by the solid state reaction technique have been performed within the framework of density function theory using WIEN2K. It has been shown in the absence of electron-electron interaction (U=0), BaDySO{sub 6} behaves like a half-metal. Even in the presence of DFT+U, electron-electron interaction via the Hubbard term (from U = 0, 2.72e -7.02 eV), it still shows half metals.

  16. Energy Calibration of the BaBar EMC Using the Pi0 Invariant Mass Method

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, David J.; /Manchester U.

    2007-04-06

    The BaBar electromagnetic calorimeter energy calibration method was compared with the local and global peak iteration procedures, of Crystal Barrel and CLEO-II. An investigation was made of the possibility of {Upsilon}(4S) background reduction which could lead to increased statistics over a shorter time interval, for efficient calibration runs. The BaBar software package was used with unreconstructed data to study the energy response of the calorimeter, by utilizing the {pi}{sup 0} mass constraint on pairs of photon clusters.

  17. The luminescence of BaF{sub 2} nanoparticles upon high-energy excitation

    Energy Technology Data Exchange (ETDEWEB)

    Vistovskyy, V. V., E-mail: visvv@gmail.com; Zhyshkovych, A. V.; Halyatkin, O. O.; Voloshinovskii, A. S. [Ivan Franko National University of Lviv, 8a Kyryla i Mefodiya St., 79005 Lviv (Ukraine); Mitina, N. E.; Zaichenko, A. S. [Lviv Polytechnic National University, 12 S. Bandera St., 79013 Lviv (Ukraine); Rodnyi, P. A. [Saint-Petersburg State Polytechnical University, 29, Polytekhnicheskaya, 195251 Saint-Petersburg (Russian Federation); Vasil' ev, A. N. [Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Gektin, A. V. [Institute for Scintillation Materials, NAS of Ukraine, 60 Lenina Ave, 61001 Kharkiv (Ukraine)

    2014-08-07

    The dependence of X-ray excited luminescence intensity on BaF{sub 2} nanoparticle size was studied. A sharp decrease of self-trapped exciton luminescence intensity was observed when the nanoparticle size is less than 80 nm. The main mechanism of the luminescence quenching is caused by the escape of electrons from the nanoparticles. Escape of electrons from nanoparticles is confirmed by the considerable increase of luminescence intensity of the polystyrene scintillator with embedded BaF{sub 2} nanoparticles comparing with pure polystyrene scintillator.

  18. Sequential structural and antiferromagnetic transitions in BaFe2Se3 under pressure

    Science.gov (United States)

    Zhang, Yang; Lin, Ling-Fang; Zhang, Jun-Jie; Dagotto, Elbio; Dong, Shuai

    2018-01-01

    The discovery of superconductivity in the two-leg ladder compound BaFe2S3 has established the 123-type iron chalcogenides as a novel and interesting subgroup of the iron-based superconductor family. However, in this 123 series, BaFe2Se3 is an exceptional member, with a magnetic order and crystalline structure different from all others. Recently, an exciting experiment reported the emergence of superconductivity in BaFe2Se3 at high pressure [J. Ying et al., Phys. Rev. B 95, 241109(R) (2017), 10.1103/PhysRevB.95.241109]. In this paper, we report a first-principles study of BaFe2Se3 . Our analysis unveils a variety of qualitative differences between BaFe2S3 and BaFe2Se3 , including in the latter an unexpected chain of transitions with increasing pressure. First, by gradually reducing the tilting angle of iron ladders, the crystalline structure smoothly transforms from P n m a to C m c m at ˜6 GPa. Second, the system becomes metallic at 10.4 GPa. Third, its unique ambient-pressure Block antiferromagnetic ground state is replaced by the more common stripe (so-called CX-type) antiferromagnetic order at ˜12 GPa, the same magnetic state as the 123-S ladder. This transition is found at a pressure very similar to the experimental superconducting transition. Finally, all magnetic moments vanish at 30 GPa. This reported theoretical diagram of the complete phase evolution is important because of the technical challenges to capture many physical properties in high-pressure experiments. The information obtained in our calculations suggests different characteristics for superconductivity in BaFe2Se3 and BaFe2S3 : in 123-S pairing occurs when magnetic moments vanish, while in 123-Se the transition region from Block- to CX-type magnetism appears to catalyze superconductivity. Finally, an additional superconducting dome above ˜30 GPa is expected to occur.

  19. Operational Aspects of Dealing with the Large BaBar Data Set

    Energy Technology Data Exchange (ETDEWEB)

    Trunov, Artem G

    2003-06-13

    To date, the BaBar experiment has stored over 0.7PB of data in an Objectivity/DB database. Approximately half this data-set comprises simulated data of which more than 70% has been produced at more than 20 collaborating institutes outside of SLAC. The operational aspects of managing such a large data set and providing access to the physicists in a timely manner is a challenging and complex problem. We describe the operational aspects of managing such a large distributed data-set as well as importing and exporting data from geographically spread BaBar collaborators. We also describe problems common to dealing with such large datasets.

  20. Crystal growth of Ba 3BP 3O 12 with BPO 4-NaF flux

    Science.gov (United States)

    Zhang, Zhi-Jun; Wang, Hong; Hu, Guan-Qin; Chen, Hao-Hong; Yang, Xin-Xin; Zhao, Jing-Tai

    2010-04-01

    Single crystals of Ba 3BP 3O 12 with size of 10×8×2 mm 3 have been grown by the top-seeded solution growth (TSSG) method using BPO 4-NaF mixture as the flux. The crystals were characterized by X-ray powder diffraction, field emission scanning electron microscopy (FE-SEM) and transmittance spectrum. Ba 3BP 3O 12 single crystal exhibits wide transparency in the range 250-800 nm. The preparation process of starting materials and the effect of flux on the crystal growth were discussed.

  1. Redox reactions and mechanism of luminescence in BaFCl:Eu

    CERN Document Server

    Upadeo, S V; Gundurao, T K

    1998-01-01

    The phenomenon of stimulable luminescence of phosphors pre-irradiated with high-energy radiation is widely used in the field of imaging. Phosphors such as BaFX:Eu (X = Cl, Br) are extensively used in x-ray screens for digital image processing. There is, however, divided opinion regarding the mechanism responsible for the luminescence process in these materials. In this paper we have discussed the role of Eu sup 3 sup +reversible Eu sup 2 sup + conversion in BaFCl:Eu phosphor using PL, TL, TL emission and ESR techniques. (author)

  2. Thermal Hall Effect in a Phonon-Glass Ba3 CuSb2 O9

    Science.gov (United States)

    Sugii, K.; Shimozawa, M.; Watanabe, D.; Suzuki, Y.; Halim, M.; Kimata, M.; Matsumoto, Y.; Nakatsuji, S.; Yamashita, M.

    2017-04-01

    A distinct thermal Hall signal is observed in a quantum spin liquid candidate Ba3 CuSb2 O9 . The transverse thermal conductivity shows a power-law temperature dependence below 50 K, where a spin gap opens. We suggest that because of the very low longitudinal thermal conductivity and the thermal Hall signals, a phonon Hall effect is induced by strong phonon scattering of orphan Cu2 + spins formed in the random domains of the Cu2 + -Sb5 + dumbbells in Ba3 CuSb2 O9 .

  3. Internal conversion coefficients in Cs134, Ba137, and La139: A precise test of theory

    Science.gov (United States)

    Nica, N.; Hardy, J. C.; Iacob, V. E.; Balonek, C.; Trzhaskovskaya, M. B.

    2008-03-01

    Recently we measured the ratio of K-shell internal conversion coefficients, αK, for the 127.5-keV E3 transition in Cs134 and the 661.7-keV M4 transition in Ba137. We here report a measurement of the 165.9-keV M1 transition in La139, based on which we convert our earlier ratio measurement into individual αK values for the transitions in Cs134 and Ba137. These results continue to confirm the Dirac-Fock calculations of internal conversion coefficients that incorporate the atomic K-shell vacancy.

  4. Vigilancia sanitaria de cianobacterias en aguas de consumo humano y aguas de baño

    Directory of Open Access Journals (Sweden)

    Guadalupe Martínez Juárez

    2008-06-01

    Full Text Available Las autoridades de Salud Pública tienen implantados y consolidados programas de vigilancia sanitaria de aguas de consumo humano y aguas de baño, cuya finalidad es evitar riesgos para la salud de la población que consume agua o que utiliza con fines recreativos zonas de baño continentales. A la luz de los conocimientos científicos actuales, la proliferación de cianobacterias es un nuevo riesgo, que es necesario tener en cuenta en los programas de protección de la salud. En el presente trabajo, cuyo principal objetivo es conocer la presencia de cianobacterias y microcistinas en aguas utilizadas para consumo humano y baño, se muestran los resultados obtenidos en los programas de vigilancia llevados a cabo en el Área de Salud de Talavera de la Reina en los últimos cuatro años. Se ha realizado un estudio descriptivo de la presencia de cianobacterias y microcistinas, en agua bruta de la captación de dos embalses y en agua tratada a la salida de dos plantas de tratamiento de agua potable. Esto mismo se ha estudiado en otros dos embalses utilizados para baño en época estival. Para ello se han efectuado muestreos quincenales y posterior identificación y recuento de cianobacterias y determinación de microcistinas disueltas en agua mediante técnica ELISA.De los resultados de la vigilancia de aguas de consumo humano, se concluye que los valores de microcistinas detectados en los embalses no son elevados, apareciendo en menos del 6% de los muestreos efectuados y que el tratamiento aplicado en las plantas de tratamiento de agua potable, es eficaz para su eliminación. De la vigilancia de cianobacterias en el agua de baño, se concluye que a lo largo de tres temporadas, en el 48% de los muestreos realizados en las dos zonas de baño del área, se han superado las 100.000 células/ml, valor guía dado por la OMS, para valorar probabilidad moderada de efectos adversos en bañistas.Destacar que es necesario disponer de datos sobre exposición a

  5. The Norwegian Mother and Child Cohort Study (MoBa – new research possibilities

    Directory of Open Access Journals (Sweden)

    Per Magnus

    2007-01-01

    Full Text Available The Norwegian Mother and Child Cohort Study (MoBa is an observational, prospective study of up to 100 000 families. The study aims to find causes of diseases, with a focus on the interplay between early exposures and genetic factors. The collection of possible exposures starts in pregnancy. As of September 2007, about 80 000 families participate. A series of subprojects are ongoing, and analyses and publications are on their way. This paper presents the present situation of MoBa, and highlights new challenges and opportunities.

  6. The Norwegian Mother and Child Cohort Study (MoBa – new research possibilities

    Directory of Open Access Journals (Sweden)

    Per Magnus

    2009-10-01

    Full Text Available The Norwegian Mother and Child Cohort Study (MoBa is an observational, prospective study of up to 100 000 families. The study aims to find causes of diseases, with a focus on the interplay between early exposures and genetic factors. The collection of possible exposures starts in pregnancy. As of September 2007, about 80 000 families participate. A series of subprojects are ongoing, and analyses and publications are on their way. This paper presents the present situation of MoBa, and highlights new challenges and opportunities.

  7. One-step synthesis and enhanced luminescence of Eu-doped BaF2 nanocubes.

    Science.gov (United States)

    Liu, Ning; Zhao, Dan; Zhang, Daisheng; Wang, Lili; Qin, Weiping

    2011-11-01

    Europium (Eu3+) doped BaF2 nanocubes were synthesized successfully by a simple method, using oleic acid (OA) as a capping agent. The structure properties were characterized by XRD, FE-SEM, and FTIR. FE-SEM analysis indicates that the prepared nanomaterials have nanocubic morphology with a side length about 150 nm and can be controlled well by adjusting OA concentration. Moreover, the photoluminescence spectra of the samples were investigated. The emission intensity of the BaF2:Eu3+ nanocubes have been enhanced greatly after modified with proper amount of OA, which is promising for new applications and optical devices.

  8. Instability of the local environment of Mn2+ in BaF2

    Science.gov (United States)

    Shcherbakov, V. D.

    2017-05-01

    Excitation and luminescence spectra and luminescence lifetime of Mn2+ ion in BaF2 crystals at 77 K have been investigated for the first time. Mn2+ ions in the crystal are coordinated by six and eight fluorine ions, have a trigonal environment, and form exchange-coupled pairs. Several types of centers of the Mn2+ ion are formed mainly because of the large difference in the Mn2+ and Ba2+ ionic radii, which causes instability of the local structure around the activator and its strain, and exchange striction. An increase in the impurity concentration enhances these factors, thus changing the relative concentration of various centers.

  9. Core structures of {110} edge dislocations in BaTiO3

    Directory of Open Access Journals (Sweden)

    Yueliang Li

    2015-07-01

    Full Text Available The core structures of two types of {110} edge dislocations in BaTiO3 have been observed and investigated at the atomic scale by using aberration-corrected transmission electron microscopy (AC-TEM. The edge dislocations are both dissociated into two collinear partial edge dislocations bounding a complex stacking fault (SF. While the partial dislocations have the same Burgers vector, 1 2 [ 001 ] , the dissociation planes are different for the two types of edge dislocations, with one at the BaO plane and the other at the TiO2 plane. The SF energy has been estimated by measuring the SF width.

  10. Standardization of 137mCs+137mBa by Liquid Scintillation; Calibracion de 137Cs+137mBa por Centelleo Liquido

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, L.; Los Arcos, J.M.; Grau, A.

    1995-07-01

    A procedure for the preparation of a stable, homogeneous solution of 137Cs+''137mBa, for use in liquid scintillation measurements, is described. Its count rate stability and spectral time evolution has been followed for several weeks. The solution has been standardised by the CIEMAT/NIST method in both Ultima-Gold and Insta-Gel, to a combined uncertainty lower than 0,51 % (k=l). (Author) 5 refs.

  11. Dosimetry of ultraviolet radiation with BaHfO{sub 3} powders; Dosimetria de radiacion ultravioleta con polvos de BaHfO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Barrera A, A. A.; Aguilar D, G. A.; Guzman M, J.; Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, Col. Irrigacion, 11500 Ciudad de Mexico (Mexico); Ceron R, V., E-mail: abalba1@hotmail.com [Universidad de Guanajuato, 37670 Leon, Guanajuato (Mexico)

    2016-10-15

    Ceramic materials based on pure barium hafnate (BaHfO{sub 3}) have been obtained as a powder by the co-precipitation method. The powders obtained have a cubic structure that favors the thermoluminescent and optical properties, through which a better detection of the non-ionizing radiation is allowed. With these powders various tests were performed in the ultraviolet range at different exposure times. These thermoluminescent (Tl) studies were carried out using a Tl 3500 hand held reader which yielded a brightness curve that ranged from room temperature to the 350 degrees Celsius. This BaHfO{sub 3} response exhibits a broad brightness curve with a single peak centered around 225 degrees Celsius. Finally, is reported that there are materials of barium hafnate (BaHfO{sub 3}) doped with some rare earths (Eu, Tb) which, instead of improving the performance of the powders, decrease it, so that the use of intrinsic barium hafnate is the most appropriate. (Author)

  12. Structural and superconducting properties of Sr for Ba substituted La1.5Nd0.5Ca1(Ba2-xSrx)Cu5Oz system

    Science.gov (United States)

    Bhalodia, J. A.; Mankadia, S. R.; Dalsaniya, S. M.; Okram, G. S.

    2013-06-01

    An attempt is made to investigate the effect of isovalent substitution (i. e. Sr+2 for Ba+2) and chemical pressure effect (i.e. smaller cation substitution) on the structure and superconductivity of La1.5Nd0.5Ca1(Ba2-xSrx)Cu5Oz,x = 0.0-1.0, (LNCBSCO) system. A series of LNCBSCO system has been synthesized by a solid-state reaction route. All the compounds crystallize with the tetragonal LaBa2Cu3Oz type structure with the space group P4/mmm. The structural parameters of the prepared samples are obtained using X-ray diffraction (XRD) with Rietveld analysis. The electrical properties are also carefully investigated using the four-probe temperature dependent resistivity (R-T) technique. The oxygen content is estimated through Iodometric titration. All the samples show the well superconducting behavior with decreasing Tc values ranging from 79 K to 60 K for x = 0.0 to x = 0.8. Tc exhibits a strong correlation with doping concentration. We discuss possible reasons and inherent of the Tc(x) suppression.

  13. Micro-Raman scattering and dielectric investigations of phase transition behavior in the BaTiO{sub 3}{endash}BaZrO{sub 3} system

    Energy Technology Data Exchange (ETDEWEB)

    Dobal, P. S.; Dixit, A.; Katiyar, R. S.; Yu, Z.; Guo, R.; Bhalla, A. S.

    2001-06-15

    In this study, the phase transition behavior of the BaTiO{sub 3}{endash}BaZrO{sub 3} system was studied using micro-Raman scattering and dielectric measurement techniques. BaZr{sub x}Ti{sub 1{minus}x}O{sub 3} ceramics were prepared for x=0.00, 0.05, 0.08, 0.15, 0.20, and 1.00 compositions using a solid-state reaction technique. A single-phase perovskite structure of the ceramics was identified by the x-ray diffraction technique. The basic phase transition temperatures in these compositions were studied in the temperature range of 70{endash}575 K. The tetragonal to cubic transition temperature was found to decrease with increasing Zr content. The orthorhombic to tetragonal transition temperature that increases with an initial increase in Zr content merges with the tetragonal{endash}cubic transition for x{ge}0.15 compositions. Raman spectra of rhombohedral and orthorhombic phases could not be distinguished. Excellent agreement between the crystallographic transition temperatures obtained by both techniques suggested that Zr substituted octahedra were uniformly distributed in the material without introducing any mechanical stress. {copyright} 2001 American Institute of Physics.

  14. High mobility La-doped BaSnO3 on non-perovskite MgO substrate

    Science.gov (United States)

    Kim, Youjung; Shin, Juyeon; Kim, Young Mo; Char, Kookrin

    (Ba,La)SnO3 is a transparent perovskite oxide with high electron mobility and excellent oxygen stability. Field effect device with (Ba,La)SnO3 channel was reported to show good output characteristics on STO substrate. Here, we fabricated (Ba,La)SnO3\\ films and field effect devices with (Ba,La)SnO3 channel on non-perovskite MgO substrates, which are available in large size wafers. X-ray diffraction and transmission electron microscope (TEM) images of (Ba,La)SnO3\\ films on MgO substrates show that the films are epitaxial with many threading dislocations. (Ba,La)SnO3 exhibits the high mobility with 97.2 cm2/Vs at 2 % La doping on top of 150 nm thick BaSnO3 buffer layer. Excellent carrier modulation was observed in field effect devices. FET performances on MgO substrates are slightly better than those on SrTiO3 substrates in spite of the higher dislocation density on MgO than on SrTiO3 substrates. These high mobility BaSnO3 thin films and transistors on MgO substrates will accelerate development for applications in high temperature and high power electronics. Samsung Science and Technology Foundation.

  15. Photoinduced charge transfer properties and photocatalytic activity in Bi2O3/BaTiO3 composite photocatalyst.

    Science.gov (United States)

    Fan, Haimei; Li, Haiyan; Liu, Bingkun; Lu, Yongchun; Xie, Tengfeng; Wang, Dejun

    2012-09-26

    A series of Bi(2)O(3)/BaTiO(3) composite photocatalysts with different mass ratios of Bi(2)O(3) vs BaTiO(3) were prepared by an impregnating-annealing method. X-ray diffraction (XRD), high-resolution transmission electron microscopic (HRTEM), and UV-vis diffuse reflection spectroscopy (DRS) confirmed that Bi(2)O(3) and BaTiO(3) coexisted in the composites. The results of surface photovoltage (SPV) experiments showed enhancements of photovoltaic response in composites, which indicated a higher separation efficiency of photoinduced charges due to the establishment of an efficient interfacial electric field between Bi(2)O(3) and BaTiO(3) in the composites. The consistency of phtocatalytic activity and photovoltaic response intensity of photocatalysts showed that the efficiency interfacial electric field between Bi(2)O(3) and BaTiO(3) played an important role in improving the degradation efficiency of Rhodamine B (RhB). The 60%-Bi(2)O(3)/BaTiO(3) sample with the best activity was found by optimizing the mass ratios of Bi(2)O(3) vs. BaTiO(3). On the basis of the work function (WF) measurements, a reasonable energy band diagram was proposed for BaTiO(3)/Bi(2)O(3) composite. It would be helpful in designing and constructing high efficiency heterogeneous semiconductor photocatalyst.

  16. The Role of Area 10 (BA10) in Human Multitasking and in Social Cognition: A Lesion Study

    Science.gov (United States)

    Roca, Maria; Torralva, Teresa; Gleichgerrcht, Ezequiel; Woolgar, Alexandra; Thompson, Russell; Duncan, John; Manes, Facundo

    2011-01-01

    A role for rostral prefrontal cortex (BA10) has been proposed in multitasking, in particular, the selection and maintenance of higher order internal goals while other sub-goals are being performed. BA10 has also been implicated in the ability to infer someone else's feelings and thoughts, often referred to as theory of mind. While most of the data…

  17. Characterization of the insulator barrier and the superconducting transition temperature in GdBa{sub 2}Cu{sub 3}O{sub 7−δ}/BaTiO{sub 3} bilayers for application in tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, H., E-mail: henrynavarro@cab.cnea.gov.ar; Sirena, M.; Haberkorn, N. [Instituto Balseiro, Universidad Nacional de Cuyo and CNEA, 8400 Bariloche (Argentina); Centro Atómico Bariloche, Comisión Nacional de Energía Atómica. Av. Bustillo 9500, 8400 San Carlos de Bariloche (Argentina); Yang, Ilkyu [Department of Physics, Pohang University of Science and Technology, Pohang (Korea, Republic of); Kim, Jeehoon [Department of Physics, Pohang University of Science and Technology, Pohang (Korea, Republic of); CALDES, Institute for Basic Science, Pohang (Korea, Republic of)

    2015-07-28

    The optimization of the superconducting properties in a bottom electrode and the quality of an insulator barrier are the first steps in the development of superconductor/insulator/superconductor tunnel junctions. Here, we study the quality of a BaTiO{sub 3} tunnel barrier deposited on a 16 nm thick GdBa{sub 2}Cu{sub 3}O{sub 7−δ} thin film by using conductive atomic force microscopy. We find that the tunnel current is systematically reduced (for equal applied voltage) by increasing the BaTiO{sub 3} barrier thickness between 1.6 and 4 nm. The BaTiO{sub 3} layers present an energy barrier of ≈1.2 eV and an attenuation length of 0.35–0.5 nm (depending on the applied voltage). The GdBa{sub 2}Cu{sub 3}O{sub 7−δ} electrode is totally covered by a BaTiO{sub 3} thickness above 3 nm. The presence of ferroelectricity was verified by piezoresponse force microscopy for a 4 nm thick BaTiO{sub 3} top layer. The superconducting transition temperature of the bilayers is systematically suppressed by increasing the BaTiO{sub 3} thickness. This fact can be associated with stress at the interface and a reduction of the orthorhombicity of the GdBa{sub 2}Cu{sub 3}O{sub 7−δ}. The reduction in the orthorhombicity is expected by considering the interface mismatch and it can also be affected by reduced oxygen stoichiometry (poor oxygen diffusion across the BaTiO{sub 3} barrier)

  18. Structural and Kinetic Analysis of BaCl 2 Nanocrystals in Fluorochlorozirconate Glass-Ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Carlos J. [Materials Science and Engineering Department, Northwestern University, 2220 Campus Dr Cook Hall Room 2036 Evanston Illinois 60208; Materials Science Division, Argonne National Laboratory, 9700 S Cass Ave, Bldg 241 Argonne Illinois 60439; Leonard, Russell L. [Mechanical, Aerospace and Biomedical Engineering Department, University of Tennessee Space Institute, 411 B. H. Goethert Pkwy Tullahoma Tennessee 37388; Gray, Sharon K. [Mechanical, Aerospace and Biomedical Engineering Department, University of Tennessee Space Institute, 411 B. H. Goethert Pkwy Tullahoma Tennessee 37388; Johnson, Jacqueline A. [Mechanical, Aerospace and Biomedical Engineering Department, University of Tennessee Space Institute, 411 B. H. Goethert Pkwy Tullahoma Tennessee 37388; Petford-Long, Amanda K. [Materials Science and Engineering Department, Northwestern University, 2220 Campus Dr Cook Hall Room 2036 Evanston Illinois 60208; Materials Science Division, Argonne National Laboratory, 9700 S Cass Ave, Bldg 241 Argonne Illinois 60439; Lucas, P.

    2014-12-31

    The presence of BaCl2 nanocrystals and the crystallographic phase that they adopt controls the optical behavior of fluorochlorozirconate glass-ceramics. We have used in situ X-ray diffraction heating experiments and ex situ transmission electron microscopy to follow the BaCl2 nanocrystal nucleation and growth processes as a function of heating rate and isothermal hold temperature. The BaCl2 nanocrystals nucleate with the hexagonal crystal structure and grow as spherical particles to a size of similar to 10 to 20nm. They then undergo a structural transformation to the orthorhombic phase and their shape changes to rounded disks, with diameters ranging from 150 to 250nm, and thicknesses ranging from 80 to 120nm. The change in size results from Ostwald ripening of the hexagonal BaCl2 nanocrystals to form the orthorhombic BaCl2 nanocrystals.

  19. Long-term monitoring of Jupiter's South Temperate domain: Oval BA and the cyclic development of structured sectors

    Science.gov (United States)

    Rogers, J.; Adamoli, G.; Hahn, G.; Jacquesson, M.; Vedovato, M.; Mettig, H.-J.

    2013-09-01

    The pattern of atmospheric phenomena in Jupiter's South Temperate domain, covering the years 2001-2012, is here deduced from amateur images. We summarise the long-term history of the major features, viz. a succession of structured cyclonic sectors of the South Temperate Belt (STB), one of which is coupled to the single large anticyclonic oval (oval BA). The other structured segments begin as small dark spots or streaks remote from oval BA, then expand, and eventually catch up and merge with the dark segment at BA, inducing intense disturbance in and around it. This cycle has been completed three times in 15 years, maintaining at least 2 structured sectors at all times. The major changes in drift rate of oval BA appear to be due to the impacts and subsequent shrinkage of the structured segments. From 2008 onwards, oval BA has been shrinking and shifting southwards.

  20. Electronic Band Structure of BaCo_{2}As_{2}: A Fully Doped Ferropnictide Analog with Reduced Electronic Correlations

    Directory of Open Access Journals (Sweden)

    N. Xu

    2013-01-01

    Full Text Available We report an investigation with angle-resolved photoemission spectroscopy of the Fermi surface and electronic band structure of BaCo_{2}As_{2}. Although its quasinesting-free Fermi surface differs drastically from that of its Fe-pnictide cousins, we show that the BaCo_{2}As_{2} system can be used as an approximation to the bare unoccupied band structure of the related BaFe_{2-x}Co_{x}As_{2} and Ba_{1-x}K_{x}Fe_{2}As_{2} compounds. However, our experimental results, in agreement with dynamical-mean-field-theory calculations, indicate that electronic correlations are much less important in BaCo_{2}As_{2} than in the ferropnictides. Our findings suggest that this effect is due to the increased filling of the electronic 3d shell in the presence of significant Hund’s exchange coupling.

  1. Microwave-Hydrothermal Synthesis and Characterization of High-Purity Nb Doped BaTiO3 Nanocrystals

    OpenAIRE

    A. Khanfekr; Tamizifar, M.; R. Naghizadeh

    2014-01-01

    The synthesis of Nb doped BaTiO3 has been investigated under Microwave-Hydrothermal (MH) conditions in the temperature of 150°C for only 2 h using C16H36O4Ti, BaH2O2.8H2O and NbCl5 as Ba, Ti and  Nb sources, respectively.  Typical experiments performed on MH processing have not yet reported for Nb doped BaTiO3.  In the MH process, the formation of high purity nano tetragonal Nb-BaTiO3 was strongly enhanced. New hydrothermal method was used instead of the previous solid state reaction for the ...

  2. Theoretical investigation of structural, electronic and optical properties of MgxBa1-xS, MgxBa1-xSe and MgxBa1-xTe ternary alloys using DFT based FP-LAPW approach

    Science.gov (United States)

    Bhattacharjee, Rahul; Chattopadhyaya, Surya

    2017-11-01

    Density functional theory (DFT) based full-potential linearized augmented plane wave (FP-LAPW) methodology has been employed to investigate theoretically the structural, electronic and optical properties of MgxBa1-xS, MgxBa1-xSe and MgxBa1-xTe ternary alloys for 0 ≤ x ≤ 1 in their rock-salt (B1) crystallographic phase. The exchange-correlation potentials for the structural properties have been computed using the Wu-Cohen generalized-gradient approximation (WC-GGA) scheme, while those for the electronic and optical properties have been computed using both the WC-GGA and the recently developed Tran-Blaha modified Becke-Johnson (TB-mBJ) schemes. The thermodynamic stability of all the ternary alloys have been investigated by calculating their respective enthalpy of formation. The atomic and orbital origin of different electronic states in the band structure of the compounds have been identified from the respective density of states (DOS). Using the approach of Zunger and co-workers, the microscopic origin of band gap bowing has been discussed in term of volume deformation, charge exchange and structural relaxation. Bonding characteristics among the constituent atoms of each of the specimens have been discussed from their charge density contour plots. Optical properties of the binary compounds and ternary alloys have been investigated theoretically in terms of their respective dielectric function, refractive index, normal incidence reflectivity and optical conductivity. Several calculated results have been compared with available experimental and other theoretical data.

  3. Heterogeneous Nucleation and Growth of Barium Sulfate at Organic-Water Interfaces: Interplay between Surface Hydrophobicity and Ba(2+) Adsorption.

    Science.gov (United States)

    Dai, Chong; Stack, Andrew G; Koishi, Ayumi; Fernandez-Martinez, Alejandro; Lee, Sang Soo; Hu, Yandi

    2016-05-31

    Barium sulfate (BaSO4) is a common scale-forming mineral in natural and engineered systems, yet the rates and mechanisms of heterogeneous BaSO4 nucleation are not understood. To address these, we created idealized interfaces on which to study heterogeneous nucleation rates and mechanisms, which also are good models for organic-water interfaces: self-assembled thin films terminated with different functional groups (i.e., -COOH, -SH, or mixed -SH & COOH) coated on glass slides. BaSO4 precipitation on coatings from Barite-supersaturated solutions (saturation index, SI, = 1.1) was investigated using grazing-incidence small-angle X-ray scattering. After reaction for 1 h, a little amount of BaSO4 formed on hydrophilic bare and -COOH coated glasses. Meanwhile, BaSO4 nucleation was significantly promoted on hydrophobic -SH and mixed -SH & COOH coatings. This is because substrate hydrophobicity likely affected the interfacial energy and hence thermodynamic favorability of heterogeneous nucleation. The heterogeneous BaSO4 nucleation and growth kinetics were found to be affected by the amount of Ba(2+) adsorption onto the substrate and incipient BaSO4 nuclei. The importance of Ba(2+) adsorption was further corroborated by the finding that precipitation rate increased under [Ba(2+)]/[SO4(2-)] concentration ratios >1. These observations suggest that thermodynamic favorability for nucleation is governed by substrate-water interfacial energy, while given favorable thermodynamics, the rate is governed by ion attachment to substrates and incipient nuclei.

  4. Density variation and piezoelectric properties of Ba(Ti1−xSnx)O3 ...

    Indian Academy of Sciences (India)

    847–852. c Indian Academy of Sciences. Density variation and piezoelectric properties of Ba(Ti1−xSnx)O3 ceramics prepared from nanocrystalline powders. A K NATH. ∗ and NIRMALI MEDHI. Department of Physics, Sri Venkateswara College, University of Delhi, New Delhi 110 021, India. MS received 25 September 2011.

  5. Combustion synthesis and characterization of Ba2NdSbO6 ...

    Indian Academy of Sciences (India)

    The product was characterized by X-ray diffraction, differential thermal analysis, thermogravimetric analysis, Fourier transform infrared spectroscopy, transmission electron microscopy and scanning electron microscopy. The as-prepared powders were single phase Ba2NdSbO6 and a mixture of polycrystalline spheroidal ...

  6. Investigation of Ba2–xSrxTiO4: Structural aspects and dielectric ...

    Indian Academy of Sciences (India)

    SrTiO4 (0 ≤ ≤ 2), show that pure phases exist only for the end members, Ba2TiO4 and Sr2TiO4, crystallizing in the -K2SO4 and K2NiF4 structures, respectively. The intermediate compositions (till ≤ 1) lead to a biphasic mixture of ...

  7. Combustion synthesis and characterization of Ba2NdSbO6 ...

    Indian Academy of Sciences (India)

    Administrator

    conditions (Saberi et al 2008; Vivekanandhan et al 2008;. Yu et al 2008). But in the present work, we have synthe- sized phase pure Ba2NdSbO6 as nanoparticles through a combustion process using nitric acid as the oxidizer, citric acid as the complexing agent and ammonium hydroxide as fuel. *Author for correspondence ...

  8. Efficiency of Iranian Translation Syllabus at BA Level; Deficiency: A New Comprehensive Model

    Science.gov (United States)

    Sohrabi, Sarah; Rahimi, Ramin; Arjmandi, Masoume

    2015-01-01

    This study aims at investigating the practicality of the current curriculum for translation studies at national level (Iranian curriculum). It is going to have a comprehensive idea of translation students and teachers (university lecturers) over the current translation syllabus at BA level in Iran. A researcher-made CEQ questionnaire (Curriculum…

  9. Influence of bismuth on properties and microstructures of Sr0⋅ 5Ba0 ...

    Indian Academy of Sciences (India)

    Ba0.5–Bi TiO3 (BST, 0 < < 0.030 mol) thin films was studied. The results showed that the dielectric constant (r) and dielectric loss (tan ) decreased, and temperature, m, for maximum and r (Curie temperature), moved to lower ...

  10. Effect of low level substitution of Sr–Ba on transport and magnetic ...

    Indian Academy of Sciences (India)

    Effect of low level substitution of Sr–Ba on transport and magnetic behaviour of La0·67Ca0·33MnO3. B MUNIRATHINAM, M KRISHNAIAH. ∗. , M MANIVEL RAJA†, S ARUMUGAM†† and K PORSEZIAN#. Department of Physics, Sri Venkateswara University, Tirupati 517 502, India. †Advanced Magnetics Group, Defence ...

  11. Physical and magnetic properties of (Ba/Sr) substituted magnesium nano ferrites

    Science.gov (United States)

    Ateia, Ebtesam E.; Takla, E.; Mohamed, Amira T.

    2017-10-01

    In the presented paper, strontium (Sr) and barium (Ba) nano ferrites were synthesized by citrate auto combustion method. The investigated samples are characterized by X-ray diffraction technique (XRD), field emission scanning electron microscopy, high resolution transmission electron microscopy and energy dispersive X-ray spectroscopy. The structural properties of the obtained samples were examined by XRD analysis showing that the synthesized nanoparticles are in cubic spinel structure. The average crystallite sizes are in the range of 22.66 and 21.95 nm for Mg0.7Ba0.3Fe2O4 and Mg0.7 Sr0.3Fe2O4 respectively. The VSM analysis confirms the existence of ferromagnetic nature of Sr2+/Ba2+ substituted magnesium nano particles. Exchange interaction between hard (Sr/Ba) and soft (Mg) magnetic phases improves the structural and magnetic properties of nano ferrite particles. Rigidity modulus, longitudinal and shear wave velocities are predicted theoretically from Raman spectroscopy and structural data of the investigated spinel ferrite. The magnetic and structural properties of magnesium are enhanced by doping with barium and strontium nano particles. The saturation magnetization, remanent magnetization and coercivity reported on vibrating sample magnetometer curve illustrate the promising industrial and magnetic recording applications of the prepared samples.

  12. Ba/ZrO2 nanoparticles as efficient heterogeneous base catalyst for ...

    Indian Academy of Sciences (India)

    activity of the Ba/ZrO2 catalyst was evaluated for synthesis of β-nitro alcohols and 2-amino 2-chromenes. .... synthesized using malonic acid dihydrazide as fuel at ... from the ethanolic solution. The crude product was recrystallized using acetonitrile to afford the β-nitro alcohol in 89% yield. The used catalyst particles were.

  13. NOx conversion on LSM15-CGO10 cell stacks with BaO impregnation

    DEFF Research Database (Denmark)

    Traulsen, Marie Lund; Andersen, Kjeld Bøhm; Kammer Hansen, Kent

    2012-01-01

    The electrochemical conversion of NOx on non-impregnated and BaO-impregnated LSM15-CGO10 (La0.85Sr0.15MnO3-Ce0.9Gd0.1O1.95) porous cell stacks has been investigated, and extensive impedance analysis have been performed to identify the effect of the BaO on the electrode processes. The investigation...... was conducted in the temperature range 300-500 degrees C, a polarisation range from 3 V to 9 V and in atmospheres containing 1000 ppm NO, 1000 ppm NO + 10% O-2 and 10% O-2. On the non-impregnated cell stacks no NOx conversion was observed under any of the investigated conditions. However, BaO impregnation...... greatly enhanced the NOx conversion and at 400 degrees C and 9 V polarisation a BaO-impregnated cell stack showed 60% NOx conversion into N-2 with 8% current efficiency in 1000 ppm NO + 10% O-2. This demonstrates high NOx conversion can be achieved on an entirely ceramic cell without expensive noble...

  14. Fluorine dynamics in BaF{sub 2} superionic conductors investigated by NMR

    Energy Technology Data Exchange (ETDEWEB)

    Gumann, Patryk

    2008-07-01

    In this work the dynamics of fluorine in solid-state electrolytes having BaF{sub 2}-structure was investigated using three different NMR-methods: field cycling relaxometry, lineshape analysis, and static field gradient NMR. For this purpose a pure BaF{sub 2} crystal, as well as crystals doped with trivalent impurities (LaF{sub 3}), were studied as a function of temperature. Using MAS NMR it was possible to identify two lines in Ba{sub 0.9}La{sub 0.1}F{sub 2.1} having different chemical shift, and to refer them to the modified crystal structure. On this basis a model for the fluorine lineshape has been developed, taking into account three motional processes characterized by their correlation times. It includes jump diffusion of the fluorine ions among equivalent sites within two crystallographically distinct sublattices, and inter-lattice exchange processes. By measuring frequency and temperature-dependent spin lattice relaxation times, it was possible to gain information about fluorine dynamics on microscopic length scales. An attempt was also made to analyze the data for pure BaF{sub 2} and low admixture concentration samples with a non-exponential correlation function. (orig.)

  15. Investigations of spontaneous arc extinction in Cs-Ba plasma of highly-efficient switching converters

    Science.gov (United States)

    Mustafaev, Aleksandr; Soukhomlinov, Vladimir; Grabovskiy, Artiom; Shtoda, Evgenia

    2017-10-01

    This talk deals with the results of the research into plasma's electro kinetic parameters of Knudsen Cs-Ba high-current diode and triode switching converters. The investigations of the spontaneous arc extinction in the devices with a fine-mesh grid, operating in the collisionless mode, have been carried out. In order to study the mechanism of the arc extinction, the time dependencies of the luminosity of a series of CsI, BaII and BaI lines were obtained. The use of Cs-Ba mixture, where cesium is a plasma-forming component, allowed to obtain emission currents from the cathode up to 100 A/cm2 in Cs-pressure range 10-3-10-2 Torr and, thus, easily attain the electric power density of 5 kW/cm2 and the efficiency more than 95%1,2. It has been established, that the arc extinction in the triode, having the fine-mesh, highly-transparent grid, is due to the high degree of atom ionization and to the escape of atoms from the spacing, while the large duration of the current pulse is determined by atom desorption from the electrodes.

  16. Influence of seeding on crystallization behaviour of BaNaB9O15 ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. Transparent BaNaB9O15 (BNBO) glasses were fabricated via the conventional melt-quenching technique. X-ray powder diffraction (XRD) followed by differential scanning calorimetric (DSC) studies con- firmed the amorphous and glassy nature of the as-quenched samples, respectively. The effect of seeding on ...

  17. studies of radiative penguin decays at BaBar (*) + - * -6 * ' * * * -E ...

    Indian Academy of Sciences (India)

    Abstract. We summarize results on a number of observations of penguin dominated radiative decays of the B meson. Such decays are forbidden at tree level and proceed via electroweak loops. As such they may be sensitive to physics beyond the standard model. The observations have been made at the BaBar experiment ...

  18. Data of evolutionary structure change: 1DUIA-2V8BA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1DUIA-2V8BA 1DUI 2V8B A A --AKCVSYGVSQIKAPALHS-----QGYTGSNVKVAVID...H - HHHHHHHHHH EEE - 0 1DUI... A 1DUIA GTVLA----VAPSA ALA CA 376 ARG CA 307 ASN CA 260 1DUI... A 1DUIA AGNEGTSGSS

  19. Search for Physics Beyond the Standard Model at BaBar and Belle

    Directory of Open Access Journals (Sweden)

    Calderini G.

    2012-06-01

    Full Text Available Recent results on the search for new physics at BaBar and Belle B-factories are presented. The search for a light Higgs boson produced in the decay of different γ resonances is shown. In addition, recent measurements aimed to discover invisible final states produced by new physics mechanisms beyond the standard model are presented.

  20. Polygyny without wealth: popularity in gift games predicts polygyny in BaYaka Pygmies.

    Science.gov (United States)

    Chaudhary, Nikhil; Salali, Gul Deniz; Thompson, James; Dyble, Mark; Page, Abigail; Smith, Daniel; Mace, Ruth; Migliano, Andrea Bamberg

    2015-05-01

    The occurrence of polygynous marriage in hunter-gatherer societies, which do not accumulate wealth, remains largely unexplored since resource availability is dependent on male hunting capacity and limited by the lack of storage. Hunter-gatherer societies offer the greatest insight in to human evolution since they represent the majority of our species' evolutionary history. In order to elucidate the evolution of hunter-gatherer polygyny, we study marriage patterns of BaYaka Pygmies. We investigate (i) rates of polygyny among BaYaka hunter-gatherers; (ii) whether polygyny confers a fitness benefit to BaYaka men; (iii) in the absence of wealth inequalities, what are the alternative explanations for polygyny among the BaYaka. To understand the latter, we explore differences in phenotypic quality (height and strength), and social capital (popularity in gift games). We find polygynous men have increased reproductive fitness; and that social capital and popularity but not phenotypic quality might have been important mechanisms by which some male hunter-gatherers sustained polygynous marriages before the onset of agriculture and wealth accumulation.

  1. Dy 3-activated M2SiO4 (M= Ba, Mg, Sr)-type phosphors

    Indian Academy of Sciences (India)

    The alkaline orthosilicates of M 2 SiO 4 (M = Ba, Mg, Sr) activated with Dy 3 + and co-doped with Ho 3 + are prepared through conventional solid-state method, i.e., mixing and grinding of solid form precursors followedby high-temperature heat treatments of several hours in furnaces, generally under open atmosphere and ...

  2. Commensurability oscillations in NdBa2Cu3Oy single crystals

    Indian Academy of Sciences (India)

    parameter and the lattice constant. If the development of the splitting has finished, the differences B(a − 6) and B(7 − a) correspond however to half the lattice constant and the periodicity of the commensurate states has doubled. First, the anisotropic Bean model involving jc and ja,b as a possible explanation for the double ...

  3. Flux growth of baryte-type BaSO4 from chloridic alkaline metal solvents

    NARCIS (Netherlands)

    Ehrentraut, D.; Pollnau, Markus

    2002-01-01

    The growth of BaSO4 from high-temperature fluxes of both chloridic alkaline metal and alkaline-earth metal solvents has been investigated. Two binary alkaline-metal solvent systems containing LiCl and the additive ternary system with CsCl–KCl–NaCl where optimized with respect to solute concentration

  4. Ba/F3 cells and their use in kinase drug discovery.

    Science.gov (United States)

    Warmuth, Markus; Kim, Sungjoon; Gu, Xiang-ju; Xia, Gang; Adrián, Francisco

    2007-01-01

    Due to their ability to function as dominant oncogenes, protein kinases have become favored targets in the quest for 'molecularly-targeted' cancer chemotherapeutics. The discovery of a large number of cancer-associated mutations in the kinome, and the progress in developing specific small-molecule kinase inhibitors has increased the need for accurate, reproducible, and efficient kinase activity-dependent cellular assay systems. Ba/F3, a murine interleukin-3 dependent pro-B cell line is increasingly popular as a model system for assessing both the potency and downstream signaling of kinase oncogenes, and the ability of small-molecule kinase inhibitors to block kinase activity. Facilitated by their growth properties, Ba/F3 cells have recently been adapted to high-throughput assay formats for compound profiling. Further, several published approaches show promise in predicting resistance to small-molecule kinase inhibitors elicited by point mutations interfering with inhibitor binding. Ba/F3 cells are an increasingly popular tool in kinase drug discovery. The ability to test the transforming capacity of newly identified kinase mutations, and to profile drug candidates and compound libraries in high-throughput fashion, combined with the use of Ba/F3 cells to predict clinical resistance will greatly facilitate developments in this field.

  5. A BaF2 crystal array for high energy-ray measurements

    Indian Academy of Sciences (India)

    Abstract. We shall discuss about the scientific motivation and construction of a 7 × 7 BaF2 crystal array at Variable Energy Cyclotron Centre, Calcutta. This detector would be used to measure high energy -ray photons from GDR decay and proton–neutron bremsstrahlung reactions at the present 88'' cyclotron and upcoming ...

  6. High Pressure Properties of a Ba-Cu-Zn-P Clathrate-I

    Directory of Open Access Journals (Sweden)

    Juli-Anna Dolyniuk

    2016-08-01

    Full Text Available The high pressure properties of the novel tetrel-free clathrate, Ba8Cu13.1Zn3.3P29.6, were investigated using synchrotron powder X-ray diffraction. The pressure was applied using a diamond anvil cell. No structural transitions or decomposition were detected in the studied pressure range of 0.1–7 GPa. The calculated bulk modulus for Ba8Cu13.1Zn3.3P29.6 using a third-order Birch-Murnaghan equation of state is 65(6 GPa at 300 K. This bulk modulus is comparable to the bulk moduli of Ge- and Sn-based clathrates, like A8Ga16Ge30 (A = Sr, Ba and Sn19.3Cu4.7P22I8, but lower than those for the transition metal-containing silicon-based clathrates, Ba8TxSi46−x, T = Ni, Cu; 3 ≤ x ≤ 5.

  7. An analysis of the electrical conductivity in BaSO4-added AgZSO4

    Indian Academy of Sciences (India)

    Bull. Mater. Sci, Vol. 18, No. 3, June 1995, pp. 237*246. (6) Printed in India. An analysis of the electrical conductivity in BaSO4-added AgZSO4 solid electrolyte system. K SINGH, S M PANDE* and S S BHOGA+. Department of Physics, Nagpur University, Nagpur 440010, India. *Department of Applied Physics, Ramdeobaba ...

  8. A study on the damping capacity of BaTiO3-reinforced Al-matrix ...

    Indian Academy of Sciences (India)

    strength and high damping capacity. Ferroelectric and piezoelectric ceramics can exhibit con- siderable high vibration damping capacity due to the anelas- tic response of ferroelastic domains to an external applied stress. Some piezoelectric materials such as BaTiO3 PZT. (Pb(ZrTi)O3) and LiNbO3 have been focussed and ...

  9. Synthesis and luminescence properties of BaTiO3: RE (RE= Gd 3 ...

    Indian Academy of Sciences (India)

    Gd3+, Dy3+, Tb3+ and Lu3+ doped BaTiO3-based phosphors were synthesized with modified solidstate technique at 1000 °C. The optimization of reaction conditions were carried out by thermogravimetry and differential thermal analysis methods (DTA/TG). The reaction products obtained in an air atmosphere were ...

  10. Preparation of MAl O : Eu2+, Sm3+ (M = Ca, Sr, Ba) Phosphors by ...

    African Journals Online (AJOL)

    NJD

    2007-10-15

    Oct 15, 2007 ... A series of MAl2O4: Eu2+, Sm3+ (M = Ca, Sr, Ba) phosphors was prepared by the combustion method, and the influence of these alkaline earth metals on the structure and luminescent performances for these phosphors was investigated. A relationship was established between their composition, ...

  11. Preparation of MAl 2 O 4 : Eu 2+ , Sm 3+ (M = Ca, Sr, Ba) Phosphors ...

    African Journals Online (AJOL)

    A series of MAl2O4: Eu2+, Sm3+ (M = Ca, Sr, Ba) phosphors was prepared by the combustion method, and the influence of these alkaline earth metals on the structure and luminescent performances for these phosphors was investigated. A relationship was established between their composition, crystallization capacity and ...

  12. First-principles calculations on the four phases of BaTiO3.

    Science.gov (United States)

    Evarestov, Robert A; Bandura, Andrei V

    2012-04-30

    The calculations based on linear combination of atomic orbitals basis functions as implemented in CRYSTAL09 computer code have been performed for cubic, tetragonal, orthorhombic, and rhombohedral modifications of BaTiO(3) crystal. Structural and electronic properties as well as phonon frequencies were obtained using local density approximation, generalized gradient approximation, and hybrid exchange-correlation density functional theory (DFT) functionals for four stable phases of BaTiO(3). A comparison was made between the results of different DFT techniques. It is concluded that the hybrid PBE0 [J. P. Perdew, K. Burke, M. Ernzerhof, J. Chem. Phys. 1996, 105, 9982.] functional is able to predict correctly the structural stability and phonon properties both for cubic and ferroelectric phases of BaTiO(3). The comparative phonon symmetry analysis in BaTiO(3) four phases has been made basing on the site symmetry and irreducible representation indexes for the first time. Copyright © 2012 Wiley Periodicals, Inc.

  13. Properties of c-axis oriented Ba-ferrite sputtered films

    Science.gov (United States)

    Morisako, Akimitsu; Matsumoto, Mitsunori; Naoe, Masahiko

    1999-03-01

    In this paper, the BaM films with amorphous Fe-Ba-O underlayer were prepared by FTS system. It was found that the films with the preferential orientation of c-axis can be prepared at the substrate temperature of above 525°C. The crystallization temperature of the BaM films is between 475 and 500°C, but the grain size is 1000 Å for the film prepared at Ts of 500°C and increased with increase of Ts. It was found that the preparation BaM films with small grains is very difficult by simply changing the substrate temperature. Both Hc in perpendicular direction and in-plane direction exhibited maximum values of 3.7 and 2.7 kOe, respectively, at Ts of 500°C and they decreased with increase of Ts up to 575°C. This reduction of Hc seems to be caused by grain growth but some magneto-static coupling between each grain also should be considered.

  14. HrtBA and menaquinones control haem homeostasis in Lactococcus lactis.

    Science.gov (United States)

    Joubert, Laetitia; Derré-Bobillot, Aurélie; Gaudu, Philippe; Gruss, Alexandra; Lechardeur, Delphine

    2014-08-01

    Lactococcus lactis is a fermenting Gram-positive bacterium widely used for production of dairy products. Lacking haem biosynthesis genes, L. lactis can still shift to an energetically favourable respiratory metabolism by activating a terminal cytochrome bd oxidase when haem is added to an aerated culture. Haem intracellular homeostasis is mediated by the hrtRBA operon encoding the conserved membrane HrtBA haem efflux permease and the unique intracellular haem sensor and regulator, HrtR. Here we report that membrane-associated menaquinones (MK) favour the accumulation of reduced haem in membranes. An oxidative environment, provided by oxygen, prevents and reverses haemin reduction by MK and thus limits haem accumulation in membranes. HrtBA counteracts MK-dependent membrane retention of excess haem in membrane, suggesting direct efflux from this compartment. Moreover, both HrtBA and MK-mediated reduction have a strong impact on haem intracellular pools, as determined via HrtR haem sensor induction, suggesting that intracellular haem acquisition is controlled at the membrane level without the need for dedicated import systems. Our conclusions lead to a new hypothesis of haem acquisition and regulation in which HrtBA and the bacterial membrane have central roles in L. lactis. © 2014 John Wiley & Sons Ltd.

  15. The Institute of Biological Sciences Herbarium (PBDH), University of the Philippines Los Baños

    NARCIS (Netherlands)

    Buot, I.E.; Hernaez, B.F.; Tandang, D.N.

    2002-01-01

    With the founding of the Museum of Natural History (MNH) at the University of the Philippines Los Baños (UPLB) the former Department of Botany Herbarium (CAHUP) has been transferred to this. This required the establishment of another herbarium to cater to the increasing need by courses in

  16. Effect of thermal stabilizers (Ba/Cd/Zn metal salts carboxylate and ...

    African Journals Online (AJOL)

    The study of the photodegradation of unstabilized and stabilized PVC films has been performed by means of artificial UV light. Eight (8) mixtures of PVC have been prepared by compounding PVC powder with two kinds of stabilizers at varied concentrations. The two stabilizers used are namely Ba/Cd/Zn carboxylate and ...

  17. A re-look at critical factors influencing single-phase formation of Ba2 ...

    Indian Academy of Sciences (India)

    TECS

    A re-look at critical factors influencing single-phase formation of. Ba2. Ti9. O20 microwave dielectrics. UNNIKRISHNAN GOPINATH, DHANYA CHANDRAN, SEEMA ANSARI,. BINDU KRISHNAN, RANI PANICKER and RAGHU NATARAJAN*. Centre for Materials for Electronics Technology, Thrissur 680 771, India.

  18. Structural Studies of BaTiO 3 Ferroelectric Material Prepared by ...

    African Journals Online (AJOL)

    Nano particle Barium Titanate (BT) is the first ferroelectric ceramics and a good nominee for a variety of applications from large family of Perovskite. In this study BaTiO3 was synthesised by using Sol-gel (green chemistry) method. It is environmental friendly method and has a significant influence on the structure and ...

  19. Closing the Loop: Strengthening Disciplinary Writing in an English BA Program

    Science.gov (United States)

    Wilcox, Miranda

    2017-01-01

    This program profile narrates how the Department of English at Brigham Young University (BYU) reviewed and revised the disciplinary writing requirements in the English BA program between 2006 and 2015. The story begins in 2006 with the dual problems of recognizing the lack of development in student writing in the major and of responding to…

  20. Preparation of nanocrystalline ferroelectric BaNb2O6 by citrate gel ...

    Indian Academy of Sciences (India)

    Unknown

    Transmission electron microscopic (TEM) investigations revealed that the average particle size is 50 nm for the calcined powders. The room temperature dielectric constant at 1 kHz is found ... 1. Introduction. SrxBa1–xNb2O6 (0⋅25 < x < 0⋅75) (SBN) ceramics are ferro- electric materials with tungsten bronze type structure,.

  1. The investigation of the mechanical properties of Mn doped BaSnO3 nanoparticles

    Science.gov (United States)

    Kazah, I.; Awad, R.

    2017-07-01

    This study investigates the effect of Mn substitution on the structural and mechanical properties of nano BaSnO3 using X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), Scanning electron microscope (SEM) and Vickers microhardness. For this investigation, samples of type BaSn1-xMnxO3 with 0.04 ≤ x ≤ 0.4 were prepared by co-precipitation method. XRD patterns indicate the formation of single phase cubic structure BaSnO3 with space group (Pm3m) for 0 ≤ x ≤ 0.1. BaMnO2 hexagonal phase appears as impurity for x > 0.1. The crystallite size, increases as x increases. Vickers microhardness Hv was carried out at different applied loads varying between 0.98 N and 9.8 N at dwell time 40 seconds. The results show that Hv increases as the Mn-content increases, whereas it decreases as the applied load increase. The Hv results were analysed using Elastic Plastic Deformation and the Modified proportional specimen resistance models. The Vickers microhardness analysis indicates that Modified Proportional Specimen Resistance model is the most suitable one for describing the load independent microhardness region of the investigated samples.

  2. Pressure-induced phase transformations in the Ba8Si46 clathrate

    DEFF Research Database (Denmark)

    Yang, Lirong; Ma, Y.M.; Iitaka, T.

    2006-01-01

    The nature of isostructural transformations of a type-I Ba8Si46 clathrate has been studied by in situ high-pressure angle-dispersive x-ray powder diffraction using liquid He as pressure transmitting medium. The good quality of the diffraction data permitted refinement of structural and thermal...

  3. Characterization of BaTiO3 piezoelectric perovskite material for ...

    Indian Academy of Sciences (India)

    2017-07-28

    Jul 28, 2017 ... titanate material, at each stage of its fabrication (powder, granulate, sintered material), influencing on its application for the stacked-disk multilayer actuator .... properties and to widen the number of potential applications the BaTiO3 is doped with ..... C [35] without any mis- matching of thermal behaviours of ...

  4. Two-Dimensional Massless Dirac Fermions in Antiferromagnetic AFe_{2}As_{2} (A=Ba,Sr).

    Science.gov (United States)

    Chen, Zhi-Guo; Wang, Luyang; Song, Yu; Lu, Xingye; Luo, Huiqian; Zhang, Chenglin; Dai, Pengcheng; Yin, Zhiping; Haule, Kristjan; Kotliar, Gabriel

    2017-09-01

    We report infrared studies of AFe_{2}As_{2} (A=Ba, Sr), two representative parent compounds of iron-arsenide superconductors, at magnetic fields (B) up to 17.5 T. Optical transitions between Landau levels (LLs) were observed in the antiferromagnetic states of these two parent compounds. Our observation of a sqrt[B] dependence of the LL transition energies, the zero-energy intercepts at B=0  T under the linear extrapolations of the transition energies and the energy ratio (∼2.4) between the observed LL transitions, combined with the linear band dispersions in two-dimensional (2D) momentum space obtained by theoretical calculations, demonstrates the existence of massless Dirac fermions in the antiferromagnet BaFe_{2}As_{2}. More importantly, the observed dominance of the zeroth-LL-related absorption features and the calculated bands with extremely weak dispersions along the momentum direction k_{z} indicate that massless Dirac fermions in BaFe_{2}As_{2} are 2D. Furthermore, we find that the total substitution of the barium atoms in BaFe_{2}As_{2} by strontium atoms not only maintains 2D massless Dirac fermions in this system, but also enhances their Fermi velocity, which supports that the Dirac points in iron-arsenide parent compounds are topologically protected.

  5. Linear electro-optical properties of tetragonal BaTiO

    Indian Academy of Sciences (India)

    ... with experimental data. The covalent Ti–O bonds constituting distorted TiO6 octahedral groups are found to be major contributors to the electro-optic coefficients making them more sensitive than the BaO12 groups for these properties. Orientations of chemical bonds play an important role in determining these properties.

  6. Structural properties, electric response and electronic feature of BaSnO{sub 3} perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Cuervo Farfan, J. [Grupo de Fisica de Nuevos Materiales, Departamento de Fisica, Universidad Nacional de Colombia, AA 14490 Bogota D.C. (Colombia); Arbey Rodriguez, J.; Fajardo, F. [Grupo de Estudios de Materiales, Departamento de Fisica, Universidad Nacional de Colombia, Bogota DC (Colombia); Vera Lopez, E. [Grupo de Superficies, Electroquimica y Corrosion, UPTC, Tunja (Colombia); Landinez Tellez, D.A. [Grupo de Fisica de Nuevos Materiales, Departamento de Fisica, Universidad Nacional de Colombia, AA 14490 Bogota D.C. (Colombia); Roa-Rojas, J., E-mail: jroar@unal.edu.c [Grupo de Fisica de Nuevos Materiales, Departamento de Fisica, Universidad Nacional de Colombia, AA 14490 Bogota D.C. (Colombia)

    2009-10-01

    It has been observed that the semiconducting compound SnO{sub 2} presents very good results as gas sensor. One important development has been performed to study perovskite oxides for this relevant application. One oxide material which constitutes an excellent candidate for this technological application is BaSnO{sub 3}. Polycrystalline samples with single phase of BaSnO{sub 3} were synthesized by using the solid state reaction method. Samples were characterized structurally by means of X-ray diffraction (XRD) technique. Rietveld refinement, by using the GSAS code, reveals that this material synthesizes in a cubic perovskite, space group Pm3m (no. 221), with lattice parameter 4.1190(3)A. Electric response was examined through the impedance spectroscopy technique. Results of Bode diagram, from an equivalent circuit, evidence the semiconductor character of material. We carried out a theoretical study by means of the calculation of the bands diagram and the density of states of the BaSnO{sub 3}. Calculation was performed by employing the density functional theory (DFT), with the generalized gradient approach (GGA). DFT theory permitted to establish that BaSnO{sub 3} material has an indirect semiconducting behavior. The calculated gap for this perovskite-like stagnate is at least 0.4 eV. Bulk modulus for material was also determined to be 132 GPa.

  7. Growth of (100)-highly textured BaBiO{sub 3} thin films on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Ferreyra, C. [GIyA and INN, CNEA, Av. Gral Paz 1499, 1650 San Martín, Buenos Aires (Argentina); Departamento de Física, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 1, Ciudad Universitaria, Buenos Aires (Argentina); Marchini, F. [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Departamento de Química Inorgánica, Analítica y Química-Física, INQUIMAE-CONICET, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, Buenos Aires (Argentina); Granell, P. [INTI, CMNB, Av. Gral Paz 5445, B1650KNA San Martín, Buenos Aires (Argentina); Golmar, F. [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); INTI, CMNB, Av. Gral Paz 5445, B1650KNA San Martín, Buenos Aires (Argentina); Escuela de Ciencia y Tecnología, UNSAM, Campus Miguelete, 1650 San Martín, Buenos Aires (Argentina); Albornoz, C. [GIyA and INN, CNEA, Av. Gral Paz 1499, 1650 San Martín, Buenos Aires (Argentina); and others

    2016-08-01

    We report on the growth and characterization of non-epitaxial but (100)-highly textured BaBiO{sub 3} thin films on silicon substrates. We have found the deposition conditions that optimize the texture, and show that the textured growth is favoured by the formation of a BaO layer at the first growth stages. X-ray diffraction Φ-scans, together with the observation that the same textured growth is found on films grown on Pt and SiO{sub 2} buffered Si, demonstrate the absence of epitaxy. Finally, we have shown that our (100)-oriented BaBiO{sub 3} films can be used as suitable buffers for the growth of textured heterostructures on silicon, which could facilitate the integration of potential devices with standard electronics. - Highlights: • BaBiO{sub 3} thin films were grown on Si substrates and characterized. • Films prepared using optimized conditions are highly textured in the (100) direction. • The absence of in-plane texture was demonstrated by X-ray diffraction. • Our films are suitable buffers for the growth of (100)-textured oxide heterostructures.

  8. Physical Properties of ( {BaSnO}_{3})_mathrm{x}/ {Cu}_{0.5} {Tl}_{0.5} {Ba}_{2} {Ca}_{2} {Cu}_{3} {O}_{10{-}delta } ( BaSnO 3 ) x / Cu 0.5 Tl 0.5 Ba 2 Ca 2 Cu 3 O 10 - δ Superconductor Composite

    Science.gov (United States)

    Srour, A.; Awad, R.; Malaeb, W.; Barakat, M. ME.

    2017-11-01

    The influence of barium tin oxide nanoparticles addition on the structural and superconducting properties of the Cu_{0.5}Tl_{0.5}Ba2Ca2Cu3O_{10{-}δ } phase, (CuTl)-1223, was studied. A different wt% of BaSnO3, ranging from 0.00 to 1.50, were added into (CuTl)-1223 phase, and this composite was synthesized using the solid-state reaction technique. The phase formation and lattice parameters were calculated from X-ray powder diffraction measurements. The grain connectivity and surface morphology were identified using scanning electron microscope. Energy dispersive X-ray spectroscopy gave the real elemental composition of the prepared samples. Superconducting transition temperature ({T_c}) and critical current density ({J_c}) were determined from the electrical resistivity and I-V measurements, respectively. A complete study about the vibration modes of different atoms was carried out using Fourier transform infrared (FTIR) absorption spectroscopy of (BaSnO3)_x/CuTl-1223 composite. The increase in {T_c} and {J_c} up to x=0.25 wt% is an evidence for improving the superconducting properties of (BaSnO3)_x/CuTl-1223 composites by enhancing both the inter-grains coupling and volume fraction of the (CuTl)-1223 phase.

  9. Effect of the order and disorder of BaMoO4 powders in photoluminescent properties.

    Science.gov (United States)

    Marques, Ana Paula A; Picon, Francini C; Melo, Dulce M A; Pizani, Paulo S; Leite, Edson R; Varela, José A; Longo, Elson

    2008-01-01

    The study of the photoluminescent properties affected by order and disorder of the BaMoO(4) powders is the principal objective in this work. BaMoO(4) compounds were prepared using soft chemical process called Complex Polymerization Method. In this work, different deagglomeration types and different heating rates were used to promote different disorder degrees. Scheelite type phase (BaMoO(4)) was determined by X-ray Diffraction (XRD), Fourier Transformed Infra-Red (FTIR) and Raman spectroscopy after heat treating the sample at 400 degrees C. The room temperature luminescence spectra revealed an intense single-emission band in the visible region. Based on XRD and Raman data it was observed that the transition between the completely disordered structure to completely ordered structure is a good condition for photoluminescence (PL) emission. The best PL emission is obtained when the material possesses short range disorder, i.e., is periodically ordered (XRD), but some disorder as measured by Raman spectroscopy. The excellent optical properties observed for disordered BaMoO(4) suggested that this material is a highly promising candidate for optical applications.

  10. Managing Project Team in Local Government B.A. Amujiri Abstract ...

    African Journals Online (AJOL)

    Religion Dept

    Managing Project Team in Local Government. B.A. Amujiri. Abstract. The paper carried a distilled analysis of activities of managing project team in the local government and discovered that managing project team is indispensable in local governments because of its expertise in project execution; its professionalism in ...

  11. Nanogenerator power output: influence of particle size and crystallinity of BaTiO3

    Science.gov (United States)

    Nutal Schädli, Gian; Büchel, Robert; Pratsinis, Sotiris E.

    2017-07-01

    Lead-free piezoelectric nanogenerators made with BaTiO3 offer an attractive energy harvesting solution towards portable, battery-free medical devices such as self-powered pacemakers. Here, we assembled nanogenerators made of thin, flexible poly(vinylidene fluoride-co-hexafluoropropylene) films containing either polycrystalline BaTiO3 nanoparticles of various sizes or commercial monocrystalline particles of 64 or 278 nm in average diameter. The nanoparticles were prepared by hydrogen-driven flame aerosol technology and had an average diameter of 24-50 nm with an average crystal size of about 10 nm. The rapid cooling during nanoparticle formation facilitated the synthesis of polycrystalline, multi-domain, piezoelectrically active tetragonal BaTiO3 with a high c/a lattice ratio. Using these particles, 2 μm thin polymer nanocomposites were formed, assembled into nanogenerators that exhibited a 1.4 V time-averaged output, almost twice that of the best commercial BaTiO3 particles. That output was maintained stable for over 45 000 cycles with each cycle corresponding to a heartbeat of 60 bpm. The exceptional piezoelectric performance of these nanogenerators is traced to their constituent polycrystalline nanoparticles, having high degree of domain orientation upon poling and exhibiting the flexoelectric effect, polarization induced by a strain gradient.

  12. Incommensurate magnetism in PrBa2Cu3O6.92

    DEFF Research Database (Denmark)

    Hill, J.P.; Boothroyd, A.T.; Andersen, N.H.

    1998-01-01

    We report resonant x-ray magnetic scattering and high-resolution neutron-diffraction studies of the Pr site magnetism in high quality single crystals of PrBa2Cu3O6.92. These studies reveal that the Pr sublattice orders at 19 K in a well correlated, long period incommensurate structure with probable...

  13. Ordered oxygen deficient '112'perovskites, LnBaCo2 O5⋅ 50 ...

    Indian Academy of Sciences (India)

    ... Refresher Courses · Symposia · Live Streaming. Home; Journals; Bulletin of Materials Science; Volume 32; Issue 3. Ordered oxygen deficient '112' perovskites, LnBaCo2O5.50+: complex magnetism and transport properties. B Raveau Md Motin Seikh V Pralong V Caignaert. Volume 32 Issue 3 June 2009 pp 305-312 ...

  14. A re-look at critical factors influencing single-phase formation of Ba2 ...

    Indian Academy of Sciences (India)

    2 : 9 is found to be a stoichiometric compound and even 0.5% excess Ti or Ba leads to multiphase formation. Single-phase 2 : 9 could be achieved even through solid-state route without the addition of stabilizing agents using high purity raw materials. The present results do not agree with existing hypotheses viz. diffusion, ...

  15. Electrical treeing in ceramic-based insulating materials (Ba TiO3 ...

    African Journals Online (AJOL)

    Electrical treeing in ceramic-based insulating materials (Ba TiO3 – SiO2). ... It was observed that the tree-like structures were of two types and that the initiation could have been due to partial discharges that arose from microcracks, pores and other similar defects. This equally shows that the mechanism of the initiation of an ...

  16. Metal–insulator transition in electron-doped Ba La MnO 3 ...

    Indian Academy of Sciences (India)

    insulator transition in electron-doped ... Keywords. Colossal magnetoresistance; metal–insulator transition; electron-doped Ba1-LaMnO3. ... Samples with = 0.2-0.5 exhibit metal–insulator (M–I) transition. The maximum M–I transition ...

  17. Defining the Thermal Stability of Ba8Ga16Ge30 and its Future in Thermoelectrics

    DEFF Research Database (Denmark)

    Reardon, Hazel; Iversen, Bo Brummerstedt; Blichfeld, Anders Bank

    The majority of research on the auspicious n/p-Ba8Ga16-xGe30+x (BGG) Type-I thermoelectric clathrates has been focused on property measurements at low temperature. High temperature property measurements have also been reported for BGG, although they have not yet been fully explained. Therefore, a...

  18. X-ray excited optical luminescence studies on the system BaXY (X,Y ...

    Indian Academy of Sciences (India)

    For the fluorobromide, the undoped salt gave a broad luminescence peak located at 440 nm, while the ... The undoped BaFBr acquired a bluish pink colour, and the doped salt displayed a pink colour after the .... lived excited state, before decay, allows momentum conservation by the interaction with the lattice, so that the ...

  19. NOTES ON CONTRIBUTORS Millicent Quarcoo (BA, MPhil, PhD) is ...

    African Journals Online (AJOL)

    Admin

    He is currently a senior lecturer and Head of Department of Linguistics,. School of ... Augustina Pokua Owusu studied Linguistics and English at the University of Cape Coast, Ghana (BA). She is ... Uyilawa Usuanlele (PhD) is an associate professor at the Department of History, 443 Mahar Hall, State University of New.

  20. Indoor Spatial Monitoring of Combustion Generated Pollutants (TSP, CO, and BaP) by Indian Cookstoves

    Science.gov (United States)

    1988-07-01

    contribution from cooking. TSP concentrations were obtained gravimetrically . Future studies might determine dust and soot separately. Part of the BaP analysis...Monograph, # 98. International Development Research Centre, Ottawa. Smith, K.R., 1987: Biofuels , Air Pollution, and Health: A Global review. Plenum

  1. PROPERTIES OF Eu3+ LUMINESCENCE IN THE MONOCLINIC Ba2MgSi2O7

    Directory of Open Access Journals (Sweden)

    Shansh an Yao

    2011-09-01

    Full Text Available Red-emitting phosphors Ba2-xMgSi2O7: Eux3+ was prepared by combustion-assisted synthesis method and an efficient red emission under near-ultraviolet (UV was observed. The luminescence and crystallinity were investigated using luminescence spectrometry and X-ray diffractometer. The emission spectrum shows that the most intense peak is located at 614 nm, which corresponds to the 5D0 → 7F2 transitions of Eu3+. The phosphor has two main excitation peaks located at 394 and 465 nm, which match the emission of UV and blue light-emitting diodes, respectively. The effect of Eu3+ concentration on the emission spectrum of Ba2MgSi2O7:Eu3+ phosphor was studied. The results showed that the emission intensity increased with increasing Eu3+ concentration, and then decreased because of concentration quenching. The critical quenching concentration of Eu3+ in Ba2MgSi2O7: Eu3+ phosphor is about 0.05 mol. The mechanism of concentration quenching of Ba2MgSi2O7: Eu3+ luminescence is energy transfer between Eu3+ ions casued by the dipole-dipole interaction.

  2. Surface modification of M-Ba-ferrite powders by polyaniline: Towards improving microwave electromagnetic response

    Energy Technology Data Exchange (ETDEWEB)

    Tang Xin, E-mail: tungqin@126.com [School of Petroleum Enginering, Southwest Petroleum University, 8, Xindu Road, Xindu District, Chengdu 610500 (China); Yang Yuanguang [School of Petroleum Enginering, Southwest Petroleum University, 8, Xindu Road, Xindu District, Chengdu 610500 (China)

    2009-09-15

    A composite of polyaniline (PANI)-coated M-type hexagonal barium ferrite (M-Ba-ferrite) powder was prepared by an in situ polymerization of an aniline monomer in the presence of M-Ba-ferrite particles. The obtained composite was characterized by Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The structure and microwave response properties were investigated. The continuous coverage of polyaniline has been produced on the platelet M-Ba-ferrite particle surface, and a core-shell structure has been formed. The results show that the coverage of polyaniline has a great influence on microwave response of M-Ba-ferrite particles. A polyaniline thin layer formed on the surface of a barium ferrite particle changes the character of frequency dispersion of microwave absorption. The results indicate the existence of an interaction at the interface of polyaniline macromolecule and barium ferrite particle, which influences the physical and chemical properties of the composite. The interaction and interfacial polarization are seen as important factors contributing to the influence on microwave response of the PANI-coated ferrite composite powders.

  3. Ferroelectric Domain Structures in Low-Strain BaTiO3

    NARCIS (Netherlands)

    Everhardt, Arnoud S.; Matzen, Sylvia; Domingo, Neus; Catalan, Gustau; Noheda, Beatriz

    Epitaxial strain in ferroelectric films offers the possibility to enhance the piezoelectric performance utilizing low crystal symmetries and high density of domain walls. Ferroelectric BaTiO3 has been predicted to order in a variety of phases and domain configurations when grown under low strain on

  4. Path Integral Treatment of Proton Transport Processes in BaZrO3

    DEFF Research Database (Denmark)

    Zhang, Qianfan; Wahnstrom, Goran; Björketun, Mårten

    2008-01-01

    Nuclear quantum effects on proton transfer and reorientation in BaZrO3 is investigated theoretically using the ab initio path-integral molecular-dynamics simulation technique. The result demonstrates that adding quantum fluctuations has a large effect on, in particular, the transfer barrier. The ...

  5. Core structures of <001> {110} edge dislocations in BaTiO3

    OpenAIRE

    Yueliang Li; Lin Xie; Rong Yu; Huihua Zhou; Zhiying Cheng; Xiaohui Wang; Longtu Li; Jing Zhu

    2015-01-01

    The core structures of two types of {110} edge dislocations in BaTiO3 have been observed and investigated at the atomic scale by using aberration-corrected transmission electron microscopy (AC-TEM). The edge dislocations are both dissociated into two collinear partial edge dislocations bounding a complex stacking fault (SF). While the partial dislocations have the same Burgers vector, 1 ...

  6. PLD prepared bioactive BaTiO.sub.3./sub. films on TiNb implants

    Czech Academy of Sciences Publication Activity Database

    Jelínek, Miroslav; Vaněk, Přemysl; Tolde, Z.; Buixaderas, Elena; Kocourek, Tomáš; Studnička, Václav; Drahokoupil, Jan; Petzelt, Jan; Remsa, Jan; Tyunina, Marina

    2017-01-01

    Roč. 70, Jan (2017), s. 334-339 ISSN 0928-4931 R&D Projects: GA ČR(CZ) GA15-05864S; GA ČR(CZ) GA15-01558S Institutional support: RVO:68378271 Keywords : BaTiO 3 * thin films * pld * implants * TiNb * ferroelectricity Subject RIV: BM - Solid Matter Physics ; Magnetism

  7. Fabrication of Perovskite-type Oxide BaPbO 3 Nanoparticles and ...

    African Journals Online (AJOL)

    BaPbO3 perovskite was prepared by the sol-gel method. The physical and chemical properties of catalyst were characterized by XRD, TEM, SEM, EDX and IR techniques. The photocatalytic activity of the sample was evaluated by photocatalytic decomposition of methylene blue (MB) dye under UV irradiation. The results of ...

  8. Structure and stability of BaTiSi2O7

    DEFF Research Database (Denmark)

    Viani, Alberto; Palermo, Andrea; Zanardi, Stefano

    2015-01-01

    Due to their optical, photo-luminescence (PL), and afterglow properties, barium titanosilicates are compounds of great interest for functional materials and light-emitting devices. Among them, BaTiSi2O7 (BTS2) is certainly one of the most intriguing; it displays peculiar properties (e.g. PL orange...

  9. Study on effect of cubic- and tetragonal phased BaTiO{sub 3} on the electrical and thermal properties of polymeric nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Thanki, A.A.; Goyal, R.K., E-mail: rkgoyal72@yahoo.co.in

    2016-11-01

    Polymer matrix nanocomposites based on polycarbonate (PC) and nanosized-cubic/tetragonal phases of barium titanate (BaTiO{sub 3}) were fabricated using a solution method followed by hot pressing. The content of both cubic- and tetragonal phased BaTiO{sub 3} was varied from 0 to 50 wt%. For a given weight fraction, the dielectric constant of the nanocomposites containing tetragonal BaTiO{sub 3} is more than those of cubic BaTiO{sub 3} filled nanocomposites. Moreover, cubic BaTiO{sub 3}/PC nanocomposites showed significantly lower dissipation factor than those of tetragonal BaTiO{sub 3}/PC nanocomposites. The dielectric constant of the nanocomposites was found to be frequency-independent. The microhardness of the nanocomposites increased with increase in the BaTiO{sub 3} content (both cubic- and tetragonal-phased) compared to the pure matrix. Scanning electron microscopy showed better dispersion and good interaction of the tetragonal BaTiO{sub 3} nanoparticles in the matrix. The addition of cubic BaTiO{sub 3} nanoparticles significantly reduced the thermal stability of the nanocomposites compared to matrix while the addition of tetragonal BaTiO{sub 3} nanoparticles decreased it slightly. The glass transition temperature of the cubic BaTiO{sub 3}/PC nanocomposites decreased significantly, whereas it reduced slightly for the tetragonal BaTiO{sub 3}/PC nanocomposites. - Highlights: • The effect of cubic-BaTiO{sub 3} and tetragonal-BaTiO{sub 3} nanoparticles were studied. • Cubic-BaTiO{sub 3} nanoparticles showed better microhardness. • Tetragonal-BaTiO{sub 3} nanoparticles showed better dielectric and thermal properties. • Frequency independent dielectric constants of the nanocomposites were observed.

  10. Lead-free BaTiO3 nanowires-based flexible nanocomposite generator

    Science.gov (United States)

    Park, Kwi-Il; Bae, Soo Bin; Yang, Seong Ho; Lee, Hyung Ik; Lee, Kisu; Lee, Seung Jun

    2014-07-01

    We have synthesized BaTiO3 nanowires (NWs) via a simple hydrothermal method at low temperature and developed a lead-free, flexible nanocomposite generator (NCG) device by a simple, low-cost, and scalable spin-coating method. The hydrothermally grown BaTiO3 NWs are mixed in a polymer matrix without a toxic dispersion enhancer to produce a piezoelectric nanocomposite (p-NC). During periodical and regular bending and unbending motions, the NCG device fabricated by utilizing a BaTiO3 NWs-polydimethylsiloxane (PDMS) composite successfully harvests the output voltage of ~7.0 V and current signals of ~360 nA, which are utilized to drive a liquid crystal display (LCD). We also characterized the instantaneous power (~1.2 μW) of the NCG device by calculating the load voltage and current through the connected external resistance.We have synthesized BaTiO3 nanowires (NWs) via a simple hydrothermal method at low temperature and developed a lead-free, flexible nanocomposite generator (NCG) device by a simple, low-cost, and scalable spin-coating method. The hydrothermally grown BaTiO3 NWs are mixed in a polymer matrix without a toxic dispersion enhancer to produce a piezoelectric nanocomposite (p-NC). During periodical and regular bending and unbending motions, the NCG device fabricated by utilizing a BaTiO3 NWs-polydimethylsiloxane (PDMS) composite successfully harvests the output voltage of ~7.0 V and current signals of ~360 nA, which are utilized to drive a liquid crystal display (LCD). We also characterized the instantaneous power (~1.2 μW) of the NCG device by calculating the load voltage and current through the connected external resistance. Electronic supplementary information (ESI) available: PDF materials involve the linear superposition test results (Fig. S1) and the durability test results (Fig. S2) of BaTiO3 NWs-based NCG device. A video file (Video S1) shows the power up of an LCD screen by the NCG device without any external energy source. See DOI: 10.1039/c4nr

  11. Ba-rich sanidine megacrysts in trachytic rocks of Eslamy volcano, NW Iran

    Science.gov (United States)

    Aßbichler, Donjá; Asadpour, Manijeh; Heuss-Aßbichler, Soraya; Kunzmann, Thomas

    2016-04-01

    The Eslamy volcano is located on a peninsula at the eastern coast of Urumieh lake, NW Iran. The complex stratovolcano with gentle slope flanks exposes a collapsed caldera in the central part. Specific features are different sanidine rich rocks that occur in form of ejecta and flows. According to the field observations they are products of one volcanic event. XRF measurements show they all have trachytic compositions. Typical for this locality are the large sanidine phenocrysts. In the trachytic flow the sanidine crystals reach average size of ~4 cm embedded in a greenish-blue matrix consisting mainly of crystallized feldspar and subordinate pyroxen. Occasionally feldspar megacrysts of approx. 10 cm were observed. Na content of the sanidine megacrysts varies between 0.05 - 0.5 pfu with higher concentrations in the cores. Furthermore they show oscillatory zoning patterns caused by variations of Ba content (0-0.04 pfu). The matrix of the trachytic flow consist mainly of interlocking sanidine crystals (0.05-0.45 pfu Na) partly with Ba-rich cores containing up to 0.06 pfu Ba. In contrast to the megacrysts they show slightly higher Fe contents (0.025-0.035 pfu). The volcanic ejecta with bombs of approx. 50 cm in size were found in one distinct layer within a pyroclastic horizon. The average diameter of the feldspar phenocrysts is much smaller (0.5-2 cm). Sanidine is the main phase of these rocks (up to 80 %). As mafic phase up to 30 % pyroxen (mainly diospide) ± biotite can be observed. Accessories are magnetite ± apatite ± titanite ± zircon. In contrast to the flow rocks the main phase of the matrix of the ejecta is always glass with higher Fe2O3 (total) contents (up to 6 wt.-%) indicating a fast cooling of the sample due to ejection. They are completely depleted in Ba. In two samples zoned feldspar relicts enclosed in glass show remolten rims. Similar to flow rocks the feldspar phenocrysts of all ejecta show a complex zoning pattern, e.g. three samples expose high

  12. Wrong Forms of some Yorùbá Personal Names: Some Phonological and Sociolinguistic Implications

    Directory of Open Access Journals (Sweden)

    Reuben Olúwáfẹ́mi Ìkọ̀tún

    2014-12-01

    Full Text Available In this study, we examine the wrong forms of some Yorùbá sentences that have become personal names through compounding. The data were extracted from the Joint Admissions and Matriculation Board (JAMB lists of candidates that were considered for admission into three Nigerian Universities between the 2005 and 2010 academic sessions. The names extracted from that source were compared with names written in the staff lists of the three Universities in Nigeria. The wrongly written names were recorded on tapes and some native speakers were asked to listen to them to determine their correctness. We argue that wrong forms of some Yorùbá sentential/personal names are common occurrences and establish that they are traceable to the freedom granted by Yorùbá orthography developers. We also argue that, the confusion that results from the different spelling forms of some Yorùbá personal names is seriously observable in social interactions, labour market, schools or Colleges of Education/Universities, Embassies and Nigerian civil service both Federal and State and that court affidavits become imperative to authenticate or reconcile both the wrong and the correct forms for the purposes of admissions, appointments and overseas travelling documents. Similarly, we show that the position of the Yorùbá orthography developers has resulted in a loss of the actual pronunciation of some Yorùbá personal names which has severe implications for the semantic contents of the names as well as implications for the rich religious, cultural and philosophical heritage of the Yorùbá people.

  13. Fabrication and electrical investigations of Pb-doped BaTiO{sub 3} ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Sareecha, N., E-mail: nsareecha@hotmail.com [Laboratory of Physical Chemistry, Department of Chemistry, Islamia University of Bahawalpur (Pakistan); Shah, W.A. [Glass and Ceramics Research Centre, PCSIR Laboratories Complex, Ferozpur Road, Lahore 54600 (Pakistan); Maqsood, A. [Nano Scale Physics Laboratory, Department of Physics, Air University, PAF Complex E-9, Islamabad (Pakistan); Anis-ur-Rehman, M. [Applied Thermal Physics Laboratory, COMSATS Institute of Information and Technology, Park Road, Islamabad 44000 (Pakistan); Latif Mirza, M. [Laboratory of Physical Chemistry, Department of Chemistry, Islamia University of Bahawalpur (Pakistan)

    2017-06-01

    Electrical properties of Pb doped BaTiO{sub 3}; PBT are investigated in the wide range of temperatures (40–700 °C) at 1 kHz frequency. PBT ceramics were fabricated through solid state sintering method. Pre fired BaTiO{sub 3} prepared with Ba/Ti molar ratio of 0.98 was doped with PbCO{sub 3} (<1 mole %). XRD patterns indicated perovskite phase with tetragonal structures (P4mm). Morphological studies (SEM) revealed grain development with increasing lead contents. With lead doping and its variation, Curie temperature (T{sub C}) was shifted from 120 to 200 °C with broad dielectric constant peaks and dielectric anomalies with relaxor behavior were observed. Resistivity decreased with increasing temperature, all specimens showed semiconductor behavior with negative temperature coefficient of resistivity (NTCR) characteristics. Mobility of electrons increased with thermal activation due to hopping of charge carriers from one site to another. Ohmic conductivities and associated activation energies were evaluated by impedance spectroscopy. Conductivity followed the Arrhenius law with E{sub a} = 1.187–1.169 eV which can be attributed to the ionic conduction owning to doubly ionized oxygen vacancies. Well-defined hysteresis P-E loops measured at room temperature depicted ferroelectric properties of the materials. - Graphical abstract: Temperature dependence of dielectric constant (Ɛ′) and resistivity (ρ) for pure and Pb-doped BaTiO{sub 3} ceramics at 1 k Hz frequency. - Highlights: • Pb-doped BaTiO{sub 3}ceramics were fabricated through solid state sintering. • Electrical properties were studied at the temperatures 40–700 °C at 1 kHz. • Specimens showed negative temperature coefficient of resistivity characteristics. • Conductivity followed the Arrhenius law with E{sub a} = 1.187–1.169 eV. • Ionic conduction was supposed to be responsible for conduction process.

  14. Comportamiento dieléctrico de compuestos epoxi/aluminio/BaTiO3

    Directory of Open Access Journals (Sweden)

    Castro, M. S.

    2009-06-01

    Full Text Available In order to improve the dielectric behaviour of epoxi/BaTiO3, in this work the influence of micrometric aluminum metal flakes (Al, on the dielectric properties of epoxy / BaTiO3 composites was studied. Epoxy resin, Al and BaTiO3 were mixed using an ultrasonic mixer and composites were deposited onto glass substrates by dipping technique. Obtained materials presented good dielectric properties at room temperature, and relaxation process appeared due to the resin behaviour. Obtained results were compared with those reported in literature for similar systems.Con el objetivo de mejorar el comportamiento dieléctrico de los compuestos epoxi/BaTiO3, en este trabajo se estudió la influencia de partículas metálicas de aluminio (Al, con forma de escamas y tamaño micrométrico, sobre las propiedades dieléctricas de sistemas epoxi / BaTiO3. El material compuesto fue obtenido por la técnica de inmersión o “dipping”. La mezcla de los componentes fue llevado a cabo en mezclador ultrasónica y la deposición se realizó sobre sustratos de vidrio. Los materiales obtenidos presentaron buenas propiedades dieléctricas a temperatura ambiente, sin alcanzar el límite de percolación, y los fenómenos de relajación fueron generados por los dominios de la resina. Los valores obtenidos fueron comparados con los reportados en la bibliografía para sistemas similares.

  15. Biodistribution and Radiation Dosimetry of the Integrin Marker 64Cu-BaBaSar-RGD2 Determined from Whole-Body PET/CT in a Non-human Primate

    Directory of Open Access Journals (Sweden)

    Shuanglong Liu

    2017-10-01

    Full Text Available Introduction:64Cu-BaBaSar-RGD2 is a positron emission radiotracer taken up by integrin αvβ3, which is overexpressed in many malignancies. The aim of this study was to evaluate the biodistribution of 64Cu-BaBaSar-RGD2 in a non-human primate with positron emission tomography (PET and to estimate the absorbed doses in major organs for human.Materials and Methods: Whole-body PET imaging was done on a Siemens Biograph scanner with a male macaque monkey. After an i.v. injection of 13.1–19.7 MBq/kg of 64Cu-BaBaSar-RGD2, whole body scan was collected for a total duration of 180 min. Attenuation and scatter corrections were applied to reconstructions of the whole-body emission scan. After image reconstruction, three-dimensional volumes of interest (VOI were hand-drawn on the PET transaxial or coronal slices of the frame where the organ was most conspicuous. Time-activity curves (TACs for each VOI were obtained, and residence times of each organ were calculated by integration of the time-activity curves. Human absorbed doses were estimated using the standard human model in OLINDA/EXM software.Results: Injection of 64Cu-BaBaSar-RGD2 was well-tolerated in the macaque monkey, with no serious tracer-related adverse events observed. 64Cu-BaBaSar-RGD2 was cleared rapidly from the blood pool, with a 12.1-min biological half-life. Increased 64Cu-BaBaSar-RGD2 uptake was observed in the kidneys, and bladder, with mean percentage injected dose (ID% values at 1 h after injection ~35.50 ± 6.47 and 36.89 ± 5.48, respectively. The calculated effective dose was 15.30 ± 2.21 μSv/MBq, and the kidneys had the highest absorbed dose at 108.43 ± 16.41 μGy/MBq using the non-voiding model. For an injected activity of 925 MBq 64Cu for human, the effective dose would be 14.2 ± 2.1 mSv.Discussion: Due to the limited availability of the primates, we evaluated 64Cu-BaBaSar-RGD2 in the same monkey using three imaging sessions. Measured absorbed doses and effective doses of

  16. Epitaxial thin-film growth of Ruddlesden-Popper-type Ba{sub 3}Zr{sub 2}O{sub 7} from a BaZrO{sub 3} target by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Butt, Shariqa Hassan; Rafique, M.S.; Siraj, K.; Latif, A.; Afzal, Amina [University of Engineering and Technology, Laser and Optronics Centre, Department of Physics, Lahore (Pakistan); Awan, M.S. [Ibn-e-Sina Institute of Science and Technology (ISIT), Islamabad (Pakistan); Bashir, Shazia [Government College University, Centre for Advanced Studies in Physics, Lahore (Pakistan); Iqbal, Nida [Universiti Teknologi Malaysia, Medical Devices and Technology Group (MEDITEG), Faculty of Biosciences and Medical Engineering, Johor Bahru, Johor (Malaysia)

    2016-07-15

    Ruddlesden-Popper Ba{sub 3}Zr{sub 2}O{sub 7} thin films have been synthesized via pulsed laser deposition (PLD) technique. The optimization of deposition parameters in PLD enables the formation of thin film of metastable Ba{sub 3}Zr{sub 2}O{sub 7} phase from BaZrO{sub 3} target. In order to see the post-annealing effects on the structural and optical properties, the deposited Ba{sub 3}Zr{sub 2}O{sub 7} thin films were annealed at 500, 600 and 800 C. X-ray diffraction (XRD) reveals the formation of Ba{sub 3}Zr{sub 2}O{sub 7} phase with tetragonal structure. The changes in the surface of the deposited films were analysed by FE-SEM and AFM. The thin film post-annealed at 500 C exhibited the best structural, optical and surface properties. Furthermore, the chemical states and chemical composition of the films were determined by X-ray photoelectron spectroscopy (XPS) near the surface. The XPS results show that Ba, Zr and O exist mainly in the form of Ba{sub 3}Zr{sub 2}O{sub 7} Ruddlesden-Popper-type perovskite structure. (orig.)

  17. Strain induced enhancement of magnetization in Ba{sub 2}FeMoO{sub 6} based heterostructure with (Ba{sub x}Sr{sub 1-x})TiO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyeong-Won; Norton, David P. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Ghosh, Siddhartha, E-mail: ghoshsid@gmail.com; Buvaev, Sanal; Hebard, Arthur F. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States)

    2016-05-14

    High quality epitaxial Ba{sub 2}FeMoO{sub 6} thin films and Ba{sub 2}FeMoO{sub 6}–(Ba{sub x}Sr{sub 1−x})TiO{sub 3} bi-layer (BL) and superlattice (SL) structures were grown via pulsed laser deposition under low oxygen pressure, and their structural, magnetic, and magneto-transport properties were examined. Superlattice and bi-layer structures were confirmed by X-ray diffraction patterns. Low temperature magnetic measurement shows that the saturation magnetization (M{sub S}) is significantly higher for SLs and almost similar or lower for BLs, when compared to phase pure Ba{sub 2}FeMoO{sub 6} thin films. The variation of the coercive field (H{sub C}) follows exact opposite trend, where BL samples have higher H{sub C} and SL samples have lower H{sub C} than pure Ba{sub 2}FeMoO{sub 6} thin films. Also, a significant decrease of the Curie temperature is found in both BL and SL structures compared to pure Ba{sub 2}FeMoO{sub 6} thin films. Negative magneto-resistance is seen in all the BL and SL structures as well as in pure Ba{sub 2}FeMoO{sub 6} thin films. In contrast to the magnetic properties, the magneto-transport properties do not show much variation with induced strain.

  18. Synthesis and electrical properties of BaBiO 3 and high resistivity BaTiO 3BaBiO 3 ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Nitish [Oregon State Univ., Corvallis, OR (United States); Univ. of New South Wales, Sydney, NSW (Australia); Golledge, Stephen L. [Univ. of Oregon, Eugene, OR (United States); Cann, David P. [Oregon State Univ., Corvallis, OR (United States)

    2016-12-01

    Ceramics of the composition BaBiO3 (BB) were sintered in oxygen to obtain a single phase with monoclinic II2/mm symmetry as suggested by high-resolution X-ray diffraction. X-ray photoelectron spectroscopy confirmed the presence of bismuth in two valence states - 3+ and 5+. Optical spectroscopy showed presence of a direct bandgap at ~ 2.2eV and a possible indirect bandgap at ~ 0.9eV. This combined with determination of the activation energy for conduction of 0.25eV, as obtained from ac impedance spectroscopy, suggested that a polaron-mediated conduction mechanism was prevalent in BB. The BB ceramics were crushed, mixed with BaTiO3 (BT), and sintered to obtain BT–BB solid solutions. All the ceramics had tetragonal symmetry and exhibited a normal ferroelectric-like dielectric response. Using ac impedance and optical spectroscopy, it was shown that resistivity values of BT–BB were orders of magnitude higher than BT or BB alone, indicating a change in the fundamental defect equilibrium conditions. A shift in the site occupancy of Bi to the A-site is proposed to be the mechanism for the increased electrical resistivity.

  19. Study on Temporal and Spatial Distributions of Ba Atoms in Fluorescent Lamp Discharge Using Laser-Induced Florescence

    Science.gov (United States)

    AlyHendy, Ahmed Samir; Yamashita, Go; Yamagata, Yukihiko; Uchino, Kiichiro; Ueda, Takashi; Manabe, Yoshio

    2006-10-01

    A laser-induced fluorescence (LIF) technique was applied to the measurements of the temporal and spatial distributions of Ba atoms in the vicinity of the electrode of a fluorescent lamp operated at 60 Hz. Ground-state (61S0) Ba atoms were excited to a 51P1 level (350.1 nm) by a frequency-doubled dye laser beam, and the subsequent fluorescence (51P1-51D2, 582.6 nm) was detected. Over a whole periodic time (16.67 ms), the density of the Ba atoms was found to have two peaks, and the number of Ba atoms emitted in the anode half-cycle was about twofold larger than that emitted in the cathode half-cycle. This difference between the Ba atoms emitted during the anode half-cycle and those emitted during the cathode half-cycle was studied for lamps with different gas pressures. Ba atoms were found to be emitted mainly from the hot spot of the filament electrode. It is suggested that the main factor for Ba atom emission from the electrode is not sputtering by ion bombardment but thermal evaporation.

  20. Microwave-Hydrothermal Synthesis and Characterization of High-Purity Nb Doped BaTiO3 Nanocrystals

    Directory of Open Access Journals (Sweden)

    A. Khanfekr

    2014-01-01

    Full Text Available The synthesis of Nb doped BaTiO3 has been investigated under Microwave-Hydrothermal (MH conditions in the temperature of 150°C for only 2 h using C16H36O4Ti, BaH2O2.8H2O and NbCl5 as Ba, Ti and  Nb sources, respectively.  Typical experiments performed on MH processing have not yet reported for Nb doped BaTiO3.  In the MH process, the formation of high purity nano tetragonal Nb-BaTiO3 was strongly enhanced. New hydrothermal method was used instead of the previous solid state reaction for the BaTiO3±Nb2O3 system. The new method uses high pressure to create nano dimension particles in a lower time and temperature. In case of the phase evolution studies, the XRD pattern measurements and Raman spectroscopy were performed. TEM and FE-SEM images were taken for the detailed analysis of the particle size, surface and morphology.  Synthesis of Nb doped BaTiO3 with the Microwave-hydrothermal provides an advantage of fast crystallization and reduced crystal size when compared to existing methods.

  1. Pre-Training Reversible Inactivation of the Basal Amygdala (BA Disrupts Contextual, but Not Auditory, Fear Conditioning, in Rats.

    Directory of Open Access Journals (Sweden)

    Elisa Mari Akagi Jordão

    Full Text Available The basolateral amygdala complex (BLA, including the lateral (LA, basal (BA and accessory basal (AB nuclei, is involved in acquisition of contextual and auditory fear conditioning. The BA is one of the main targets for hippocampal information, a brain structure critical for contextual learning, which integrates several discrete stimuli into a single configural representation. Congruent with the hodology, selective neurotoxic damage to the BA results in impairments in contextual, but not auditory, fear conditioning, similarly to the behavioral impairments found after hippocampal damage. This study evaluated the effects of muscimol-induced reversible inactivation of the BA during a simultaneous contextual and auditory fear conditioning training on later fear responses to both the context and the tone, tested separately, without muscimol administration. As compared to control rats micro-infused with vehicle, subjects micro-infused with muscimol before training exhibited, during testing without muscimol, significant reduction of freezing responses to the conditioned context, but not to the conditioned tone. Therefore, reversible inactivation of the BA during training impaired contextual, but not auditory fear conditioning, thus confirming and extending similar behavioral observations following selective neurotoxic damage to the BA and, in addition, revealing that this effect is not related to the lack of a functional BA during testing.

  2. Apresentação Workshop Baía de Guanabara

    Directory of Open Access Journals (Sweden)

    Claudia Gutteres Vilela

    2003-01-01

    Full Text Available Ano 2003 Volume 26 - Workshop Baía de Guanabara Editor: Ismar de Souza Carvalho Coordenadora: Claudia Gutteres Vilela: Apresentação ISSN: 0101-9759 É com grande prazer que participo da edição do Anuário de 2003 do Instituto de Geociências, que inclui os trabalhos apresentados no Workshop Baía, realizado nos dias 12 e 13 de novembro de 2002, nesta instituição. O sucesso desse evento deve-se em grande parte aos trabalhos, apresentados sob a forma de palestras em mesas redondas ou painéis, por pesquisadores consagrados no Brasil e no exterior. O conteúdo dos trabalhos possui uma abrangência que se estende desde a Geologia até a Biologia, passando pela Oceanografia e Geografia, sempre com o objetivo comum de reunir dados sobre a Baía de Guanabara visando o diagnóstico ambiental. O Workshop Baía congregou diversas linhas de pesquisa desenvolvidas na Baía de Guanabara e regiões adjacentes, procurando uma integração das mesmas. Deste modo alguns trabalhos caracterizaram, em um contexto mais geral, a evolução do nível do mar na região sudeste durante o Holoceno, bem como apresentaram a neotectônica da região. Geoquímica orgânica de hidrocarbonetos e de metais pesados, sedimentologia e hidrogeologia integraram-se à distribuição de microorganismos nos sedimentos e na água, analisando diversas respostas a diferentes graus de poluição em regiões distintas. Um zoneamento ambiental ofereceu uma visão dinâmica das condições naturais e sociais do conjunto da Baía de Guanabara. A importância do workshop deve-se à busca de uma integração maior dos trabalhos acadêmicos para aplicação à gestão do desenvolvimento sustentável da Baía de Guanabara e seu entorno, que abriga a cidade do Rio de Janeiro e se constitui em uma das regiões com maior índice demográfico do Brasil. Seu impacto pode se avaliado pela presença de representantes de órgãos públicos como a SERLA, a Prefeitura de Niterói e ONGs ligadas a

  3. Caminhos para a gestão integrada do território no Vale do Paraíba de 1950 a 2004

    Directory of Open Access Journals (Sweden)

    José Luiz Ronca Caruso

    2004-01-01

    Full Text Available The Paraíba Valley region and its political-administrative frame. The region and its two phases of Planning: the economic development and the sustainable one. The Paraíba Valley Road System as a policy of the economic planning. The Paraíba Valley Region and its physical conformation: the Paraíba do Sul river basin. The water resources management in the Paraíba do Sul river basin. Two levels of management: the federal and the one of the State. The water resources Planning and its possibilities for a sustainable development of the region, through a comprehensive management

  4. Y Ba{sub 2}Cu{sub 3}O{sub 7} synthesis using microwave heating

    Energy Technology Data Exchange (ETDEWEB)

    Agostino, Angelo [Dipartimento di Chimica Generale ed Organica Applicata, Universita di Torino, C. so Massimo d' Azeglio, 48 10125 Torino (Italy); Benzi, Paola [Dipartimento di Chimica Generale ed Organica Applicata, Universita di Torino, C. so Massimo d' Azeglio, 48 10125 Torino (Italy); Castiglioni, Mario [Dipartimento di Chimica Generale ed Organica Applicata, Universita di Torino, C. so Massimo d' Azeglio, 48 10125 Torino (Italy); Rizzi, Nicoletta [Dipartimento di Chimica Generale ed Organica Applicata, Universita di Torino, C. so Massimo d' Azeglio, 48 10125 Torino (Italy); Volpe, Paolo [Dipartimento di Chimica Generale ed Organica Applicata, Universita di Torino, C. so Massimo d' Azeglio, 48 10125 Torino (Italy)

    2004-04-01

    The superconducting material Y Ba{sub 2}Cu{sub 3}O{sub 7-x} was prepared by microwave heating of an oxide mixture (Y{sub 2}O{sub 3}, BaO, CuO). The time required for the synthesis is reduced to about 3.5 h compared to 1-2 days if conventional heating is used. If during the microwave heating the boat containing the starting powders is surrounded by SiC, the Y{sub 2}BaCuO{sub 5} insulating phase does not appear.

  5. Watershed, Weddings and Workforces: Migration, Sedentarization, and Social Change among the BaAka of Southwestern Central African Republic

    OpenAIRE

    KRETSINGER, Anna L.; Hardin, Rebecca

    2003-01-01

    This brief demographic history of the BaAka pygmies of the Dzanga-Sangha Dense Forest Reserve analyses the BaAka's engagement with capital and the extent to which it influences immigration. The BaAka villages within the reserve have been influenced differently by coffee and timber boom/bust cycles. We superimpose local economic history with demographic data, then using five parameters; residence, place of origin, estimated year of birth, sex and parental place of origin, we seek to establish ...

  6. Eu-Doped BaTiO3 Powder and Film from Sol-Gel Process with Polyvinylpyrrolidone Additive

    Directory of Open Access Journals (Sweden)

    Geneviève Chadeyron

    2009-09-01

    Full Text Available Transparent BaTiO3:Eu3+ films were prepared via a sol-gel method and dip-coating technique, using barium acetate, titanium butoxide, and polyvinylpyrrolidone (PVP as modifier viscosity. BaTiO3:Eu3+ films ~500 nm thick, crystallized after thermal treatment at 700 ºC. The powders revealed spherical and rod shape morphology. The optical quality of films showed a predominant band at 615 nm under 250 nm excitation. A preliminary luminescent test provided the properties of the Eu3+ doped BaTiO3.

  7. Synthesis of Mfe12o19 (M=ba,sr) Hexaferrite Nano-particle Using Co-precipitation Method

    OpenAIRE

    Winatapura, Didin S; Sukirman, E; Ridwan

    2011-01-01

    Synthesis of MFe12O19 (M=Ba,Sr) hexaferrite nano-particle using co-precipitation method has been done. Base materials used has a high purity according to Merck catalog of Ba(NO3)2.6H2O, Sr(NO3).6H2O, dan Fe(NO3)3.9H2O powders. In co-precipitation method Ba(II), Sr(II) and Fe(II) hydroxide precursors were precipitated during the reaction between the aqueous solution of metal nitrates and 1-M aqueous solution of natrium hydroxide, which served as a precipitating reagent. The precipitation was p...

  8. Eu-Doped BaTiO3 Powder and Film from Sol-Gel Process with Polyvinylpyrrolidone Additive

    Science.gov (United States)

    García-Hernández, Margarita; García-Murillo, Antonieta; de J. Carrillo-Romo, Felipe; Jaramillo-Vigueras, David; Chadeyron, Geneviève; De la Rosa, Elder; Boyer, Damien

    2009-01-01

    Transparent BaTiO3:Eu3+ films were prepared via a sol-gel method and dip-coating technique, using barium acetate, titanium butoxide, and polyvinylpyrrolidone (PVP) as modifier viscosity. BaTiO3:Eu3+ films ~500 nm thick, crystallized after thermal treatment at 700 ºC. The powders revealed spherical and rod shape morphology. The optical quality of films showed a predominant band at 615 nm under 250 nm excitation. A preliminary luminescent test provided the properties of the Eu3+ doped BaTiO3. PMID:19865533

  9. Eu-Doped BaTiO3 Powder and Film from Sol-Gel Process with Polyvinylpyrrolidone Additive

    OpenAIRE

    Geneviève Chadeyron; Damien Boyer; Elder De la Rosa; David Jaramillo-Vigueras; Carrillo-Romo, Felipe de J.; Antonieta García-Murillo; Margarita García-Hernández

    2009-01-01

    Transparent BaTiO3:Eu3+ films were prepared via a sol-gel method and dip-coating technique, using barium acetate, titanium butoxide, and polyvinylpyrrolidone (PVP) as modifier viscosity. BaTiO3:Eu3+ films ~500 nm thick, crystallized after thermal treatment at 700 ºC. The powders revealed spherical and rod shape morphology. The optical quality of films showed a predominant band at 615 nm under 250 nm excitation. A preliminary luminescent test provided the properties of the Eu3+ doped BaTiO3.

  10. Eu-doped BaTiO₃powder and film from sol-gel process with polyvinylpyrrolidone additive.

    Science.gov (United States)

    García-Hernández, Margarita; García-Murillo, Antonieta; de J Carrillo-Romo, Felipe; Jaramillo-Vigueras, David; Chadeyron, Geneviève; De la Rosa, Elder; Boyer, Damien

    2009-09-17

    Transparent BaTiO(3):Eu(3+) films were prepared via a sol-gel method and dip-coating technique, using barium acetate, titanium butoxide, and polyvinylpyrrolidone (PVP) as modifier viscosity. BaTiO(3):Eu(3+) films ~500 nm thick, crystallized after thermal treatment at 700 masculineC. The powders revealed spherical and rod shape morphology. The optical quality of films showed a predominant band at 615 nm under 250 nm excitation. A preliminary luminescent test provided the properties of the Eu(3+) doped BaTiO(3).

  11. High-pressure Synthesis and Physical Properties of New Filled Skutterudite Compound BaOs4P12

    Science.gov (United States)

    Deminami, S.; Kawamura, Y.; Chen, Y. Q.; Kanazawa, M.; Hayashi, J.; Kuzuya, T.; Takeda, K.; Matsuda, M.; Sekine, C.

    2017-10-01

    We have succeeded in synthesizing samples of new filled skutterudite compound BaOs4P12 using the high-pressure synthesis technique. The physical properties of the compound are reported for the first time. The electrical resistivity decreases with decreasing temperature, and drop sharply around 1.8K. This indicates that BaOs4P12 is a new superconductor. Before the high-pressure synthesis, using synchrotron radiation x-ray, we tried to observe synthesizing processes of BaOs4P12 in-situ at high temperature and high pressure to obtain the optimum condition for synthesis.

  12. Síntesis de polvos de BaTiO3 por mecanoquímica

    Directory of Open Access Journals (Sweden)

    Villaquirán Raigoza, C. F.

    2002-02-01

    Full Text Available The barium titanato, BaTiO3, is one of the electronic ceramics with more history of technological application in the industry of the ceramic capacitores. The actual technological demands, and the high quality required for the electronic devices, have driven to new alternatives of prosecution of these materials and to optimize the traditional techniques of raw materials synthesis it prevails. An alternative synthesis is to use the mechanical energy to modify the physiochemical properties of the dispersed system and to favor the obtaining of powders of BaTiO3. In this work the results are indicated obtained when using mechanical activation, physicochemistry, in the obtaining of the BaTiO3. It has been analyzed the effect of the time of mill and the nature of the precursor of the titanium on the transformation of phases in the samples during the thermal treatment to that are subjected. X-ray diffraction, DRX, was used to study the phases evolution and infrared spectroscopy, FTIR, to determine the functional groups present in the samples.El titanato de bario, BaTiO3, es uno de los cerámicos electrónicos con mayor historia de aplicación tecnológica en la industria de los capacitores cerámicos. Las demandas tecnológicas actuales, y la alta calidad requerida para los dispositivos electrónicos, han conducido a nuevas alternativas de procesamiento de estos materiales y a optimizar las técnicas tradicionales de síntesis de materia prima. Una alternativa de síntesis es utilizar la energía mecánica para modificar las propiedades fisicoquímicas del sistema disperso y favorecer la obtención de polvos de BaTiO3. En este trabajo se indican los resultados obtenidos al utilizar activación mecánica, mecanoquímica, en la obtención del BaTiO3. Se ha analizado el efecto del tiempo de molienda y la naturaleza del precursor del titanio sobre la transformación de fases que experimentan las muestras durante el tratamiento térmico a que son sometidas

  13. Structural evolution of Ba{sub 8}Ti{sub 3}Nb{sub 4}O{sub 24} from BaTiO{sub 3} using a series of Ba(Ti{sub 1−5x}Nb{sub 4x})O{sub 3} solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Barrientos Hernández, F.R., E-mail: frbh68@hotmail.com [Academic Area of Earth Sciences and Materials, Autonomous University of Hidalgo State, Road Pachuca-Tulancingo km 4.5, Mineral de la Reforma zip code 42184, Hidalgo (Mexico); Department of Metallurgical and Materials Engineering, ESIQIE, National Polytechnic Institute, UPALM, Zacatenco, Mexico City, zip code 07738 (Mexico); Lira Hernández, I.A. [Department of Metallurgical and Materials Engineering, ESIQIE, National Polytechnic Institute, UPALM, Zacatenco, Mexico City, zip code 07738 (Mexico); Industrial Engineering Department, Technological Institute of Pachuca, Road México-Pachuca km. 87.5, Pachuca de Soto zip code 42080, Hidalgo (Mexico); Gómez Yáñez, C. [Department of Metallurgical and Materials Engineering, ESIQIE, National Polytechnic Institute, UPALM, Zacatenco, Mexico City, zip code 07738 (Mexico); Arenas Flores, A. [Academic Area of Earth Sciences and Materials, Autonomous University of Hidalgo State, Road Pachuca-Tulancingo km 4.5, Mineral de la Reforma zip code 42184, Hidalgo (Mexico); Cabrera Sierra, R. [Department of Metallurgical and Materials Engineering, ESIQIE, National Polytechnic Institute, UPALM, Zacatenco, Mexico City, zip code 07738 (Mexico); Pérez Labra, M. [Academic Area of Earth Sciences and Materials, Autonomous University of Hidalgo State, Road Pachuca-Tulancingo km 4.5, Mineral de la Reforma zip code 42184, Hidalgo (Mexico)

    2014-01-15

    Highlights: • The evolution phase Ba{sub 8}Ti{sub 3}Nb{sub 4}O{sub 24} was obtained through the mechanism Ba(Ti{sub 1-5x}Nb{sub 4x})O{sub 3}. • Addition of niobium can accelerate grain growth of BaTiO{sub 3} ceramics. • Ba{sub 8}Ti{sub 3}Nb{sub 4}O{sub 24} presents a dielectric loss of 0.0035 and permittivity value of 54.6. • Electrical measurements showed that Nb{sup 5+} content drops Curie temperature. • Samples with x ⩾ 0.0625 shows an insulating behavior. -- Abstract: In this work, the structural evolution of hexagonal phase Ba{sub 8}Ti{sub 3}Nb{sub 4}O{sub 24} by adding Nb{sub 2}O{sub 5} to perovskite structure of BaTiO{sub 3} was investigated. The compositions Ba(Ti{sub 1-5x}Nb{sub 4x})O{sub 3} ceramics, with 0.00025 ⩽ x ⩽ 0.125 were prepared by the conventional solid state route in air atmosphere, the powders precursors, BaTiO{sub 3}, BaCO{sub 3} and Nb{sub 2}O{sub 5}, were mixed in stoichiometric proportions and ground in a ball mill using alumina balls and acetone. The mixed powders were calcined at temperatures up to 1500 °C. The phase transformation of Ba{sub 8}Ti{sub 3}Nb{sub 4}O{sub 24} from BaTiO{sub 3} was studied by DRX, Raman spectroscopy, SEM, electrical measurements (relative permittivity and P–E hysteresis loops); Rietveld’s refinement was used to structurally characterize the samples. For the devices obtained capacitance was measured at 1 kHz; with these values we calculated the relative permittivity. The samples show typical P–E hysteresis loops at room temperature accompanied by saturation polarization (Ps) and remnant polarization (Pr). The DRX and Rietveld’s refinement results show x ⩽ 0.01 has a ferroelectric behavior. When the doped level is increased x ⩾ 0.02, a peak displacement is observed, this is due to the phase transformation of tetragonal to cubic into the unit cell. Finally, with x = 0.125 the crystal structure transforms to the characteristic hexagonal phase Ba{sub 8}Ti{sub 3}Nb{sub 4}O{sub 24} which

  14. Piezoelectric properties of electrospun nanofibers of BaTiO3; Propiedades piezoeletricas de nanofibras eletrofiadas de BaTiO3

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, L.F.R.M.; Melo, G.F.; Goncalves, A.M.; Eiras, J.A.; Bretas, R.E.S., E-mail: bretas@ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil)

    2016-07-01

    BaTiO3 nanofibers were produced by the electrospinning method from a mixture of a solution of the precursors Ba (CH{sub 3}COO){sub 2} and [(CH{sub 3}){sub 2}CHO]{sub 4}Ti in acetic acid and a solution of poly(vinylpyrrolidone) in ethanol. A voltage of 10 kV and a working distance of 4.6 cm were used for the electrospinning, at controlled room temperature and humidity of 21 °C and 60% respectively. Nanofibers as spun were dried in air on an air-circulating oven at 100 °C for one hour to remove residual solvent and were subsequently calcined at 750 °C during 2 h. The morphology, crystallographic structure and piezoelectric properties of the nanofibers were analyzed by scanning electron microscopy (SEM), X-ray angle (WAXS) and Piezoresponse Force Microscopy (PFM), respectively. The average diameter of the nanofibers was 414 nm with an aspect ratio of 40. By PFM, there was strong evidence that the nanofibers had piezoelectric activity. (author)

  15. Citric Acid Addition to Controlling Crystallization of Barium Sulphate (BaSO4) in Pipes through Ba2+ Concentration Variation in the Solution

    Science.gov (United States)

    Ivanto, G.; Fatra, F.; Dera, N. S.; Muryanto, S.; Bayuseno, A. P.

    2017-05-01

    The scale of barium sulphate (BaSO4) is common scale for mineral deposit that found in the offshore oil and gas exploitation. This scale is related with precipitation and grown of mineral deposit on the pipelines surface. Therefore, it results in blockage at the pipe. This paper presents the experimental scaling of barium sulphate in the laminar flow. The barium sulphate solution was prepared by mixing an equimolar solution of barium chloride (BaCl2) and sodium sulphate (Na2SO4). The flow rate is 40 ml/min at temperature of 50 °C. The solutions added by citric acid (C6H8O7) with variation concentration of 0 ppm, 5 ppm, and 10 ppm. The crystallization of barium sulphate was measured by using the conductivity meters. The barite crytals were dried and characterized by using SEM/EDX and XRD. The SEM Results show that the morphology of Barite scale was change in the presence of citric acid. The mineral of barium sulphate was pure barite based on the XRD phase analysis. The presence of citric acid clearly inhibit the crystallization of barium sulphate.

  16. Numerical solutions of anharmonic vibration of BaO and SrO molecules

    Science.gov (United States)

    Pramudito, Sidikrubadi; Sanjaya, Nugraha Wanda; Sumaryada, Tony

    2016-03-01

    The Morse potential is a potential model that is used to describe the anharmonic behavior of molecular vibration between atoms. The BaO and SrO molecules, which are two almost similar diatomic molecules, were investigated in this research. Some of their properties like the value of the dissociation energy, the energy eigenvalues of each energy level, and the profile of the wavefunctions in their correspondence vibrational states were presented in this paper. Calculation of the energy eigenvalues and plotting the wave function's profiles were performed using Numerov method combined with the shooting method. In general we concluded that the Morse potential solved with numerical methods could accurately produce the vibrational properties and the wavefunction behavior of BaO and SrO molecules from the ground state to the higher states close to the dissociation level.

  17. Some diffusive properties of oxygen in Y-Ba-Cu-O systems

    Energy Technology Data Exchange (ETDEWEB)

    Djurek, D.; Manojlovie, V.; Medunie, Z. (Volta Applied Ceramics, Zagreb, (YU)); Prester, M. (Zagreb Univ. (YU). Inst. za Fiziku); Babie, E.; Zadro, K. (Yugosla Academy of Sciences and Arts, Zagreb (YU))

    1992-01-01

    We have studied the diffusive properties of oxygen in Y-Ba-Cu-O systems at 940 {sup 0}C by measurements of the resistive response time {tau} of the samples subjected to the step-like increase of the oxygen pressure from 1 to 5 bars. The superconducting (SC) transition widths plotted versus inverse diffusion constant obey the universal linear dependence. The characteristic protruded tail of the real part of AC susceptibility which exhibits the feature at 86 K is absent in samples with the nominal composition Y{sub 3}Ba{sub 3}Cu{sub 6}O{sub x} (Y-336) in the regime {tau}<3 s as result of weakly connected grains of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (Y-123) nucleated from decomposed Y-336 phase.

  18. Rapid 3D Track Reconstruction with the BaBar Trigger Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, S

    2004-05-24

    As the PEP-II luminosity increases the BaBar trigger and dataflow systems must accommodate the increasing data rate. A significant source of background events at the first trigger level comes from beam particle interactions with the beampipe and synchrotron masks, which are separated from the interaction region by more than 20 cm. The BaBar trigger upgrade will provide 3D tracking capabilities at the first trigger level in order to remove background events by distinguishing the origin of particle tracks. Each new z{sub 0} p{sub T} Discriminator (ZPD) board processes over 1 gigabyte of data per second in order to reconstruct the tracks and make trigger decisions based upon the 3D track parameters.

  19. Reading teh Myth: Public Teaching of Abu Bakar Ba'asyir

    Directory of Open Access Journals (Sweden)

    Timothy Earl Behrend

    2003-12-01

    Full Text Available Abu Bakar Ba 'asyir, menurut media di luar Indonesia, dituduh sebagai penganjur terorisme dan revolusi melalui organisasi yang disebut Jamaah Islamiyah. Namanya sering dikaitkan dengan Al Qaidah, dan sejumlah peristiwa terorisme. Ia ditangkap karena desakan sejumlah negara atas Indonesia, melalui tuduhan sebagai aktor terorisme. Abu Bakar Ba'asyir sendiri merupakan seorang muslim taat, disiplin, tetapi juga absolutis dan simplistis. Ia memang, melalui pengajarannya, tampak berobsesi menegakkan syari'at Islam di negara Indonesia, untuk mengganti sistem kafir. Dalam hal ini, ia seorang radikalis. Tetapi, sesungguhnya ia bukan penganjur terorisme dan kekerasan dalam mencapai tujuannya, sebagaimana dituduhkan media. Sikap radikalnya, sesungguhnya, tak beda dengan sikap radikal kaum Kristen fundamentalis yang pernah terjadi di barat, terutama Amerika Serikat. Selain itu, ia juga sangat menentang Amerika yang dipandangnya telah melakukan hegemoni dan terorisme budaya.

  20. Platinum coating of solution-spun Y 1Ba 2Cu 3O X filament

    Science.gov (United States)

    Goto, Tomoko; Niwa, Masato; Kawanaka, Asaichi

    1992-05-01

    Platinum coating of partially melted Y 1Ba 2Cu 3O X filament produced by solution spinning is examined in order to enhance the Jc of the filament. The filament was prepared by solution spinning through a homogeneous aqueous solution containing mixed acetates of Y, Ba and Cu, polyvinyl alcohol and organic acids. The heated filaments are dip-coated in aquious solution of Pt chlorate. By controlling the melt-growth process of the filament, dense and highly oriented textures are produced and a maximum transport JCT of 36 000 A/cm 2 at 77 K and 0 T is achieved. The fiber axis of the filament appears to coincide with the direction perpendicular to the c-axis of the orthorhombic phase in the superconducting layer. The JCT of the filament is strongly dependent on the degree of crystal orientation.