November 2, by JahLive81in Masonry (2 columns), Masonry (3 columns), Portfolio (2 columns), Portfolio (3 columns)
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Phasellus id diam lectus. Pellentesque malesuada fermentum nibh a eleifend. Sed condimentum lectus ut nulla gravida, vitae commodo metus congue. Fusce volutpat enim ut elit tincidunt, ut convallis urna volutpat. Vestibulum eleifend imperdiet molestie. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Nunc sagittis sem erat, non lobortis orci faucibus vitae. Aliquam bibendum arcu metus, in scelerisque justo sagittis in. Sed accumsan hendrerit efficitur. Sed fringilla luctus nulla nec auctor. Phasellus mi eros, scelerisque efficitur est sed, malesuada gravida eros. Sed dapibus laoreet diam, ut vehicula mauris molestie sed. Duis auctor et velit in cursus.
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İngilizce, oldukça önemli bir dildir. Dünya dili olarak da kabul edilen İngilizce dili, kişiye pek çok açıdan avantaj sağlar. İş hayatında ya da okul hayatında İngilizce dilini bilmenin önemi bir hayli büyüktür. İngilizce eğitim seti İngilizce öğrenme sürecine büyük oranda katkı sağlayacak aynı zamanda öğrenme sürecini keyifli bir deneyim haline dönüştürmeye yardımcı olacak bir settir. Hem yetişkinler için pek çok çeşidi bulunmakta, hem de çocuklar için pek çok farklı çeşidi bulunmaktadır. Aynı zamanda eğitim setlerinin avantajları da oldukça fazladır.
Eğitim setleri, kişiyi çalışma için motive eder ve de bir düzen içerisinde ilerlemesini sağlar. Set içinde yer alan kitaplar, kişinin ihtiyacı olan bilgiyi almasını ve de ilerleyişini kolayca takip etmesini sağlar. İlerleme sürecini takip eden kişi, öğrenme sürecinde ihtiyacı olan noktaları da kolayca fark edebilir ve bu farkındalık ile gerektiği şekilde ilerleme kat edebilir. Siz de kendinize uygun İngilizce öğrenme seti ile İngilizce dilini keyifli bir deneyim olarak ve sağlam bir şekilde ilerleyerek kolaylıkla öğrenebilirsiniz. İngilizce öğrenmek isteyen kişilere İngilizce eğitim seti tavsiye olarak sunulması uygun olan bilgi paketlerindendir.
Eğitim setleri ile dil öğrenmek oldukça keyifli bir deneyimdir. Kontrollü bir şekilde ilerlemek, dil öğrenmede kişiye pek çok avantaj kazandırır. İlerleme süreci, nerede olduğunu bilmek kişiye bir özgüven ve de ilerlemek için bir motivasyon sağlayacaktır. Aynı zamanda kişi geçmişte öğrendiklerini el altında tutabilecek böylece eksik hissettiği noktaları hemen fark edip gereken boşlukları rahat bir şekilde doldurabilecektir. Tüm bunlara ek olarak küçük yaşta dil öğrenmek, bir çocuğa kazandırılabilecek en değerli şeylerden biridir. Araştırmaların da desteklediği gibi çocuk yaşta dil öğrenmek, yetişkinlikte dil öğrenmeye göre daha kolaydır. Çocukken dil yapısı yabancı bir dil öğrenmeye daha yatkın olmaktadır. Çocuklar için İngilizce eğitim seti küçük yaşta dil öğrenmek için ideal seçimler arasında yer almaktadır. Çocuğun yaşına göre ayrılan İngilizce eğitim setleri, dil gelişimini destekler. 4 yaş, 5 yaş ve de 6 yaş İngilizce eğitim seti ile siz de çocuğunuzun küçük yaşta dil gelişimini destekleyebilir ve de ileride böyle bir avantaja sahip olmasını sağlayabilirsiniz. Tüm bunlara ek olarak dört yaşından küçük çocuklar için dahi eğitim setleri mevcuttur. 0-3 yaş İngilizce eğitim seti ile eğitime erkenden başlayabilirsiniz.
Hem çocuklar için, hem de yetişkinler için pek çok çeşidi bulunan eğitim setleri kişinin ihtiyacına göre değişiklik gösterebilir. İngilizce eğitim seti alırken öncelikle öğrenilmek istenen düzeye karar verilmelidir. Sıfırdan ileri seviye İngilizce eğitim seti İngilizce bilmeyen ve de öğrenmek isteyen bireyler için uygun bir eğitim seti olacaktır. Bu set ile sıfırdan başlayarak İngilizce hakkında sahip olmanız gereken bilgilere ulaşabileceksiniz. Aynı zamanda bu set sizi zorlamayacak, yavaşça ama sağlam bir şekilde ilerlemenizi sağlayacaktır. Eğer ki İngilizce dilinde bir miktar başlangıcınız var ise ve ilerletmek istiyor iseniz a1-a2 İngilizce eğitim seti tercih edebilirsiniz. Temelde sahip olduğunuz birtakım bilgilerin üzerine bu set ile eklemeler yapabilir ve İngilizcenizi kolay ve de rahat bir şekilde geliştirebilirsiniz. İngilizce dilinde kendinizi okuma yaparak geliştirmek isterseniz İngilizce kitap seti tam size göre olacaktır. Okuma yapmak, dilin doğal akışını yakalamanıza ve cümle yapılarını öğrenmenize büyük oranda katkı sağlar. Bu nedenle İngilizce hikâye seti eğlenceli bir şekilde İngilizce dilinde ilerlemeniz için size yardımcı olacaktır. İngilizce eğitim seti fiyatları, farklı setlere göre çeşitlilik göstermektedir. Trendyol üzerinden kendinize uygun seti seçebilirsiniz.
Journal
of
Qafqaz
University
Editor-in-Chief
Niftali Qodjayev
Managing Editor
Elchin Suleymanov
Editorial Board
Member Irada Aliyeva
Member Muharrem Kaplan
Member Murat Erguvan
Member Islam Huseynov
Secretary Ramil Haciyev
Advisory Board
Abdul Aziz Abdul Hafis El Khouli (Egupt, Cairo University) Latif Huseynov (Azerbaijan, National Assembly)
Ali Fuat Bilkan (Turkey, University of Economics and Tekhnology) Oktay Gasimov (USA, California University)
Ajdar Agaev (Azerbaijan Institute of Education Problems) Muhammed Tebrizi (USA, East Carolina University)
Akif Huseynli (Azerbaijan, National Academy of Science) Muhittin Shimshek (Turkey, Sakarya University)
Ali Çelik (Turkey, Karadeniz Technical University) Nadir Alishov (Ukraine, Academy of Science)
Bakhram Asgerov (Azerbaijan, Baku State University) Nazan Bekiroglu (Turkey, Karadeniz Technical University)
Don C. Hines (USA, Troy University) Nadir Seyidov (Azerbaijan, National Academy of Science)
Erhan Birgili (Turkey, Sakarya University) Rasim Alikuliyev (Azerbaijan, National Academy of Science)
Erol Oral (Kyrgyzstan, International Ataturk-Alatoo University) Saim Selvi (Turkey, Ege University)
Farkhad Guseynov (Turkey, Bilkent University) Salih Shimshek (Turkey, Sakarya University)
Firuddin Semenderov (Azerbaijan, Baku State University) Sami Karahan (Turkey, Konya Selchuk University)
Gholam Riza Sabri Tabrizi (London, Edinburg Uni. King College) Shamil Samedzade (Azerbaijan, Technical University)
Gültekin Yildiz (Turkey, Sakarya University) Surkhay Akberov (Turkey, Yildiz Technical University)
Halit Pastaci (Turkey, Yildiz Technical University) Tabriz Aliev (Azerbaijan, Oil Academy)
Halil Gasimov (Azerbaijan, National Academy of Science) Tarlan Afandiyev (Belarus, National Academy of Science)
Hakan Acar (Turkey, Fatih University) Telman Aliyev (Azerbaijan, National Academy of Science)
Hilmi Kirlioglu (Turkey, Sakarya University) Tofiq Hajiyev (Azerbaijan, Baku State University)
James F. Rinehart (USA, Troy University) Tatyana Birshteyn (Russia, National Academy of Science)
Ibrahim El-Rabi (USA) Vasim Mammedaliev (Azerbaijan, Baku State University)
Irada Aliyeva (Azerbaijan, Baku State University) Vladimir Pashenko (Russia, Moskow State University)
Ismail Ozsoy (Turkey, Fatih University) Yaqub Mahmudov (Azerbaijan, National Academy of Science)
Kev Salihov (Tataristan, Kazan University) Yusuf Tuna (Turkey, Istanbul University)
Konstantin Voldemarovich Shaitan (Russia, Moskow State Unıversıty) Zafer Ayvaz (Turkey, Ege University)
Design
Sahìb Kazimov
Corresponding Address
Journal of Qafqaz University
Baku - Sumqayit Road, 16 km., Khirdalan, Baku, AZ, Azerbaijan
Tel: 00 12 - 28 62/66 Fax: 00 12 28 61/67
e-mail: [email protected]
web: seafoodplus.info
The “Journal of Qafqaz University” is a publication of
Qafqaz University and issue twice a year since
Copyright © Qafqaz University
ISSN
Reyestr No: ,
Abonet
The Journal of Qafqaz University is available by subscription for 30 USD a year abroad and
AZN in Azerbaijan. Bankship and corresponding address must be faxed to Qafqaz University.
Bank Account: T.C. Ziraat Bankasí / Üsküdar-Ìstanbul, Hesap Sahibi: Ömer Okumuå, Hesap Türü/Para Birimi: Vadesiz Hesap/TL
Hesap No: , IBAN: TR (Türkiye);
Qafqaz Universiteti: VÖEN: , Hesab No: AZN, USD, Kod: Müx. Hes.
“Texnikabank ASC” Abåeron Filialí - VÖEN: SWIFT BIC: TECIAZ22 (Azerbaijan)
ISSN
Qafqaz
Universiteti
Jurnalı
“Journal of Qafqaz University” beynəlxalq jurnalı Russian
Periodicals Catalog, Directory of Open Access Journals,
Middle East Virtual Library, The International Consortium for
the Advancement of Academic Publication, JournalSeek,
Genamics, RefSeek, Dspace, Eprınts, Indexcopernicus
beynəlxalq elmi indekslərinə daxildir.
T bi t Elml ri Seriyas
No 25,
Täsisçi
Ahmet Saniç
Baå Redaktor
Niftalí Qocayev
Näår Redaktoru
Elçin Süleymanov
Näår Redaksìyasí
Üzv Ìradä Äliyeva
Üzv Muharrem Kaplan
Üzv Murat Erguvan
Üzv Ìslam Hüseynov
Katib Ramil Hacíyev
Redaksìya Heyäti
Ahmet Öksüz Mämmädälì Babaålí
Ayhan Erdal Mehmet Ríhtím
Ali Bora Mustafa Akdað
Cihan Bulut Reha Yílmaz
Fäxräddìn Ìsayev Ömer Okumuå
Hämzaða Orucov Xälil Ìsmayílov
Mäslähät Heyäti
Əbdül Əziz Əbdül Hafis Əl Xouli (Misir, Qahirə Universiteti) Oqtay Qasımov (ABŞ, Kaliforniya Universiteti)
Əli Fuat Bilkan (Türkiyə, Ekonomi və Teknoloji Universiteti) Məhəmməd Təbrizi (ABŞ, East Carolina University)
Əjdər Ağayev (Azərbaycan, Təhsil Problemləri İnstitutu) Muhittin Şimşek (Türkiyə, Sakarya Universiteti)
Akif Hüseynli (Azərbaycan, Qafqaz Universiteti) Nadir Əlişov (Ukrayna, Elmlər Akademiyası)
Əli Çelik (Türkiyə, Karadeniz Teknik Universiteti) Nazan Bekiroğlu (Türkiyə, Karadeniz Teknik Universiteti)
Bəhram Əsgərov (Azərbaycan, Bakı Dövlət Universiteti) Nadir Seyidov (Azərbaycan, Milli Elmlər Akademiyası)
Don C. Hines (ABŞ, Troy Universiteti) Rasim Əliquliyev (Azərbaycan, Milli Elmlər Akademiyası)
Erol Oral (Qırğızıstan, Beynəlxalq Atatürk Alatoo Universiteti) Saim Selvi (Türkiyə, Ege Universiteti)
Erhan Birgili (Türkiyə, Sakarya Universiteti) Salih Şimşek (Türkiyə, Sakarya Universiteti)
Fərhad Hüseynov (Türkiyə, Bilkənt Universiteti) Sami Karahan (Türkiyə, Konya Selcuk Universiteti)
Firuddin Səməndərov (Azərbaycan, Bakı Dövlət Universiteti) Şamil Səmədzadə (Azərbaycan, Texniki Universitet)
Gholam Rıza Sabri Təbrizi (London, Edinburg Univ., King College) Surxay Əkbərov (Türkiyə, Yıldız Teknik Universiteti)
Gültəkin Yıldız (Türkiyə, Sakarya Universiteti) Təbriz Əliyev (Azərbaycan, Neft Akademiyası)
Halit Pastacı (Türkiyə, Yıldız Teknik Universiteti) Tofiq Hacıyev (Azərbaycan, Bakı Dövlət Universiteti)
Hakan Acar (Türkiyə, Fatih Universiteti) Tərlan Əfəndiyev (Belarusiya, Elmlər Akademiyası)
Hilmi Kırlıoğlu (Türkiyə, Sakarya Universiteti) Telman Əliyev (Azərbaycan, Milli Elmlər Akademiyası)
James F. Rinehart (ABŞ, Troy Universiteti) Tatyana Birshteyn (Rusiya, Rusiya Elmlər Akademiyası)
İbrahim Əl-Rabi (ABŞ) Vasim Məmmədəliyev (Azərbaycan, Bakı Dövlət Universiteti)
İradə Əliyeva (Azərbaycan, Bakı Dövlət Universiteti) Vladimir Paşenko (Rusiya, Moskva Dövlət Universiteti)
İsmail Özsoy (Türkiyə, Fatih Universiteti) Xəlil Qasımov (Azərbaycan, Milli Elmlər Akademiyası)
Kev Salihov (Tatarıstan, Kazan Universiteti) Yaqub Mahmudov (Azərbaycan, Milli Elmlər Akademiyası)
Konstantin Voldemaroviç Şaitan (Rusiya, Moskva Dövlət Universiteti) Yusuf Tuna (Türkiyə, İstanbul Universitesi)
Lətif Hüsynov (Azərbaycan, Milli Məclis) Zafer Ayvaz (Türkiyə, Ege Universiteti)
Tärtibat
Sahìb Kazímov
Ünvan
“Journal of Qafqaz University”
AZ, Baký -Sumgayýt yolu, cý km., Xýrdalan - Baký / Azärbaycan
Tel: 00 12 - 28 62/66 Fax: 00 12 28 61/67
e-mail: [email protected]
web: seafoodplus.info
“Journal of Qafqaz University” jurnalí Qafqaz Unìversìtetìnìn näårìdìr;
ci il tarixindän etibarän ìldä ìkì däfä därc edìlìr.
Copyright © Qafqaz University
ISSN -
Reyest: No: ,
Abunä
Jurnalín illik abunä qiymäti 9 manat 20 qäpik olub, Azärbaycan xaricindä 30 ABÅ Dollarídír. Abunä olmaq istäyänlärin abunä
qiymätini aåagídakí hesaba köçürüb, qäbzin bir nüsxäsini älaqä ünvaní ilä birlikdä Qafqaz Universitetinä fakslamalarí lazímdír.
Bank Hesabí: T.C. Ziraat Bankasí / Üsküdar-Ìstanbul, Hesap Sahibi: Ömer Okumuå, Hesap Türü/Para Birimi: Vadesiz Hesap/TL
Hesap No: , IBAN: TR (Türkiye);
Qafqaz Universiteti: VÖEN: , Hesab No: AZN, USD, Kod: Müx. Hes.
“Texnikabank ASC” Abåeron Filialí - VÖEN: SWIFT BIC: TECIAZ22 (Azärbaycan)
ISSN
Qafqaz
Üniversitesi
Dergisi
“Journal of Qafqaz University” Uluslararası Dergisi Russian
Periodicals Catalog, Directory of Open Access Journals,
Middle East Virtual Library , The International Consortium
for the Advancement of Academic Publication, JournalSeek,
Genamics, RefSeek, Dspace, Eprınts, Indexcopernicus
uluslararası bilimsel endeksler tarafından taranmaktadır.
Baå Editör
Niftalí Gocayev
Yayín Editörü
Elçin Süleymanov
Yayín Editörlüðü
Üye Ìrade Aliyeva
Üye Muharrem Kaplan
Üye Murat Erguvan
Üye Ìslam Hüseynov
Sekreter Ramil Hacíyev
Yayín Kurulu
Ahmet Öksüz Halil Ìsmayílov
Ayhan Erdal Memmedalì Babaålí
Ali Bora Mehmet Ríhtím
Cihan Bulut Mustafa Akdað
Fahrettìn Ìsayev Reha Yílmaz
Hämzaða Orucov Ömer Okumuå
Daníåma Kurulu
Abdul Aziz Abdul Hafis El Houli (Mısır, Kahire Üniversitesi) Latif Hüseynov (Azerbaycan, Milli Meclis)
Ali Fuat Bilkan (Türkiye, Ekonomi ve Teknoloji Üniversitesi) Muhammed Tebrizi (ABD, East Carolina University)
Ejder Ağayev (Azerbaycan, Eğitim Problemleri Enstitüsü) Muhittin Şimşek (Türkiye, Sakarya Üniversitesi)
Akif Hüseynli (Azerbaycan, Milli İlmler Akademisi) Nadir Alişov (Ukrayna, İlmler Akademisi)
Ali Çelik (Türkiye, Karadeniz Teknik Üniversitesi) Nazan Bekiroğlu (Türkiye, Karadeniz Teknik Üniversitesi)
Behrem Askerov (Azerbaycan, Bakü Devlet Üniversitesi) Nadir Seyidov (Azerbaycan, Milli İlimler Akademisi)
Don C. Hines (ABD, Troy Üniversitesi) Rasim Alikuliyev (Azerbaycan, Milli İlimler Akademisi)
Erol Oral (Kırgızistan, Uluslararası Atatürk Alatoo Üniversitesi) Saim Selvi (Türkiye, Ege Üniversitesi)
Erhan Birgili (Türkiye, Sakarya Universitesi) Salih Şimşek (Türkiye, Sakarya Üniversitesi)
Ferhat Hüseynov (Türkiye, Bilkent Üniversitesi) Sami Karahan (Türkiye, Konya Selçuk Üniversitesi)
Firuddin Semenderov (Azerbaycan, Bakü Devlet Üniversitesi) Şamil Samedzade (Azerbaycan, Teknik Üniversite)
Gholam Rıza Sabri Tebrizi (London, Edinburg Uni. King College) Surhay Ekberov (Türkiye, Yıldız Teknik Üniversitesi)
Gültekin Yıldız (Türkiye, Sakarya Üniversitesi) Tebriz Aliyev (Azerbaycan, Neft Akademisi)
Oktay Kasımov (ABD, Kaliforniya Üniversitesi) Tofiq Hacıyev (Azerbaycan, Bakü Devlet Üniversitesi)
Halit Pastacı (Türkiye, Yıldız Teknik Üniversitesi) Terlan Efendiyev (Belarusya, İlimler Akademisi)
Hakan Acar (Türkiye, Fatih Üniversitesi) Telman Aliyev (Azerbaycan, Milli İlimler Akademisi)
Hilmi Kırlıoğlu (Türkiye, Sakarya Üniversitesi) Tatyana Birshteyn (Rusiya, Rusiya İlimler Akademisi)
James F. Rinehart (ABD, Troy Üniversitesi) Vasim Memmedaliyev (Azerbaycan, Bakü Devlet Üniversitesi)
İbrahim El-Rabi (ABD) Halil Kasımov (Azerbaycan, Milli İlimler Akademisi)
İrade Aliyeva (Azərbaycan, Bakı Dövlət Universiteti) Vladimir Paşenko (Rusya, Moskova Üniversitesi)
İsmail Özsoy (Türkiye, Fatih Üniversitesi) Yaqub Mahmudov (Azerbaycan, Milli İlimler Akademisi)
Kev Salihov (Tataristan, Kazan Üniversitesi) Yusuf Tuna (Türkiye, İstanbul Üniversitesi)
Konstantin Voldemaroviç Şaitan (Rusya, Moskova Devlet Üniversitesi) Zafer Ayvaz (Türkiye, Ege Üniversitesi)
Dizgi
Sahìb Kazímov
Yazíåma Adresi
“Journal of Qafqaz University”
AZ, Baký -Sumgayýt yolu, km., Xýrdalan - Baký / Azerbaycan
Tel: 00 12 - 28 62/66 Fax: 00 12 28 61/67
e-mail: [email protected]
web: seafoodplus.info
“Journal of Qafqaz University” dergisi Qafqaz Üniversitesi Yayímídír;
senesinden itibaren yílda iki defa yayímlanír.
Copyright © Qafqaz University
ISSN —
Reyest: No ,
Abone
Derginin yıllık bedeli Yeni Azerbaycan manatı olup Azerbaycan dışı için 30 ABD Dolarıdır. Abone olacakların abone bedelini
aşağıdaki hesaba yatırıp dekont fotokopisini haberleşme adresi ile beraber Qafqaz Üniversitesi'ne fakslamaları gerekmektedir.
Banka Hesabí: T.C. Ziraat Bankasí / Üsküdar-Ìstanbul, Hesap Sahibi: Ömer Okumuå, Hesap Türü/Para Birimi: Vadesiz Hesap/TL
Hesap No: , IBAN: TR (Türkiye);
Qafqaz Üniversitesi: VÖEN: , Hesab No: AZN, USD, Kod: Müx. Hes.
“Texnikabank ASC” Abåeron Filialí - VÖEN: SWIFT BIC: TECIAZ22 (Azärbaycan)
ISSN
Журнал
Университета
Кавказ
Журнал “Journal of Qafqaz University” входит в Российский
периодический каталог, Directory of Open Access Journals,
Middle East Virtual Library, The International Consortium for the
Advancement of Academic Publication, JournalSeek, Genamics,
RefSeek, Dspace, Eprints, Indexcopernicus.
Серия Естествознания
и Техники
No 25,
Учредитель
Ахмед Санич
Редактор
Нифтали Годжаев
Издательский Совет
Члены Ирада Алиева
Члены Мугaррам Кaплан
Члены Мурат Эргуван
Члены Иcлам Гусейнов
Секретарь Рамиль Гаджиев
Редакционная Коллегия
Ахмет Оксуз Мамедали Бабашлы
Айхан Ердал Мехмeт Рыхтым
Али Бора Муcтaфa Aкдaг
Джихан Булут Рехa Йылмaз
Фахреддин Исаев Омaр Окумуш
Гамзага Oруджов Xалил Исмаилов
Дизайн
Сахиб Казымов
Адрес
«Journal of Qafqaz University»
AZ, Шоссе Баку–Сумгаит, 16 км, Хырдалан - Баку / Азербайджан
Teл: 00 12 - 28 62/66 Faкс: 00 12 28 61/67
e-mail: [email protected]
web: seafoodplus.info
Журнал «Journal of Qafqaz University» издание
Университета Кавказ, публикуется два раза в год с года
Copyright © Qafqaz University
ISSN -
Reyest: No: ,
Абонент
Годовая абонентская плата AZN, за рубежом 30 $ (USD). Абоненты должны перечислить
деньги на нижеследующие счета и выслать нам по факсу обратный адресс и счет фактуру.
Банковские Счета: T.C. Ziraat Bankasí / Üsküdar-Ìstanbul, Hesap Sahibi: Ömer Okumuå, Hesap Türü/Para Birimi: Vadesiz Hesap/TL
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Qafqaz Üniversitesi: VÖEN: , Hesab No: AZN, USD, Kod: Müx. Hes.
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Journal of Qafqaz University
An International Journal
Contents
Physics and technics 1
Структурно‐функциональная взаимосвязь кардиоактивных пептидов,
миелопептидов и гликопептидов
Л. И. Исмаилова 3
Nano‐porous silicon for gas sensor and fuel cell applications
Tayyar Dzhafarov, Sureyya Aydın Yuksel 20
İkiölçülü dalğa tənliyinin qrup nəzəriyyəsi metodu ilə tədqiqi
Ə.Q. Ağamalıyev 36
Kompleks konsantrelerdeki bakır ve çinkonun selektif çözeltme
imkânları üzerine bir araştırma
Mustafa Akdağ 40
About structural changes in polyethylene glycol ‐ C4O6H4Na2 ‐ water two‐phase system
E.A. Masimov, H.F. Abbasov, T.O. Bagirov 46
Heptapeptid molekulunun nəzəri konformasiya analizi
N.A. Əhmədov, R.M. Abbaslı, E.M.Həsənov 49
Ser‐Pro‐Leu‐Gly‐Thr‐Met‐Arg‐Phe‐Nh2 molekulunun fəza quruluşu
N.A.Əhmədov, seafoodplus.infoı, İ.T.Məmmədova, Şseafoodplus.infoıyeva 54
Определение сечения когерентного рассеяния нейтронов на
кристаллах изотопов лития, углерода и никеля кодом MCNP4C
Масти. Д 58
Эффект заполнения зон в кристаллах Gase при
высоких уровнях оптического возбуждения
А.А. Салманова 64
Электронно‐конформационные свойства молекулы вилон
Л.С. Гаджиева, Л.И. Исмаилова 69
Депонирование и транспорт оксида азота в биологических системах
И.С. Курбанов 76
Toz metalürjisi ile üretilmiş iki metal parçanın difüzyon kaynağıyla
birleştirilmesinde sıcaklığın kaynak bölgesine etkisinin irdelenmesi
Yadullah Babayev 92
Конформационные свойства молекулы антимикробного пептида тритрптицина
Г.А. Агаева, Р.Э. Алиев
Обобщение экспериментальных данных по изобарной объемной теплоемкости
бинарных растворов метанола и изоспиртов
Махир Баширов, Яшар Назиев, Акиф Бахшиев
Электронное строение мономерных и димерных
комплексов молекулы карнозина с цинком
С.Д. Демухамедова, И.Н. Алиева, Н.М. Годжаев, Н.С. Набиев
Mathematics
New inequalities on triangle areas
Y.N. Aliyev
Лифты векторных полей в полутензорное расслоение типа (2,0)
Габил Фаттаев
Об отображении двумерных евклидовых пространств
Наджаф Ягуб оглы Алиев
Journal of Qafqaz University
An International Journal
№: 25,
Texniki Elmlər
İçindəkilər
Fizika və Texnika 1
Структурно‐функциональная взаимосвязь кардиоактивных пептидов,
миелопептидов и гликопептидов
Л. И. Исмаилова 3
Nano‐porous silicon for gas sensor and fuel cell applications
Tayyar Dzhafarov, Sureyya Aydın Yuksel 20
İkiölçülü dalğa tənliyinin qrup nəzəriyyəsi metodu ilə tədqiqi
Ə.Q. Ağamalıyev 36
Kompleks konsantrelerdeki bakır ve çinkonun selektif çözeltme
imkânları üzerine bir araştırma
Mustafa Akdağ 40
About structural changes in polyethylene glycol ‐ C4O6H4Na2 ‐ water two‐phase system
E.A. Masimov, H.F. Abbasov, T.O. Bagirov 46
Heptapeptid molekulunun nəzəri konformasiya analizi
N.A. Əhmədov, R.M. Abbaslı, E.M.Həsənov 49
Ser‐Pro‐Leu‐Gly‐Thr‐Met‐Arg‐Phe‐Nh2 molekulunun fəza quruluşu
N.A.Əhmədov, seafoodplus.infoı, İ.T.Məmmədova, Şseafoodplus.infoıyeva 54
Определение сечения когерентного рассеяния нейтронов на
кристаллах изотопов лития, углерода и никеля кодом MCNP4C
Масти. Д 58
Эффект заполнения зон в кристаллах Gase при
высоких уровнях оптического возбуждения
А.А. Салманова 64
Электронно‐конформационные свойства молекулы вилон
Л.С. Гаджиева, Л.И. Исмаилова 69
Депонирование и транспорт оксида азота в биологических системах
И.С. Курбанов 76
Toz metalürjisi ile üretilmiş iki metal parçanın difüzyon kaynağıyla
birleştirilmesinde sıcaklığın kaynak bölgesine etkisinin irdelenmesi
Yadullah Babayev 92
Конформационные свойства молекулы антимикробного пептида тритрптицина
Г.А. Агаева, Р.Э. Алиев
Обобщение экспериментальных данных по изобарной объемной теплоемкости
бинарных растворов метанола и изоспиртов
Махир Баширов, Яшар Назиев, Акиф Бахшиев
Электронное строение мономерных и димерных
комплексов молекулы карнозина с цинком
С.Д. Демухамедова, И.Н. Алиева, Н.М. Годжаев, Н.С. Набиев
Riyaziyyat
New inequalities on triangle areas
Y.N. Aliyev
Лифты векторных полей в полутензорное расслоение типа (2,0)
Габил Фаттаев
Об отображении двумерных евклидовых пространств
Наджаф Ягуб оглы Алиев
Journal
of
Qafqaz
University
PHYSICS AND TECHNICS
FİZİKA VƏ TEXNİKA
FİZİK VE TEKNİK
ФИЗИКА И TEXHИКА
СТРУКТУРНО‐ФУНКЦИОНАЛЬНАЯ ВЗАИМОСВЯЗЬ
КАРДИОАКТИВНЫХ ПЕПТИДОВ, МИЕЛОПЕПТИДОВ И
ГЛИКОПЕПТИДОВ
Л. И. ИСМАИЛОВА
Институт Физических Проблем,
Бакинский Государственный Университет
Баку / АЗЕРБАЙДЖАН
[email protected]
РЕЗЮМЕ
STRUCTURE‐FUNCTIONAL RELATIONSHIP OF THE CARDIO ACTIVE PEPTIDES,
MYELOPEPTIDES AND GLYCOPEPTIDES
ABSTRACT
The spatial structure of the cardioactive peptides, myelopeptides and glycopeptides were investigated using
method of molecular mechanics. By theoretical conformational analysis method has been investigated the low‐
energy conformations, geometric and energetic parameters of these molecules.
Key words: peptide, conformation, structure, molecule
Number 25, 3
Л. И. Исмаилова
4 Journal of Qafqaz University
Структурно‐Функциональная Взаимосвязь Кардиоактивных Пептидов, Миелопептидов и Гликопептидов
цепи χ1, χ2, χ При этом индекс 1 ется метод теоретического конформа‐
соответствует значению угла χ в области ционного анализа, который позволяет с
0 −º, 2 − − ‐º, 3 − ‐ − 0º. Отсчет достаточной точностью количественно
двугранных углов вращения проводился описать геометрию молекулы и энергию
согласно стандартной номенклатуре взаимодействия атомов в этой молекуле
IUPAC‐IUB [11]. или между молекулами. Он исходит из
Известно, что пептидные молекулы по‐ механической модели, рассматриваю‐
лифункциональны. Это обусловлено тем, щей молекулу как систему взаимодейс‐
что пространственное строение этих мо‐ твующих атомов, при этом полностью
лекул может принимать в физиологи‐ абстрагируясь от электронов и ядер.
ческих условиях ограниченный набор ст‐ Поэтому метод теоретического конфор‐
руктур. В данной работе для нахожде‐ мационного анализа еще называют ме‐
ния пространственного строения пеп‐ тодом молекулярной механики.
тидных молекул использован теорети‐ Расчет выполнялся в рамках механичес‐
ческий подход, предложенный Поповым кой модели молекул с учетом невалент‐
Е.М.[2, 6, 10]. Этот подход позволяет ных, электростатических, торсионных
решить структурно‐функциональную за‐ взаимодействий и энергии водородных
дачу, разделив ее на несколько этапов: связей. Невалентные взаимодействия
1. Структурный этап–нахождение прос‐ оценивались по потенциалу Леннарда‐
транственной структуры и конформа‐ Джонса с параметрами Скотта и Шераги
ционной динамики пептидной молеку‐ [12]. Электростатические взаимодействия
лы на основании известной аминокис‐ рассчитывались в монопольном прибли‐
лотной последовательности. Использо‐ жении по закону Кулона c с использова‐
вание метода теоретического конформа‐ нием зарядов, предложенных в работе
ционного анализа позволяет по извест‐ [13]. Конформационные возможности
ной химической структуре найти пол‐ пептидов рассчитывались применитель‐
ный набор низкоэнергетических, биоло‐ но к условиям водного окружения, по‐
гически активных конформаций. этому величина диэлектрической про‐
2. Структурно‐функциональный этап– ницаемости принята равной Водо‐
конструирование искусственных анало‐ родные связи, которые оценивались по
гов, пространственное строение которых потенциалам типа Морзе, предполага‐
отвечает набору низкоэнергетических лись ослабленными (максимальная энер‐
конформаций природных пептидных гия образования водородной связи при
молекул. Этот этап позволяет связать ст‐ ro=1,8Å составляла 1,5 ккал/моль). Тор‐
руктуру молекулы с выполняемой функ‐ сионные потенциалы и величины барье‐
цией. ров вращения аналогичны величинам,
3. Этап количественной оценки биоло‐ предложенным в работах [12, 14].
гической активности пептидных моле‐
кул, оценки участков связывания с ре‐ II. Кардиоактивные пептиды.
цептором и сопоставления теоретичес‐ Был проведен расчет пространственной
ких результатов расчетов пространствен‐ структуры молекул кардиоактивных пеп‐
ной структуры пептидных молекул с из‐ тидов, относящихся к классу нейропеп‐
вестными экспериментальными данными. тидов [15‐21]. Выбор объектов исследова‐
Для определения пространственной ст‐ ния был продиктован их актуальностью,
руктуры пептидных молекул использу‐ так как по данным Всемирной организа‐
Number 25, 5
Л. И. Исмаилова
6 Journal of Qafqaz University
Структурно‐Функциональная Взаимосвязь Кардиоактивных Пептидов, Миелопептидов и Гликопептидов
Таблица 1. Шейпы, оптимальные конформации, энергетические вклады невалентных, электростатических,
торсионных взаимодействий нонапептидной молекулы Мet1‐Met9‐NH2
Number 25, 7
Л. И. Исмаилова
Рис Пространственная структура шейпов eeeffeff, eefefeee, fffefeff молекулы нонапептида Мet1‐Met9‐NH2
8 Journal of Qafqaz University
Структурно‐Функциональная Взаимосвязь Кардиоактивных Пептидов, Миелопептидов и Гликопептидов
Остаток Шейп
eeeffeff eefefeee ffffeeff
Met1 ‐ ‐ ‐47 ‐55
‐67 ‐ ‐67 ‐ ‐
Asn2 ‐96 ‐ ‐97 ‐ ‐69 ‐57 ‐
‐ 83 ‐ 91 91
Tyr3 ‐ ‐98 ‐54 ‐79 ‐53
58 89 ‐60 92 ‐59 99
Leu4 ‐96 ‐63 ‐ ‐ ‐ ‐
‐60 ‐ 64 64
Ala5 ‐86 ‐56 ‐87 ‐52 ‐ ‐86 ‐53 ‐
Phe6 ‐ ‐86 ‐ ‐
49 89 ‐ 84 48 89
Pro7 ‐64 ‐ ‐61 ‐
Arg8 ‐ ‐59 ‐ 98 ‐ ‐61 ‐
‐62 ‐66 ‐ ‐ ‐66 ‐67 ‐ ‐ ‐63 ‐66 ‐ ‐
Met9 ‐ ‐36 ‐ ‐ ‐35
‐ ‐68 ‐69 ‐ ‐58 ‐60
Uотн, ккал/моль 0 0,7 1,8
Таблица 3. Относительная энергия (ккал/моль) конформаций молекулы Мet1‐Met9‐NH2 и ее аналогов
Number 25, 9
Л. И. Исмаилова
10 Journal of Qafqaz University
Структурно‐Функциональная Взаимосвязь Кардиоактивных Пептидов, Миелопептидов и Гликопептидов
Number 25, 11
Л. И. Исмаилова
12 Journal of Qafqaz University
Структурно‐Функциональная Взаимосвязь Кардиоактивных Пептидов, Миелопептидов и Гликопептидов
Number 25, 13
Л. И. Исмаилова
14 Journal of Qafqaz University
Структурно‐Функциональная Взаимосвязь Кардиоактивных Пептидов, Миелопептидов и Гликопептидов
Таблица 5. Низкоэнергетические конформации миелопептидов
Молекула Uотн Аминокислотная последовательность Конформация
МП‐1 0,0 Phe‐Leu‐Gly‐Phe‐Pro‐Thr‐NH2 R2B21PB2RR11 (fffef)
2,3 R2R21RB3RR11 (fffef)
6,9 B1B21PB3RR11 (effef)
4,5 B1B21PB3 BB31 (effee)
МП‐2 0,0 Leu‐Val‐Val‐Tyr‐Pro‐Trp‐NH2
4,1 R21R2R2B1RR11 (fffef)
R21B2B2B3RR13 (feeef)
МП‐3 0,0 Leu‐Val‐Cys‐Tyr‐Pro‐Gln‐NH2 R21R2R2B1RR (fffef)
5,4 R21R2R2B3BB (fffee)
Number 25, 15
Л. И. Исмаилова
рами среди других структур. Можно онные возможности этих боковых при‐
предположить, что связь миелопепти‐ весков, мы построили ряд конформа‐
дов с Т‐лимфоцитами осуществляется ционных карт при варьировании одного
именно посредством этих структур. В или двух строго определенных углов
пользу этого говорит тот факт, что боко‐ молекулы моносахарида.
вые цепи Phe4 и Tyr4 в низкоэнергети‐
Следует отметить, что N‐ацетильная
ческих структурах обращены в раствори‐
группа и СН2ОН группа находятся по
тель и конформационно свободны. разные стороны от сахарного кольца,
Следует подчеркнуть, что в настоящее поэтому они влиять на конформацион‐
время молекулы миелопептидов пред‐ ные состояния друг друга не могут.
ставляют большой интерес для широ‐ Отсюда следует, что из–за удаленности
кого исследования [28‐33]. эти боковые привески не влияют на кон‐
формационные карты друг друга. При
IV. Гликопептиды. построении конформационных карт од‐
ной группы, положение другой группы
Известно, что биологическая активность
фиксировалось в оптимальных конфор‐
гликанов и гликопептидов существенно
мациях. Конформационный анализ сво‐
зависит от числа и способа присоедине‐
бодного N‐ацетил глюкозамина, постро‐
ния остатков глюкозы, от типа и стерео‐
ение конформационных карт позволил
химии аминокислот, образующих пеп‐
найти два значения угла Q2g (‐30˚, 20˚)
тидные части молекул. Исследования
для N‐ацетильной группы. Для СН2ОН
функциональной активности этих моле‐
группы значения углов Q5,6g= 60, , ‐60˚
кул обнаружили их высокую иммуно‐
оказались равновероятными.
стимулирующую и противоопухолевую
активность. Поэтому нами сначала был Низкоэнергетические положения остат‐
выполнен конформационный анализ ка D‐молочной кислоты в молекуле N‐
олигосахаридных молекул, так как они ацетил‐мурамовой кислоты были найде‐
являются ингибиторами и субстратами ны из конформационных карт Qm 3‐ φm
фермента лизоцима и входят в состав и φm ‐ ψm. Для молекулы MurNAc из
гликопептидных молекул, представляю‐ карты φm ‐ ψm были определены пять
щих большой научный интерес. Были низкоэнергетических конформаций, от‐
изучены пространственные структуры личающиеся значениями двугранных уг‐
моно‐, ди‐, тетрасахаридных молекул, лов лактильной группы. Первые две
содержащих N‐ацетил‐глюкозамин отвечают состоянию угла Qm 3=‐30º, а
(GlcNAc) и N‐ацетил‐мурамовую кисло‐ остальные три конформации – состоя‐
ту (MurNAc). нию с Qm3= 0º.
Сначала были изучены конформацион‐ Биологическая активность гликанов и
ные свойства свободной молекулы моно‐ гликопептидных молекул зависит от
сахарида. У молеклы (GlcNAc) имеется числа и способа присоединения остат‐
два боковых привеска, положения кото‐ ков глюкозы, от стереохимии амино‐
рых в пространстве определяются сле‐ кислот в пептидных частях молекул. Экс‐
дующими двугранными углами: поло‐ периментальные исследования функци‐
жение N‐ацетильной группы определя‐ ональной активности гликопептидных
ется двугранным углом Q2g и положение молекул обнаружили их высокую имму‐
группы СН2ОН определяется углами Q5g ностимулирующую и противоопухоле‐
и Q6g.. Чтобы определить конформаци‐ вую активность (табл.6). Важно было со‐
16 Journal of Qafqaz University
Структурно‐Функциональная Взаимосвязь Кардиоактивных Пептидов, Миелопептидов и Гликопептидов
Таблица 6. Адьювантная и противоопухолевая активность гликопептидов
№ Гликопептидная Противо Адьювантная
Молекула опухолевая активность
активность
1 GlcNAc‐MurNAc‐LAla‐DGluNH2 + + + +++
2 GlcNAc‐MurNAc‐DAla‐DGluNH2 + + +
3 GlcNAc‐MurNAc‐LAla‐LGluNH2 ― ―
4 GlcNAc‐MurNAc‐LAla‐DAspNH2 + ―
5 MurNAc‐LAla‐DGluNH2 + + ++
6 MurNAc‐LAla‐LGluNH2 ― ―
7 MurNAc‐DAla‐DGluNH2 + ―
8 MurNAc‐LAla‐DAspNH2 ― ―
9 GlcNAc‐MurNAc‐Lala + ―
10 GlcNAc‐MurNAc ― ―
11 MurNAc ― ―
12 LAla‐DGluNH2 ― ―
По‐видимому, причина снижения актив‐ сутствует. Из этого можно сделать вывод,
ности соединений с D‐Asp кроется в са‐ что аминокислота D‐Glu в наиболее ак‐
мой природе их взаимодействия с ре‐ тивной молекуле GlcNAc–MurNAc‐L‐Ala‐
цептором. Слабо выраженным противо‐ D‐GluNH2, вероятно, не принимает не‐
опухолевым действием обладает и гли‐ посредственное участие в реакции, а
копептид GlcNAc–MurNAc‐L‐Ala, в кото‐ служит для понижения активационного
ром остаток глутаминовой кислоты от‐ барьера. То же можно сказать относи‐
Number 25, 17
Л. И. Исмаилова
18 Journal of Qafqaz University
Структурно‐Функциональная Взаимосвязь Кардиоактивных Пептидов, Миелопептидов и Гликопептидов
Number 25, 19
NANO‐POROUS SILICON FOR GAS SENSOR AND
FUEL CELL APPLICATIONS
Tayyar DZHAFAROV
Institute of Physics,
Azerbaijan National Academy of Sciences,
Baku / AZERBAIJAN
[email protected]
Sureyya Aydın YUKSEL
Department of Physics,
Yildiz Technical University,
Esenler – Istanbul / TURKEY
ABSTRACT
The hydrogen fuel cell has recently attracted attention as a clear source for the future. For this reason, there is
a big demand for reliable and inexpensive hydrogen gas sensors. The nanoporous silicon with a sponge‐like
structure and very large surface‐to‐ volume ration (about to m2/cm3) is attractive for gas sensor and
hydrogen fuel cell applications. In the paper the review of works on fabrication, structure, electrical and optical
properties of porous silicon (PS) is given. The operating principles of different types of gas sensors and hydrogen
fuel cells, specifically Proton Exchange Membrane type cell, were presented. New type sensor, based on metal/PS
Schottky‐type structures and working at room temperature without any power source was considered. Such
structures in the hydrogen‐containing atmosphere produce electricity by themselves, i.e. they exhibit the
properties of both a gas sensor and a hydrogen fuel cell.
Key words: porous silicon, gas sensor, hydrogen fuel cell, metal/porous silicon structure
НАНО‐ПОРИСТЫЙ КРЕМНИЙ ДЛЯ ГАЗОВЫХ СЕНСОРОВ И
ВОДОРОДНЫХ ТОПЛИВНЫХ ЭЛЕМЕНТОВ
РЕЗЮМЕ
Водородные топливные элементы привлекают внимание как источники чистой энергии будущего.
Поэтому имеется большая потребность в разработке надежных и недорогих газовых сенсоров, чувстви‐
тельных к водороду. Нано‐пористый кремний с ʺгубчатойʺ структурой и очень большим соотношением
площади поверхности пор к объему образца (около м2/см3) очень подходит для изготовления газовых
сенсоров и водородных элементов. В статье дан обзор данных по изготовлению, структуре и свойствам
пористого кремния. Рассмотрены принципы работы существующих типов газовых сенсоров и водородных
элементов, особенно PEM‐типа элемента. Представлен новый тип газового сенсора, основанного на метал/
пористый кремний барьерной структуре, который работает при комнатной температуре и без внешнего
источника энергии. Такой прибор сам генерирует электричество в водородной атмосфере, т.е. проявляет
свойства и газового сенсора, и водородного элемента.
Ключевые слова: пористый кремний, газовый сенсор, водородный элемент, метал/пористый кремний
структуры
mical etching have been know for many
I. Introduction
years [34,35] in However, it has been
Porous silicon (PS) layers formed on mono‐ extensively studied in last twenty years. In
crystalline silicon substrates by electroche‐ Canham reported the discovery signi‐
20 Journal of Qafqaz University
Nano‐Porous Silicon for Gas Sensor and Fuel Cell Applications
ficant visible photoluminscence from porous (defects and impurities) in the surrounding
silicon under UV illumination [7]. Fig. 1 SiOx layers [29].
illustrates the typical red luminescence of a
Quantum wires, quantum dots and quantum
porous silicon layer which was prepared
wells are basis of many modern devices
by a remarkable simple electrochemical
and they are the key to the development of
etching process on silicon wafer. The pho‐
the nanoelectronics. Electrochemical etching
toluminescence characteristics of porous
of Si results in the formation of nano‐
silicon in comparison to bulk mono‐
crystalline Si. The crystalline structure of
crystalline silicon and other silicon‐based
porous silicon presents a network of silicon
compounds is also given in Fig. 1. Typical
in nano‐sized regions surrounded by void
photoluminescence intensity of porous
space with a very large surface‐to‐volume
silicon in the visible region (‐ eV) is
ration (up to m2cm‐3) [21]. The structure
larger by several order of magnitude as
of porous silicon is like a sponge where
compared to the monocrystalline silicon,
quantum effects plays fundamental role (a
which locates in near infrared, correspon‐
quantum sponge) [5]. The pore surfaces are
ding to the eV energy of mono‐
covered by silicon hydrides and silicon
crystalline Si [33]. Si, being a indirect semi‐
oxides and therefore they are very chemical
conductor, is the dominant material of
active. These features of porous silicon (a
microelectronics. However, it a poor light
quantum system, a sponge structure and
emitter and therefore can not be used in
an extremely large pore surfaces) ensure
optoelectronics. Porous silicon prepared on
many possible applications, such as light
Si substrate, shows the high external
emitting diode, sensor, hydrogen fuel cell
efficiencies of photo‐and electrolumine‐
and other applications.
scence and suits for photonic applications.
However, the origin of photoluminescence Bellow the review of the crystalline struc‐
in PS is still controversial. A few models ture and properties of nano‐porous silicon,
are suggested for explanation mechanism and characterization of the porous silicon
of photoluminescence. According model based gas sensors and hydrogen fuel cells
proposed by Canham [7] radiative recom‐ have been presented.
bination of electron‐hole pairs occurs within
2. Preparation and Properties of Porous
nanometer silicon wires and their energy
Silicon
gaps become larger than that of bulk Si
(quantum confinement effect). This model Porous silicon layer on monocrystalline Si
modified by Koch et al. [24] suggests that substrate is usually formed by electro‐
electron‐hole pairs are photo‐excided in chemical etching of Si in HF: ethanol or
nanometer silicon particles and radiatively HF:H2O solution. Electrochemical etching
recombined via Si intrinsic surface states. of siliconis attractive because of the
Another model [6] suggests that lumine‐ possibility to tune the pore size from a few
scence from PS was caused by some special nanometers to a few tens of micrometers,
luminescence materials, such as SiHx com‐ just by choosing wafer doping level and
plexes, polysilanes, or SiO2 rather than an etching conditions. The simplest electro‐
intrinsic property of nanometer Si. A third chemical cell is shown in Fig. 2. The Si wafer
model believes that excitation of charge acts as the anode and the the platinum is
carriers occurs in nanometer silicon par‐ the cathode. The thickness of porous silicon
ticles and the photoexcitated carriers layer on Si substrate is determined by
transfer into the luminescence centers duration of etching. The porosity, i.e. the
Number 25, 21
Tayyar Dzhafarov, Sureyya Aydın Yuksel
voig fraction in the porous layer is deter‐ Si + 6HF →H2SiF6 + 4H+ +4e‐ (2)
mined by the current density (about 10‐
Pores, depending on the its diameter,
mA/cm2), composition electrolyte, resistivity
denoted as micropores (R<2nm), mesopores
and the doping density of Si substrate.
(2 nm < R < 50 nm) and macropores (R > 50
The anodic reaction on the Si substrate can nm). Under illumination the pore size
be written during pore formation as [4] dependent on doping density and anodi‐
zation conditions, with diameters in the
Si + 6HF →H2SiF6 + H2 + 2H+ +2e‐ (1)
range nm – 20 μm (macropores).
Silicon atoms are dissolved as SiF62‐ requires
PS layers with a thickness of 10‐20 μm and
the presence of F‐ ions (from HF solution)
an average porosity of 40 to 80% were
and positively charges holes (from the
silicon wafer) at the silicon interface. Con‐ prepared on n‐type () Si substrates (ρ=
centration of holes in p‐Si is sufficiently =1×10‐2 Ω cm) by anodic etching in HF:H2O
high (about – cm‐3) and this case = solution at a dc current of about 15
the nano‐size pores were formed. Concen‐ mA cm‐2 under white‐light illumination [8].
tration of holes in n‐Si is very small (about For some measurements, the PS films were
– cm‐3) and therefore generation of then detached from the Si substrate by
holes is possible due to illumination of n‐Si electro polishing in the same solution with
substrate. a current density of ‐ A cm‐2. The free
standing PS films were characterized by
The structure and size of pores in porous
porosity, thickness and resistivity measure‐
silicon layer formed on n‐Si substrate differ
ments. The average porosity was measured
from those for layer on p‐Si. If electroche‐
by a gravimetry technique. Resistivity and
mical etching was carried out at relatively
charge carrier concentration measurements
low current density (10‐80 mA/cm2), then
were carried out on the free standing PS
the local dissolution of silicon surface takes
layers attached to a dielectric substrate
place. Herewith, pore formation begins on
(glass) by using the Van der Pauw
surface defects of Si and further growth of
technique. In or In‐Ga alloy was used as an
pores into silicon substrate proceeds due to
ohmic contact to the PS layer. Morpholo‐
the holes diffusion to Si‐electrolyte interface.
gical characterizations of the PS surface
In the case of large current density ( –
were performed by scanning electron
A/cm2) when the amount of holes
microscopy.
moving to Si‐electrolyte interface is very
high, the etching of top regions of Si The average porosity, i.e. the avoid fraction
substrate is preferred. It ensures the unoform in the porous layer, can be obtained by
etching of silicon surface and formation a gravimetry using the equation
smooth surface of substrate (the so‐called P(%) ={ (m1 – m2)/(m1 – m3)} (3)
the electropolishing process). Raising the
current density above the critical value at Here m1 is Si sample mass before the
the end of anodization process results in a etching, m2 just after etching and m3 after
detachment of the porous silicon film from the removal of the porous layer by
Si substrates. The behavior at high current electropolishing or after a rapid dissolution
densities turns out to be useful to produce of the whole porous layer in a 3% KOH
porous silicon free‐standing layers. The solution.
anodic reaction during the electropolising One can also get the porous silicon layer
can be written as thickness d using the equation
22 Journal of Qafqaz University
Nano‐Porous Silicon for Gas Sensor and Fuel Cell Applications
d = (m1 – m3)/ρS (4)
eV with rising of porosity of PS films in the
range of 30‐90 % is observed. Data on Fig. 5
where ρ is the Si density ( g/cm3) and S
concerning a increase of the energy gap in
is the etched surface.
dependency on porosity of PS films, can be
Fig. 3 shows the SEM micrographs of explained by a model including the
porous silicon/Si structure. quantum confinement of carriers in the PS
The electrical measurements of the free microcrystallites, causing the widening of
the Si band gap.
standing PS layers with 65% porosity
( K, 45% RH) gave values of ρ = ×
Ω cm for resistivity, p = × cm‐3 for 3. Gas Sensors
hole concentration, and μ = cm2/(V s) A chemical sensor is defined as “a small
for hole mobility [9]. device that as the result of a chemical
Fig. 4 illustrate FTIR spectrum of free‐ interaction or process between the analyte
standing PS film of thickness 12 μm gas and the sensor device, transforms
measured at room temperature [10]. The chemical or biochemical information of a
peaks related with absorption on vibration quantitative or qualitative type into an
of Si‐H ( cm‐1) and Si‐O bonds ( analytically useful signal” [31]. Sensors have
cm‐1) located on pore surfaces were obser‐ been widely used for environmental moni‐
ved from Fig. 3. These bonds play an toring, industrial safety, homeland security,
important role in regulating optical, clinical diagnostics, automotive etc.
electrical and gas sensing properties of Gas sensors were divided on next main
porous silicon. The effect of isothermal categories: resistive, solid electrolyte, capa‐
annealing of free‐standing PS films on citive, infrared and other. The resistive sen‐
changes of absorption coefficient of Si‐H sors were based on Tin Oxide (SnO2) or
( cm‐1) and Si‐O ( cm‐1) peaks is similar metal oxide semiconductors (CuO,
used for estimation of diffusion coefficient WO,TiO2, ZnO, MgO). The working
from equation [1] principle of this type sensor is that the
Q = 2 π‐ SNo (Dt) (5) resistance of the metal oxide semicon‐
ductor changes when it is exposed to the
Here Q is the total quantity of hydrogen (or
ambient gas because the gas reacts with the
oxygen) penetrating from air into PS film
heated metal oxide surface and change its
(or out‐diffusing from PS film), No = N(0,t)
electronic properties. The sensor usually
is the surface concentration on an external
can be produced by coating a metal oxide
surface of PS film and S is the area of
layer on a substrate with two electrodes
sample. In the range of 65 – oC the
pre‐embedded on it. Metal oxide sensors
temperature dependence of hydrogen and
are commonly used for the detection of
oxygen diffusion coefficient along the
hazardous gases, such as NH3, CO, NO,
porous surfaces are described as [10]
etc. One limitation of metal oxide gas
D(H) = 5x10‐10 exp (‐ eV/kT) (6) sensors, however, is their high operating
D(O) = x10‐8 exp (‐ eV/kT) (7) temperature ( – oC) which leads to
high power consumption.
Fig. 5 shows energy gap in dependency on
porosity of the free standing PS films, The solid electrolyte gas sensor is similar to
calculated from extrapolation of the high semiconductor gas sensor but has voltage
energy part of (α2 ‐ hν) spectra [11]. Near output. Solid electrolyte sensor is typically
linear increase of band gap from to designed to operate at high temperature.
Number 25, 23
Tayyar Dzhafarov, Sureyya Aydın Yuksel
24 Journal of Qafqaz University
Nano‐Porous Silicon for Gas Sensor and Fuel Cell Applications
the adsorbed molecules or change in ties of the Au/PS structures were analysed
dielectric constent, as a result of gas con‐ by measuring the I‐V characteristics in the
densation inside the pores. dark, in daylight, and under tungsten‐
The large surface to volume ratio (about halogen lamp illumination mW cm‐2).
m2/cm3), high chemical reactivity at room All the investigated structures exhibited
temperature and potential compatibility very weak photosensitivity. The value of
with silicon integration technologies allow the open‐circuit photo voltage in daylight
to fabricate porous silicon based gas sensors. and under tungsten‐halogen lamp illumi‐
Below considered metal/porous silicon nation was 1‐3 mV. Therefore, gas‐sensitive
Schottky type structures operating at room measurements were performed under
temperature as humidity‐sensitive sensor daylight illumination.
or sensors sensitive to hydrogen‐containing The current‐voltage characteristics of Au/PS
gases, do not need to operate under external structure at the normal room conditions (45
voltage bias [8,9,10,11,12,13]. Instead, such %RH, T=K) showed rectifying proper‐
structures in hydrogen‐containing atmos‐ ties. Here the values of current under
phere produce electricity by themselve. In ‘forward’ voltages (the positive polarity on
other words, metal/PS structures exhibit Au film) are larger than those for ‘reverse’
the properties of both a gas sensor and a voltages. It is worth noting that the recti‐
hydrogen fuel cell. fying characteristics of Au‐PS structures as
Sensor fabrication. The Au/PS/Si structures well as Ag/PS [12] and Cu/PS structures [8]
were fabricated by the evaporation of a were depended on ambient humidity.
thin Au film onto the PS surface with a Herewith the reverse I‐V characteristics
porosity of 65% at room temperature by have more considerable humidity‐stimu‐
using the electron‐beam technique. The lated dependencies than the forward I‐V
thickness of the deposited Au film was characteristics.
nm, as obtained by measurements during The typical reverse I‐V characteristics of
the evaporation using a deposition Au/PS structure in air ambient at 45 %RH,
controller (Inficon, Leybold). Current‐ 70 %RH, 83 %RH, 90 %RH and 99 %RH
voltage (I‐V) characteristics, open‐circuit at room temperature are presented in
voltage (Voc), and short‐circuit current (Fig.7). It is seen that the reverse currents
density (Jsc) of the (Au)/PS/Si and PS/Si considerably increase with the rising of
structures were measured at room tempe‐ relative humidity. The value of current at
rature in air ( K, 45% relative humidity 99 %RH (for 2V) increases in comparison
(RH)) as well as for different gas atmos‐ with that at 45 %RH (for 2V) by factor It
pheres (humid, CO, and H2S) in the measu‐ will be noted that PS/Si structures (without
ring cell. The concentrations of CO and H2S Au film) showed a weak rectifying charac‐
were measured using a BW Defender teristics and the weak humidity‐sensitive
Multi‐Gas Detector. The gas‐stimulated properties.
open circuit voltage (Voc) and short‐circuit The humidity‐voltaic effect i.e. generation
current density (Jsc) for the contacts to the of a voltage between the contacts to Au
Au film and PS layer (or Si substrate) were film and PS layer under humidity expo‐
measured directly by a Thurlby‐ digital sition is observed for Au‐PS structures. The
multimeter. (Fig. 6). RH in the cell was similar effect is earlier discovered for
measured with an Extech‐ hygro Ag/PS and Cu/PS structures [8, 12]. Fig. 8
thermometer. The photosensitive proper‐ illustrates the open‐circuit voltage in
Number 25, 25
Tayyar Dzhafarov, Sureyya Aydın Yuksel
dependency on the relative humidity for tration of water molecules in air. The
one of such Au/PS structures. It is seen that voltage generated (about 30 mV), at a zero
the Voc approximately linearly increases concentration of CO gas is related to the
from 15 mV to mV with rise of the humidity of air. The relation between
relative humidity from 51 %RH to 95 %RH. open‐circuit voltage and H2S gas concen‐
The humidity‐sensitivity of Au/PS struc‐ tration is similar (Fig. 11) [9].
ture estimated from curve of Fig. 8 is about
The generation of Voc and Jsc was observed
10 mV/(%RH). The PS‐Si structures without
between the contacts to the Au film and PS
Au film on PS surface displayed the low
layer (or Si substrate), but not between the
value of Voc in humid atmosphere (about of
contacts to the PS layer and Si substrate. In
10 mV at 95%RH).
other words, the presence of the Au film on
The I‐V characteristics of the Au/PS/Si the porous Si is a necessary condition for
structure (thickness of PS film, 10 μm; the generation of electricity in the Au/PS/Si
surface area of Au film, cm2) in normal cell in humid, CO, and H2S atmospheres.
air ( K, 45% RH) and in the presence of The sensitivities of the Au/PS sensors to the
H2S gas are indicate good rectifying pro‐ humidity level and the concentrations of
perties (Fig.9). Also, the current under CO gas and H2S gas were about
reverse voltage (the negative polarity on mV/RH, mV/ppm, and mV/ppm,
the Au film) in the H2S atmosphere is a respectively.
factor of larger than that in air, while
the current under the forward voltage bias Fig. 12 shows the response‐recovery beha‐
in H2S is only times that in air. The vior of the open‐circuit voltage of the Au/PS
increased fragment of I‐V curve (2) in H2S sensor after successive cycles of placing the
is also shown in Fig. 9. The open‐circuit sensor in a H2S atmosphere (45 ppm). It can
voltage and short‐circuit current are be seen that the response time is about 60 s.
mV and mA, respectively. The small Sensitivity of Au/PS sensor to H2S gas (45
value of Isc may be caused by the high ppm) defined from the relation
internal electrical resistance of the Au/PS S={Voc(gas) – Voc(0)}/Voc (0) (8)
cell (about 4× Ω).
is equal Here Voc(gas) and Voc(0) are
The humidity/hydrogen‐containing gas ‐
the open‐circuit voltage for concentration
voltaic effect, i.e., the generation of the
of H2S gas 45 ppm and 0, respectively.
open‐circuit voltage between the contacts
to the Au film and PS (or Si) after an To summarize, the following experimental
increase in humidity (Fig. 8) or by adding a facts related to the change of the electrical
hydrogen‐containing gas [8, 9, 12, 13], was characteristics after placing the Au/PS
also observed for the Au/PS structure in Schottky‐type structures in a humid, CO,
CO and H2S atmospheres (Fig. 10 and Fig. or H2S gas atmosphere were solidly
11) [9]. Fig. 10 illustrates the dependence of established:
the open‐circuit voltage generated in Au/PS
(1) Placing the Au/PS structures in a humid,
structures on the CO concentration at 45
CO, or H2S gas atmosphere results in
and 58% RH. An almost linear increase of
the increase of both the forward and
Voc is observed with increasing CO
reverse currents, but the latter increase
concentration. Voc also increases with rising
is much greater.
RH. The increase of voltage at higher
humidity observed in Fig can be related (2) Simultaneously, the formation of an
to the influence of the increased concen‐ open‐circuit voltage (up to mV) and
26 Journal of Qafqaz University
Nano‐Porous Silicon for Gas Sensor and Fuel Cell Applications
a short‐circuit current (up to mA) the cathode (PS/Si interface) region. Water
was observed for these structures. molecules and oxygen from air can easily
penetrate into the PS/Si interface due to the
(3) However, when the PS/Si structures
imperfections in this area. Here the
(without Au film) were placed in a
hydrogen is recombined and reacts with
humid, CO, or H2S atmosphere, electri‐
oxygen to produce water molecules.
city generation was not observed.
Concerning the the operating principle of
(4) Voc is dependent on the relative humi‐
the Au/PS/Si sensor to detect the CO mole‐
dity and the concentration of CO and
cules, one can suppose that at the first
H2S gases.
stage, the water molecules from the humid
(5) This phenomenon is reversible, i.e., for air in the presence of the Au catalyst
Au/PS structures, inserting and remo‐ interact with the CO, resulting in the
ving the structure from the gas is formation of hydrogen, according to the
accompanied by the response and electrode reaction [25]
recovery of Voc, respectively.
CO + H2O → CO2 + H2 (9)
Thus, the above results, i.e., the voltage
H2 → 2H+ + 2e‐. (10)
generation in the Au/PS/Si Schottky‐type
structures in a humid, CO, or H2S atmos‐ After the reaction described by eq. (9), the
phere indicate, both the gas sensor and fuel formation of electricity proceeds in
cell functionalities of these structures. The accordance with eq. (10). Note that in spite
similar effect of the voltage generation was of the absence of hydrogen in the CO gas,
discovered upon dipping the Au(Ag,Cu)/ this gas is, nevertheless, hydrogen‐
PS/Si structures into different hydrogen‐ producing, as shown by eqs. (9) and (10).
containing solutions (KOH (potassium In the case of Au/PS/Si cell at H2S gas + air
hydroxide), CH3CH2OH (ethanol), CH3OH atmosphere the following reactions take
(methanol), C6H12O6 (glucose), H3BO3 (boric place in the presence of Au catalyst [22]
acid), C5H12 – C16H34 (benzine), NaBH4
(sodium borohydride), Black sea‐water etc) At the anode:
[13]. H2S + 2H2O → SO2 +6H+ + 6e‐ (11)
The mechanism of the generation of the At the cathode:
electricity in the metal/PS/Si cells under 6H+ + 6e‐ +3/2O2 → 3H2O (12)
humid conditions has already been
To overall, the voltage generation mecha‐
proposed [8, 12, 13]. We suggest that in
nism in Au/PS/Si structure at H2S atmos‐
Au/PS/Si cell, similar to Proton Exchange
phere is similar with the above‐described
Membrane (PEM) fuel cell [3], the Au film
mechanism for humid and CO ambient.
and PS layer play the role of the catalytic
anode and electrolyte, respectively. The The Ag/PS structure discovered humidity‐
interface region between the porous and sensitive properties due to change of the
crystalline silicon (PS/Si), which is very capacitance under water vapor exposition.
imperfect and stressed, plays the role of the Fig. 13 shows the humidity‐sensitive
cathode. Electrons and protons formed in properties of Au/PS sensor [19].The strong
Au catalyst film after hydrogen splitting dependence the capacitance on relative
(H2 → 2H+ + 2e‐), pass through the external humidity was observed because of the
circuit and along the pore surfaces of PS dielectric constant of pure water (about 80),
layer (electrolyte), respectively and reach that condensed on pores, is significantly
Number 25, 27
Tayyar Dzhafarov, Sureyya Aydın Yuksel
28 Journal of Qafqaz University
Nano‐Porous Silicon for Gas Sensor and Fuel Cell Applications
Hydrogen or a fuel like methanol applications for PEM cells are stationary
containing hydrogen is fed into the anode, power stations, engines of automobiles,
where the hydrogen atoms, encouraged by power sources for portable electronics etc.
a catalyst, split into protons and electrons
Table 1. Types of fuel cells
according to oxidation reaction
_______________________________________________
H2 →2H+ + 2e‐ (15) Fuel Cell types Fuel Efficiency Operating
(%) temp. (oC)
The protons pass through a selective _______________________________________________
electrolyte membrane, while the electrons
PEM H2 40‐50 ~80
are shunted off to another path, creating a
Direct Methanol Methanol 35 ~80
usable electric current. The protons and
(DMFC) Ethanol
electrons rejoin at the cathode, where the
Solid Oxide H2, CO, 45‐55
hydrogen reacts with oxygen from the air
(SOFC) CH4
to form water. Oxygen reduction reaction
Molten Carbonate H2, CO, 50‐60
on the cathode can be described as
(MCFC) CH4
2H+ + 2e‐ + 1/2O2 → H2O (16) Phosphoric Acid H2 40‐50
Fuel cells run on pure hydrogen gas, which (PAFC)
Number 25, 29
Tayyar Dzhafarov, Sureyya Aydın Yuksel
products and abundant natural resources. structure is very sensitive to NaBH4
However, the application of hydrogen for concentration. The Au/PS/Si structure on
power sources has been greatly restrained dipping into NaBH4 solution also exhibited
due to the lack of safe and convenient the short‐circuit current (about of
generation and storage methods. Hydrogen mA/cm2). pH measuring of NaBH4 solution
can be stored in high pressure tanks or showed that with increase of concentration
liquefied H2, or by adsorption on activated of NaBH4 from 10 to 30 mg/ml, pH of the
carbon, carbon nanotubes or in hydrogen‐ solution increases from to , i.e.
storing alloy [26]. Among hydrogen‐storing increase of pH of NaBH4 solution results in
materials, sodium borohydride (NaBH4) increase of voltage generated in the cell
due to the high hydrogen content (about of (Fig. 15). It should be noted that, as opposed
10% wt or kg/m3) is suggested as new to Au/PS/Si structure, in PS/Si structure
fuel media supplying hydrogen at normal (without the Au film) the marked gene‐
temperatures. The catalyc hydrolysis of ration of electricity on dipping its in NaBH4
sodium borohydride proceeds as solution was not observed.
NaBH4 + 2H2O → NaBO2 + 4H2 (20) The Voc‐N dependence observed in Fig. 15
can be explained by two concurrent pheno‐
As result of this reaction, each mole NaBH4 mena. The increase of NaBH4 concentra‐
can generate 4 moles of hydrogen gas. This tion, for the relative low contents of NaBH4
is a very effective system, since we are (N<30 mg/ml), is accompanied by increasing
getting hydrogen out of the water as well. of proton concentration (up to 2x cm‐3)
We get eight hydrogen atoms (four mole‐ and this results in rising of voltage. On the
cules) from just four atoms of hydrogen in other hand, at large contents of NaBH4
the NaBH The hydrogen is formed right (N>30 mg/ml), products of reaction (17)
there on the anode, and is thus precipitate in pores of Au and porous
immediately used by the fuel cells. NaBH4 silicon and thereby hindering penetration
is a nonreversible chemical hydride for the
of protons to interface. Thus, Schottky‐type
one‐time hydrolysis generation of H2. It is
Au/PS/Si structures sunk in NaBH4 and
shown that NaBO2 byproduct of reaction
other hydrogen‐containing solutions gene‐
(12) can be recycle back to NaBH4 using
rate a voltage up to mV. These data
coke or membrane [27]
indicate on perspectivity of using Au/PS/Si
The effect, similar to humidity‐voltaic effect structures as hydrogen cells.
[8 ], i.e. the generation a voltage between
Fig. 16 shows the open‐circuit voltage ge‐
the contacts to Au film and Si under
neration for the Au/PS/Si cell in H2S+dH2O
humidity exposition, was also discovered
solution at different concentration of H2S.
on dipping of Au/PS/Si structure into
Almost linear increase of voltage (from
NaBH4 solution. Fig. 15 illustrates the
open‐circuit voltage arising in Au/PS/PS to mV) is observed with increasing the
structure dependent on the concentration H2S concentration from 17 to 75 mM. Value
of NaBH4 solution (N) [16,17]. It is seen of Voc in pure water ( mV) is markedly
that the Voc – N dependence seems to be a lower than that in hydrogen sulphide‐
curve with a maximum (Voc = mV) at N containing solution [18]. Fig. 17 shows the
= 30 mg/ml. In the range of concentration of current‐voltage‐power output of Au/PS/Si
NaBH4 solution up to 30 mg/ml gradient of cell in H2S+dH2O solution. Results were
curve (dVoc/dN) is large (about 13 seafoodplus.info gained at room temperature with M
mg), i.e. voltage generated in Au/PS/Si hydrogen sulphide. From the polarization
30 Journal of Qafqaz University
Nano‐Porous Silicon for Gas Sensor and Fuel Cell Applications