bluuebunny/crossref_metadata_2025 huggingface dataset:
Kreativitas Guru dalam Pembelajaran di Kelas: Analisis Bibliometrik Dua Dekade Terakhir
Authors: Simangunsong Marta Florentina , Waspada Ikaputera , Rasto Rasto , Muhammad Ilham
Published: March 2024

Kreativitas guru memainkan peran penting dalam memberikan inspirasi dan mengembangkan kreativitas peserta didik dalam pembelajaran di kelas. Penelitian yang terkait dengan tema ini telah banyak dilakukan. Oleh karena itu diperlukan analisis terhadap hasil penelitian tersebut. Tujuan dari penelitian ini adalah untuk mengetahui tren publikasi terkait kreativitas guru pada pembelajaran di kelas dalam dua dekade terakhir. Database yang digunakan adalah Scopus.  Metode yang digunakan adalah analisis bibliometrik deskriptif. Tahapan penelitian meliputi identifikasi, penyaringan, penilaian kelayakan, dan inklusi, yang menghasilkan data akhir sebanyak 120 publikasi. Hasil penelitian menunjukkan bahwa jumlah publikasi terkait kreativitas guru mengalami peningkatan dalam beberapa tahun terakhir. Publikasi pada tahun 2018 juga menjadi yang paling berpengaruh terhadap penelitian ini, karena memiliki nilai h-index yang tinggi dari tahun lainnya. Negara Indonesia dan Amerika Serikat memiliki pengaruh yang signifikan dalam penelitian di bidang ini dibandingkan dengan negara lainnya. Penelitian-penelitian tersebut terfokus pada tiga area utama, yaitu: 1) kreativitas guru, pendidikan tinggi, dan motivasi; 2) kreativitas, sikap kreatif, dan berpikir kritis; serta 3) pendidikan, teknologi, dan inovasi. Tema-tema baru yang muncul dalam penelitian ini meliputi pendidikan tinggi, calon guru, teknologi, dan kurikulum. Temuan-temuan ini dapat memberikan kontribusi penting bagi pengembangan kreativitas guru dan peningkatan kualitas pembelajaran di masa depan.
Peningkatan Aktivitas Belajar IPA Siswa Kelas VII 2 SMP Negeri 2 Batang Anai dengan Menerapkan Strategi Pembelajaran Aktif Tipe GQGA
Authors: Syahrial Syahrial , Lefita Lefita , Erlinda Nelfi
Published: March 2024

This research is background by the low of student activity in learning IPA for VII.2 class student of SMPN 2 Batang Anai. The causes are the teacher still lack of using interesting learning strategies. The lack of student desire to repeat the lesson has been given at the school, so it is difficult to understand by the student. Consequently the result of student learning is low. One of the way in improving the student active learning is to implement active learning strategies through the type of Giving Question and Getting Answer (GQGA). The purpose of this research is to improve the student activity in learning IPA for VII.2 class students of SMPN 2 Batang Anai through the type of GQGA.The kind of the research is action class research. The subject of this research is VII.2 class students of SMPN 2 Batang Anai who registered in period of 2015/2016. The instrument of this research  was observation sheet in each meeting into two cyclus for student activity learning data, and result of final test in each final cyclus for result student learning data. Data analysis is like quantity analysis by using observation sheet, consist of positive and negative  activities indicator student as long as learning in the class.

Based on the data analysis is gotten the improve of student activities learning in positive indicator from 68% to cyclus 1 become 90% to cyclus 2. It influence to improve the student test achievement in percent in each final cyclus from 59% to cyclus 1 become 100% to cyclus 2. It can concluded there is improvement of the student activity in learning IPA for VII.2 class student of SMPN 2 Batang Anai through strategy active learning by the type of GQGA.
Kemampuan Kognitif Sains Siswa pada Pembelajaran Tatap Muka Terbatas Saat Pandemi Covid-19 di SDN Bandarhajo 02 Kota Semarang
Authors: Sulistyani Puteri Ramadhani  , Wartini Yulianti
Published: March 2024

Penelitian ini bertujuan untuk mengungkapkan sejauh mana pembelajaran yang dilakukan secara tatap muka terbatas terhadap kemampuan kognitif. Pandemi yang terjadi di indonesia berdampak pada dunia pendidikan yang mengharuskan semua kegiatan dilakukan secara daring di rumah. Seiring berjalan nya waktu pandemi di indonesia sudah mulai menurun sehingga pemerintah menetapkan pendidikan dilakukan kembali secara tatap muka terbatas yang dilakukan secara online 50% dan offline 50%. Penelitian ini menggunakan penelitian kualitatif dimana  dalam mengumpulkan informasi data peneliti melakukan wawancara terlebih dahulu , dan selanjutnya melakukan observasi secara langsung baik daring dan tatap muka serta mendokumentasikan setiap berlangsung nya kegiatan pembelajaran. Hasil dalam penelitian, menunjukkan bahwa dampak pada pembelajaran tatap muka terbatas terhadap kemampuan kognitif anak secara langsung mengalami hambatan. Dikarenkan pembelajaran yang  dilakukan secara bersamaan baik itu daring maupun tatap muka langsung di sekolah membuat guru hanya fokus mengoprasikan media pembelajaran berupa power point. Sehingga tidak ada nya contoh kongkret.
On definitions and guiding principles in ethnomusicological minority research
Authors: Hemetek Ursula , Kölbl Marko
Published: March 2024

The foundation of the MMRC in November 2019 as the first Music and Minorities Research Center worldwide raised a lot of questions concerning theories and methods in ethnomusicological minority research. At the core of the lively discussions among the international advisory board of the MMRC were definitions as well as guiding principles. While the varying definitions of the term “minority” are a theoretical issue, the guiding principles of research are very much connected to methods. Adelaida Reyes was a key figure in these discussions but also in earlier ones that happened at the time of the foundation of the ICTM Study Group on music and minorities. Drawing from her work this article deals in its first part with the term “minority”, the historical perspectives of its use and meanings. The second part is concerned with methodological issues with a special focus on future perspectives, that include dehierarchisation as well as decolonisation of ethnomusicology. The article pays tribute to the foundational work of Adelaida Reyes and many of her peers in the early development of ethnomusicological minority research, which helps scholars of today to pay attention to power relations as well as intersectional approaches in ethnomusicological minority research. Thus minority research proves to have the potential to influence the discipline ethnomusicology in general.
Musical communities of sexual minorities
Authors: Kopaniecki Jakub
Published: March 2024

Wroclaw, one of the largest cities in Poland, is full of events taking place in public space, including protests. Using examples taken from the 10th Wroclaw Equality March in 2018, it can be shown that specific musical works become a weapon in the struggle for recognition of the proclaimed values. The study traces the auditory dimension of protests, the role of music in creating a community and the place of such events in the soundscape of a contemporary city. Then the study presents these mechanisms on selected musical examples. Particular attention is paid to the musical communities, because the sound not only accompanies the protests it strengthens the sense of solidarity between the participants. The event is interpreted as a kind of spectacle that constitutes a space for self-expression and the articulation of the postulates of its participants, accompanied by a characteristic soundtrack. It consists mainly of popular music performed by artists either belonging to sexual minorities or being recognized as icons of the community. The study presents the role of disco music and club culture as well as the aesthetics of the camp as crucial for LGBT+ people seeking space for their expression, which is oppositional to the dominant system of values based on gender dualism. Seemingly simple or silly songs can have a deeper meaning and are a key element in shaping a certain community.
Dos lamentos a través de tres interjecciones en un pasaje de Los Acarnienses de Aristófanes
Authors: Bayo Gisbert Óscar
Published: March 2024

En la primera de las comedias conservadas de Aristófanes, Los Acarnienses, encontramos un pasaje (Ar. Ach. 1078-1084) de especial interés en cuanto a la expresión de lamento. Lámaco, general belicoso hasta el tuétano, se lamenta porque ha recibido la noticia de que debe marchar al ejército. Diceópolis, por su parte, comienza a burlarse de él lamentándose de manera fingida. Qué significa cada interjección —si es que significan algo por sí mismas—, cómo se insertan dentro de los enunciados y qué condiciones deben cumplir para que la expresión de la emoción sea exitosa son las cuestiones que trata de responder este estudio.
o thrinos yia ton Diyeni Akriti kai tous oikeious tous sto omonimo bizantino epos. Mia proti sinkritiki prosengisi me ton thrino yia ton Ektora stin Iliada
Authors: Kioridis Ioannis , Charakopoulos Christos
Published: March 2024

The motif of epic lamentation for familiar persons who have passed away has been a popular theme in world literature since the Epic of Gilgamesh and Homer’s Iliad. In this contribution, we focus on the Byzantine epic poem of Digenes Akrites, written by an unknown author of the early 12th century, which recounts the exploits of the eponymous hero on the frontier between the Byzantines and the Arabs. Six manuscripts in Greek survive today (apart from some adaptations in Old Russian), which are variants of the lost original version—all date from the mid-13th or 14th century to the 17th century. Our interest focuses on the four laments for Akritis’ father and mother, himself and his wife, as presented in the six manuscripts. The approach will be comparative between the six texts, the laments for Digenes and similar laments for Hector in the Iliad. Finally, it is essential to draw on Zumthor’s schema of epic lament in French epic medieval texts, and the form in which it is found in the epic laments we are studying.
Linos et linos. La lamentation dans la littérature grecque ancienne à travers la Périégèse de Pausanias
Authors: Stratiki Kerasia
Published: March 2024

Homère est le premier à nous informer que les Grecs chantaient une complainte sur le malheur de Linos et qu’Héphaïstos avait représenté sur le bouclier d’Achille un enfant portant la lyre qui chantait pour Linos. Ensuite, Pamphos, se référant à la lamentation des hommes sur sa mort, l’avait appelé Oitolinos. De même, Sappho, qui connaissait l’oeuvre épique de Pamphos, a chanté Adonis avec Oitolinos en associant ce dernier à Linos du fait de leurs malheurs communs, tous deux tués par un dieu et morts prématurement. Hérodote, donnant davantage d’information, écrit qu’en dehors de la Grèce, le chant funèbre linos était connu dans nombreux pays d’Orient sous un nom chaque fois différent. De toute évidence, soit comme linos soit comme maneros ou bormos, c’était un chant funèbre qui était associé à la mort prématurée d’un jeune home. Ainsi, dans la Périégèse de Pausanias, le héros pastoral Linos recevait un culte local, puisqu’il était honoré seulement à Argos, alors que le héros civilisateur Linos faisait l’objet d’un culte plus vaste, bien que le culte principal fût céléblré sur l’Hélicon, le mont sacré des Muses, les déesses protectrices de l’art lyrique, qui furent les premières à pleurer sa mort tragique. Comme son titre l'indique, cette étude est centrée sur la Périégèse de Pausanias, car elle présente les cultes les plus répandus dans les lieux de la Grèce antique et notamment par l'ensemble des informations concernant certaines régions particulières. En tant que tel, il est une riche source du mythe et du culte de Linos à Hélicon et à Argos.
Behavior change intervention to sustain iodide salt utilization in households in Ethiopia and study of the effect of iodine status on the growth of young children: community trial
Authors: Ferede Abebe , Abera Wordofa Muluemebet , Belachew Tefera
Published: March 2024

Background

Monitoring systems in a broad range of countries are a notable effort to eliminate iodine deficiency disorders (IDDs). This study aimed to gather data on the amount of iodide present in table salt and how household consumption patterns affect children’s iodine status and its effect on their growth.

Methods

A single treatment arm community trial study design was designed. Lower community units (LCUs) were chosen at random from districts assigned either intervention or control. From a list of LCUs, 834 mothers and their paired children were chosen randomly. Urine and table salt samples were collected and examined in the national food and nutrition laboratory. The deference between arms was determined using a t test, and the generalized estimating equation (GEE) was used to forecast parameters.

Results

The mean iodide content in the table salt samples of 164 (98.1%) was 45.3 ppm and a standard deviation (SD) of 14.87, which were above or equal to the recommended parts per million (ppm). Between the baseline survey and the end-line survey, the mean urine iodine concentration (UIC) was 107.7 µg/L (+/− 8.64 SD) and 260.9 µg/L (+/− 149 SD). Children’s urine iodine excretion (UIE) had inadequate iodine in 127 (15.2%) children at the beginning of the study, but only 11 (2.6%) of the intervention group still had inadequate iodine at the end. The childrens’ mean height (Ht) was 83.1 cm (+/−10 SD) at baseline and 136.4 cm (+/−14 SD) at the end of the survey. Mothers knew a lot (72%) about adding iodized salt to food at the end of cooking, and 183 (21.9%) of them did so regularly and purposefully. A total of 40.5% of children in the intervention group had stunted growth at baseline, which decreased to 15.1% at the end of the study but increased in the control group to 51.1%. The mean difference (MD) of urine iodine concentration (UIC) between intervention and control groups was 97.56 µg/L, with a standard error (SE) of 9.83 (p = 0.001). The end-line Ht of children in the intervention group was increased by 7.93 cm (β = 7.93, p = 0.005) compared to the control group.

Conclusions

Our research has shown that mothers who embraced healthy eating habits had perceived improvements in both the iodine status and height growth of their children. In addition to managing and using iodine salt, it has also introduced options for other healthy eating habits that will also play a significant role in their children’s future development. This sort of knowledge transfer intervention is essential for the sustainability of society’s health. Therefore, this trial’s implications revealed that the intervention group’s iodine status and growth could essentially be improved while the control group continued to experience negative effects.

Trial registration

ClinicalTrials.gov Identifier: NCT048460 1.
Validation of the questionnaire “Pregnancy Vaccine Hesitancy Scale (pVHS)” toward COVID-19 vaccine for Malaysian pregnant women
Authors: Che Mood Nur Azreen , Mat Yudin Zainab , Ahmad Wan Muhamad Amir W , Abdul Kadir Azidah , Norhayati Mohd Noor , Md Nawawi Noorfaizahtul Hanim , Mohamad Zon Erinna , Ali Norsiah
Published: March 2024

Background

Pregnancy is one of the risks for severe COVID-19 infection, and receiving a vaccination is one of the effective methods to reduce disease severity. However, COVID-19 vaccine hesitancy among pregnant women remains an issue. This study aims to develop and validate the pregnancy Vaccine Hesitancy Scale (pVHS) toward COVID-19 vaccine for Malaysian pregnant women.

Method

An 8-item Malay language pregnancy Vaccine Hesitancy Scale (pVHS-M) for COVID-19 was adapted from the adult Vaccine Hesitancy Scale and validated using Exploratory Factor Analysis. Six expert panels were involved in content validity, and ten pregnant women were involved in face validity. A cross-sectional study on 200 pregnant women was conducted between October 2022 and March 2023 at the Obstetrics and Gynaecology Clinic, Universiti Sains Malaysia, Kelantan.

Result

The item-level content validity index is 1.00, demonstrating good relevance of the eight items used to assess COVID-19 vaccine hesitancy. The item-level face validity index obtained is 0.99, indicating that the items were clear and comprehensible. The Cronbach alpha score was 0.944, with factor loadings ranging from 0.79 to 0.89.

Conclusion

The pVHS-M demonstrated good internal consistency, indicating that it is a valid and reliable tool for assessing COVID-19 vaccine hesitancy among pregnant women.
Robust stability of a continuous‐time self‐tuning controller
Authors: Gawthrop P. J.
Published: July 2007

A continuous‐time self‐tuning controller, based on the well‐known discrete‐time generalized minimum‐variance self‐tuning controller, is introduced. Using input—output stability methods, frequency domain conditions are derived which ensure L∞ stability in the face of multiplicative process perturbations. The analysis is illustrated using an example of Rohrs et al.
Novel electrically conductive and ferromagnetic composites of poly(aniline‐co‐aminonaphthalenesulfonic acid) with iron oxide nanoparticles: Synthesis and characterization
Authors: Reddy Kakarla Raghava , Lee Kwang‐Pill , Gopalan Anantha Iyengar
Published: July 2007

Nanocomposites of iron oxide (Fe3O4) with a sulfonated polyaniline, poly(aniline‐co‐aminonaphthalenesulfonic acid) [SPAN(ANSA)], were synthesized through chemical oxidative copolymerization of aniline and 5‐amino‐2‐naphthalenesulfonic acid/1‐amino‐5‐naphthalenesulfonic acid in the presence of Fe3O4 nanoparticles. The nanocomposites [Fe3O4/SPAN(ANSA)‐NCs] were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, elemental analysis, UV–visible spectroscopy, thermogravimetric analysis (TGA), superconductor quantum interference device (SQUID), and electrical conductivity measurements. The TEM images reveal that nanocrystalline Fe3O4 particles were homogeneously incorporated within the polymer matrix with the sizes in the range of 10–15 nm. XRD pattern reveals that pure Fe3O4 particles are having spinel structure, and nanocomposites are more crystalline in comparison to pristine polymers. Differential thermogravimetric (DTG) curves obtained through TGA informs that polymer chains in the composites have better thermal stability than that of the pristine copolymers. FTIR spectra provide information on the structure of the composites. The conductivity of the nanocomposites (∼ 0.5 S cm−1) is higher than that of pristine PANI (∼ 10−3 S cm−1). The charge transport behavior of the composites is explained through temperature difference of conductivity. The temperature dependence of conductivity fits with the quasi‐1D variable range hopping (quasi‐1D VRH) model. SQUID analysis reveals that the composites show ferromagnetic behavior at room temperature. The maximum saturation magnetization of the composite is 9.7 emu g−1. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Die mechanische Aktivierung von Quarz
Authors: Schrader Richard , Dusdorf Wolfgang
Published: July 2007

Quarz wurde in einer Schwingmühle bei verschiedenen Zeiten trocken gemahlen. Röntgenographische, ultrarotspektroskopische, differentialthermoanalytische Untersuchungen und Dichtemessungen zeigen, daß langzeitig gemahlener Quarz in einen amorphen Zustand übergeht. Die Amorphisierung wird durch fortschreitende Ausbildung von Gitterstörungen erreicht. Die einzelnen Mahlchargen enthalten je nach Mahldauer verschiedene Mengen kristallines und amorphes Material. Der amorphe Anteil zeigt erhöhte Bereitschaft zur Cristobalitbildung und zum Auflösen in Natriumhydroxyd und Salzsäure.
Zur Kristallchemie intermetallischer Verbindungen
Authors: Schulze G. E. R.
Published: July 2007

Nach einer kurzen Kennzeichnung der Sonderstellung der intermetallischen Verbindungen wird auf einige thermodynamische Gesichtspunkte bei ihrer Behandlung hingewiesen und die Methode der Strukturargumente in diese allgemeinen Zusammenhänge eingeordnet. Die Strukturargumente der Koordinationszahl und der größten Dichte werden näher besprochen. Namentlich letzteres wird am Beispiel der Laves‐Phasen eingehend erörtert und seine allgemeine Bedeutung im Gebiet intermetallischer Verbindungen dargelegt.
Effektive Ionenladungen von AIIIBV‐Verbindungen
Authors: Sirota N. N. , Gololobov E. M. , Olechnovič N. M. , Šeleg A. U.
Published: July 2007

In der vorliegenden Arbeit werden einige Resultate diskutiert, die durch röntgenographische Bestimmung der effektiven Ionenladungen von AIIIBV‐Verbindungen aus Diagrammen der Elektronendichte ϱ(x, y, z), den Strukturamplituden und den Atomformfaktoren von Ionen erhalten wurden. Die auf diese Weise ermittelten Werte werden mit röntgenspektroskopischen Daten verglichen.
Über die Polymorphie der Indiumphthalocyanine
Authors: Mühl P.
Published: July 2007

Die IR‐Absorptionsspektren konnten zum Nachweis der Existenz und zur Unterscheidung der beiden Modifikationen beim Chlorindiumphthalocyanin herangezogen werden. Die α‐Form des Chlorindiumphthalocyanins geht durch thermische Behandlung oder durch Kernreaktorbestrahlung in die β‐Form über. Die Unterschiede in den Spektren werden empirisch interpretiert.

Chlorindiumchlorphthalocyanin liegt in α‐Modifikation vor. Es ist weder thermisch noch durch Reaktorbestrahlung in die β‐Form überführbar. Da diese Verbindung außerdem nicht unzersetzt sublimierbar ist, kann angenommen werden, daß sich das Chlor in 4‐Stellung am Benzolkern befindet.
Some applications of the Taylor theory of polycrystal plasticity
Authors: Bunge H. J.
Published: July 2007

The Taylor theory of polycrystal plasticity was applied to three‐axial deformation accomplished by glide on (111) [110] or (110) [111] glide systems. The orientation dependence of the Taylor factor was used to calculate the angular dependence of the relative strength of a textured material. The angular dependence of the strain ratio R — calculated from the minimum value of the Taylor factor — was compared with the measured strain ratio. The orientation changes of the crystallites of a polycrystalline aggregate after 1% plastic deformation were calculated and compared with experimental values. The orientations which are deformed without orientation changes were calculated and compared with those of maximum orientation density found by a three‐dimensional texture analysis of cold rolled copper and iron. The dependence of the rotationless orientations on the axis ratio of the deformation tensor was calculated. This allows suggestions to be made on the dependence of the rolling textures on the lateral broadening of the sheet during rolling.
Zur Kinetik des Kondensationsvorganges
Authors: Zinsmeister G.
Published: July 2007

Im Gegensatz zu den üblichen Darstellungen der Keimbildungstheorie wird nicht die Thermodynamik, sondern die Kinetik in den Vordergrund gestellt. Es werden die grundlegenden Gleichungen der Kondensationskinetik für diskrete und kontinuierliche Variable angegeben und die bekannten Arbeiten von FARKAS, BECKER‐DÖRING und FRENKEL‐ZELDOVITCH von einem einheitlichen Gesichtspunkt aus diskutiert. Ferner wird der Spezialfall der Kondensation dünner Schichten behandelt.
Zur Kristallographie von Doppelsalzen aus Calciumsulfat und Natriumsulfat
Authors: Emons H.‐H. , Seyfarth H.‐H. , Stegmann E.
Published: July 2007

In the course of investigating a special slurry problem in the Na2SO4 production metastable double salts of calcium sulphate and sodium sulphate were detected (Emons, Stegmann). In this paper it is reported on the properties of these compounds and their decomposition products, determined by microscopic, X‐ray, thermoanalytic, and IR‐spectroscopic methods.
Schichtzusammensetzung und Temperaturkoeffizient aufgedampfter Nickel/Chrom‐Schichten
Authors: Schippel E.
Published: July 2007

Bei 300°C durch Sublimation auf keramischen Substraten aufgedampfte Ni/Cr‐Schichten von 100, 500 und 800 Ω/□ zeigen eine stetige Änderung des TK mit der Schichtzusammensetzung, wobei als Extremwerte im negativen und positiven Bereich der TK von Chrom‐ bzw. Nickel‐Schichten gemessen wurde. Der TK Null wird hier für eine Schichtzusammensetzung von 55 bis 60% Chrom erhalten.

Bei 100°C aufgedampfte Ni/Cr‐Schichten weisen eine TK‐Anomalie bei einer Schichtzusammensetzung um 50% Chrom auf, die strukturbedingt sein muß.

Die beste Stabilität wurde für Schichten mit ca. 40% Chrom erreicht und steigt mit der Substrattemperatur.
Crystal chemical stability conditions for intermetallic compounds (I) frequency distributions of laves‐phases
Authors: Leitner G. , Schulze G. E. R.
Published: July 2007

Based on a card index of intermetallic compounds the frequency of representatives for important structure types is described and their possible simultaneous occurrence within a binary system investigated. Considering the radius ratio, valence electron concentration and structure type the stability conditions for the individual cases of Laves‐phases are given besides those considerations typical for the whole group. From analogy for related systems Laves‐phases hitherto unknown are predicted. The effect of electron concentration and radius ratio on the structure of Laves‐phases is discussed.
The change of the lattice constant in heteroepitaxial silver films with increase of thickness
Authors: Sheftal R. N.
Published: July 2007

Deposition of silver on NaCl, KCl, and LiF with 20 Å · s−1 in vacuum (5 · 10−6 torr) and electronographical determination of changes of lattice constant. Precision of measurement better than ± 0.004 Å (reflections {400} and {220}). Thickness of films from 50 to 500 Å with intervals of 10 Å. The lattice parameter of films till to 115 Å in thickness did'nt differ from the parameter of bulk silver (4.086 Å). At about 175 Å the parameter reached minimum (about 4.00 Å) and took again the parameter of bulk material with the film thickness of 215 Å. With polycrystals no changes of lattice parameters occurred. – The phenomenon is connected to growth mechanism, two‐dimensional and three‐dimensional nucleation and to the differences in lattice parameters of substrate and deposit.
Transport and Deposition of SiO2 with H2O under Supercritical Conditions
Authors: Flörke O. W.
Published: July 2007

Transport and deposition of silica in different forms: quartz, chalcedony, cristobalite, tridymite and hyalite were investigated between 400‐800°C and 200 to 2000 bar. The conditions of formation of the forms are discussed. The crystallization of quartz whiskers is reported and ideas of the formation of hyalite are given. Conclusions are drawn to natural occurences.
Silicon‐Free Compounds with Sodalite Structure
Authors: Saalfeld H. , Depmeier W.
Published: July 2007

Mit Hilfe von Sinterreaktionen wurden sieben chemisch unterschiedliche Verbindungen mit Sodalithstruktur hergestellt. Für Ca4Al6O12 · SO4 sind Vorschläge über die Atomanordnung in einer Subzelle (a = 9,20 Å) mit der Symmetrie I 43 m sowie in der echten Zelle (a = 18,41 Å) mit der Symmetrie I 4132 gemacht worden.
Aluminiumoxid für technische Anwendungen
Authors: Žemlička J. , Barta Č.
Published: July 2007

Es wird eine Methode zur Herstellung von Aluminiumhydroxid, α‐ und γ‐Al2O3 hoher Reinheit und geeigneten physikalischen Eigenschaften beschrieben. Die γ‐Modifikation von Al2O3 wurde als Ausgangspulver für die Herstellung von Korundkristallen erprobt und die α‐Modifikation als wirksames Poliermittel für Kristalle getestet. Wegen der physikalischen Eigenschaften und sphärischen Form der Teilchen erscheint dieses Aluminiumoxid künftig auch für andere technische Anwendungen geeignet.
Untersuchung von Heterostrukturen der Mischkristallreihe GaAs/AlAs mit dem Rasterelektronenmikroskop
Authors: Johansen H. , Herrmann F. P.
Published: July 2007

Die Untersuchung von Heterostrukturen der Mischkristallreihe GaAs/AlAs mit Hilfe verschiedener rasterelektronenmikroskopischer Techniken führt zu dem Ergebnis, daß zum Nachweis von geringen Bandabstandsänderungen die Ausnutzung der Katodolumineszenz sehr geeignet ist. Der Vorteil, der sich gegenüber dem Sekundärelektronenkontrast bzw. der Abbildung mit rückgestreuten Elektronen hinsichtlich einer materialspezifischen Identifizierung ergibt, ist eindeutig. Der Verlauf des Intensitätsprofils bei steigender Primärelektronenenergie erlaubt den Nachweis eines qualitativen Zusammenhanges zum Wert des Bandabstandes. Dies wird an zwei Heterostrukturen mit stark unterschiedlicher Dotierung demonstriert. Mit Hilfe der Y‐Modulationstechnik gelingt es, einen orientierungsabhängigen Anteil im Bildkontrast bei Homo‐ und Heteroübergängen von Mehrfachstrukturen nachzuweisen.
Einfluß der Temperung auf die optische Homogenität von Korund‐Einkristallen
Authors: Kvapil Jiŕí , Sùlovský Juraj , Kvapil Josef
Published: July 2007

Der Einfluß der Temperung von Korund‐Einkristallen wurde anhand der Erniedrigung der Zahl der Interferenzlinien untersucht. Die Temperung bei einer Temperatur von mindestens 1100‐1200°C verbessert die optische Homogenität der perfekten Kristalle. Weitere Temperung bei einer Temperatur von 1900‐1980°C hat nur eine geringe Erhöhung der optischen Homogenität der Rubin‐Einkristalle zur Folge.
Nonlinear Optical Properties of Isomorphic Family of Crystals with Yttrium‐Aluminium Borate (YAB) Structure
Authors: Filimonov A. A. , Leonyuk N. I. , Meissner L. B. , Timchenko T. I. , Rez I. S.
Published: July 2007

The second harmonics generation of Nd‐laser radiation (λ = 1.06 microns) of the isomorphic family of crystals with yttrium‐aluminium borate (YAB) structure — RAl3(BO3)4 (R = Y, Sm, Eu, Gd, Dy, Er, Ho, Tu) — investigated using the powder method and the theoretical calculation of SHG–coefficients — are reported. The refraction indices (for λ = 5481 Å) and optical sign for all studied YAB‐type crystals are determined with the help of the immersion method. All studied crystals possess PM direction and oee‐interaction. The SH‐intensity is of KDP order of magnitude, with reasonable correlation of experimental and theoretical data. Theoretical analysis of the contributions of different ions to the integral d magnitude has shown identical signs for all ion species in YAB structure type.
The Precipitation of Alkaline‐Earth Metal Oxalate Powders from Aqueous Solution. Crystal Numbers and Final Sizes
Authors: Packter A. , Chauhan P.
Published: July 2007

The precipitation magnesium oxalate dihydrate, calcium oxalate monohydrate, strontium oxalate monohydrate and barium oxalate hemihydrate was studied from equivalent solutions of concentrations from 0.001 M to 0.5 M, at pHs from 7 to 6, by optical microscopy and other methods. Crystal growth started after induction periods: the precipitations were heterogeneously nucleated at low supersaturations and homogeneously nucleated at medium to high supersaturations. The crystal form and numbers of the final precipitates depended on the type and number of the nuclei (and crystallites) formed during the induction periods. Crystal numbers at medium to high supersaturation, increased with increasing initial mean metal oxalate concentrations according to the relation, N = N1c; β was 5 for calcium oxalate precipitations and β was 6 for the other metal oxalate precipitations. The N1 values increased in the order MgC2O4 · 2 H2O < BaC2O4 · 1/2 H2O < SrC2O4 · H2O < CaC2O4 · H2O.

The final crystal lengths, in this supersaturation range, then decreased (from maximum values) with increasing initial concentrations according to the relation, lfin = l1/CMOxβ, where γ was 1.3 to 1.6. For precipitations from solution of any concentration at any pH, smaller crystals were obtained in the precipitates of the metal oxalate of lower solubility.
Determination of Composition and Inhomogeneity in GaAs1−xPx Epitaxial Layers
Authors: Somogyi M. , Barna Á.
Published: July 2007

A method is given for the rapid determination of the composition and the carrier concentration in GaAs1−xPx epitaxial layers. The composition was determined from the photoresponse of the Schottky‐barriers. A calibration curve was constructed using the absolute composition data determined by microprobe analysis. The concentration values were obtained from the usual C‐V dependence.
Zu Fragen der Legierungsbildung bei Bimetallkatalysatoren
Authors: Engels S. , Wilde M.
Published: July 2007

Es werden Probleme der Legierungsbildung und Oberflächenzusammensetzung von Bimetallkatalysatoren sowie einige Untersuchungsergebnisse über die Legierungsbildung bei Ni–Cu‐η‐Al2O3‐Katalysatoren diskutiert.
Electron microscopic study of zinc oxide crystals microstructure crystallizing in a double hexagonal close‐packed lattice
Authors: Nowok J.
Published: July 2007

Transmission electron microscopy and electron diffraction have been used to investigate ZnO crystals microstructure and to study structural phase transformation. The results indicate that a one‐to‐one correspondence between lattice defects and phase transformation in ZnO crystals exist.
Broadening of X‐ray diffraction lines of crystals containing dislocation distributions
Authors: Wilkens M.
Published: July 2007

The first part of the paper deals with a brief review over the present stage of the (kinematical) theory of the broadening of X‐ray diffraction lines of crystals containing dislocation distributions. In the second part experiments of X‐ray line broadening of plastically deformed Cu and NaCl single crystals are reported by which the validity of the theoretical approaches are tested. It is shown that values of the dislocation density and the elastically stored energy derived from broadened X‐ray diffraction lines agree well with corresponding data obtained by other experimental techniques.
Zum Reflexionsvermögen und Polarisationsverhältnis bei der Röntgenstrahlbeugung am Realkristall (I) Experimentelle Ergebnisse und Vergleich mit der Theorie
Authors: Stephan D. , Löschau W.
Published: July 2007

Die experimentellen Ergebnisse und deren unbefriedigende theoretische Widerspiegelung sowie praktische Probleme (Einsatz von Kristallmonochromatoren, Realstrukturanalyse) machen eine Verbesserung der Theorie für das integrale Reflexionsvermögen Ri und das Polarisationsverhältnis p bei der Röntgenstrahlbeugung an dicken Realkristallen (symmetrischer Bragg‐Fall) notwendig. Über die Beschreibung des Beugungsvorganges in einem Schichtenmodell mit dynamisch beugenden Mosaikblöcken werden relativ einfache Ausdrücke gewonnen, die die experimentellen Ergebnisse — insbesondere das Maximum von p bei mittlerer Kristallgüte — wiedergeben. Die Theorie liefert für das Polarisationsverhältnis bei starker Primär‐ und Sekundärextinktion als Höchstwert p = \documentclass{article}\pagestyle{empty}\begin{document}$ \sqrt {|\cos 2\Theta |} $\end{document}, der für übliche Monochromatorkristalle nach den vorliegenden Meßwerten offensichtlich mit größerer Wahrscheinlichkeit gilt als p = cos2 2 Θ oder | cos 2 Θ| oder Mittelwerte davon.
Bestimmung der OH−‐Konzentration in LiNbO3‐Kristallen durch Protonenresonanz‐Untersuchungen
Authors: Bollmann W. , Schlothauer K. , Zogal O. J.
Published: July 2007

Mit Hilfe von Eichproben konnte durch Kernresonanz‐Untersuchungen die OH−‐Konzentration in LiNbO3‐Kristallen bestimmt und deren Beziehung zur 2,7 μm‐Absorptionsbande angegeben werden: N = (3 ± 1) · 1019 k (2,87 μm) cm−3. Dies erlaubt die quantitative Bestimmung der OH−‐Konzentration durch einfache optische Absorptionsmessungen.
Data on nucleation and growth of sodium trimolybdate crystals
Authors: Hodorowicz S.
Published: July 2007

The influence of acidification on crystallization and kinetics of growth of sodium trimolybdate has been interpreted. Furthermore the process of nucleation at the surface layer of the solution has been described.
Zur Thermodynamik des Systems Si–C–Cl–H und Darstellung von phasenreinem SiC
Authors: Selbmann D. , Wolf E. , Schönherr M. , Leonhardt A.
Published: July 2007

Es wird ein Weg zur thermodynamischen Berechnung der Darstellungsbedingungen binärer und komplizierterer Verbindungen durch Gasphasenabscheidung beschrieben, und damit werden die Abscheidungsbedingungen der reinen SiC‐Phase im System Si–C–Cl–H sowie die Koabscheidungsbedingungen mit den benachbarten Phasen ermittelt. Die experimentelle Überprüfung der relative großen berechneten Darstellungsbereiche ergab insbesondere oberhalb 1700 K eine gute Übereinstimmung.
Quantenmechanische Gesetzmäßigkeiten bei Kristallisationsprozessen an Phasengrenzflächen von Ionenkristallen (III)
Authors: Winzer A.
Published: July 2007

Die Aktivierungsenergien für die Phasengrenzflächenprozesse an AgCl‐ und AgBr‐Niederschlägen wurden mittels der Methode der markierten Atome gemessen und mit den auf quantenmechanischer Grundlage berechneten Werten verglichen. Dabei zeigte sich eine gute Übereinstimmung der gemessenen und berechneten Werte. Es werden quantenmechanische Gesetzmäßigkeiten bei Stoffübergangsprozessen and den Phasengrenzflächen von AgCl‐ bzw. AgBr‐Niederschlägen diskutiert. Es besteht zwischen der Aktivierungsenergie für den Stoffübergang bei Kristallisationsprozessen bzw. der Grenzflächenenergie und der Frequenz der longitudinalen optischen Phononen eine direkte Proportionalität, wobei die Proportionalitätskonstante die Plancksche Konstante h ist.
Growth and some properties of cerium sulphate enneahydrate single crystals
Authors: De Saja A. , Pastor J. M. , Rull F. , De Saja J. A.
Published: July 2007

Colorless single crystals of cerium sulphate enneahydrate were grown from aqueous solutions under carefully controlled conditions of temperature and supersaturation. Polarized Raman spectra and vibrational assignments of oriented single crystals are reported. Several physical properties (density, refractive indices, dielectric constants, coefficient of linear expansion, specific heat, microhardness) are also listed.
Einfluß der Temperatur auf die Versetzungsstruktur in der Umgebung von Mikrohärteeindrücken in Eiseneinkristallen
Authors: Brenner B.
Published: July 2007

Auf {100}‐Flächen von Reineiseneinkristallen wurde die Temperaturabhängigkeit der Mikrohärte im Temperaturbereich von 200 K bis 1180 K gemessen und die Versetzungsstruktur in der Umgebung der Mikrohärteeindrücke mittels TEM, Lichtmikroskopie und Ätztechnik untersucht. Es wurde festgestellt, daß die einzelnen Bereiche der Mikrohärte‐Temperatur‐Kurve mit charakteristischen Versetzungsanordnungen korrelieren. An Hand dieser Beobachtungen werden mögliche Verformungsprozesse diskutiert.
Investigations of crystal defects with reflection‐section topography
Authors: Zaumseil P.
Published: July 2007

A simple topographic technique is presented that allows an exact determination of the depth of kinematically reflecting regions below the crystal surface. A kinematical reflection full of contrast can be achieved by a spatial separation of the images from perfect and disturbed parts of the crystal. Possible applications of reflection‐section topography are e.g. demonstrated by lattice deformations caused by laser irradiation and ion implantation as well as by growth bands and dislocations. In weakly deformed crystals a new kind of interference fringes can be observed.
Absorption and electrical conductivity of CaMoO4 crystals
Authors: Bollmann W.
Published: July 2007

The electrical conductivity σ of CaMoO4 crystals was investigated between room temperature and 850°C. The mobility vv and the diffusion coefficient Dv of the O− ion vacancies have been derived from σ: vvT = 3300 exp (−1.52 eV/kT) cm2 K/Vs, Dv = (0.1…1) × exp (−1.52 eV/kT) cm2/s. An absorption occuring in crystals which are reduced or X‐irradiated at low temperatures is dichroitic and caused by Mo5+ ions. For measurement in c direction the oscillator strength of the 680 nm absorption band is found to be about 0.1.
Investigations on the crystallization of larger NaA and NaX zeolite crystals in the presence of triethanolamine (I). The influence of Na2O and SiO2 content
Authors: Neels H. , Schmitz W. , Berger E.‐M. , Lutz D.
Published: July 2007

Sodium silicate‐aluminate aqueous systems with various contents of Na2O and SiO2 containing triethanolamine were crystallized. Optimum Na2O and SiO2 contents have been observed to give NaA and NaX zeolite crystals with dimensions up to 80 μm. For NaA crystals the values are: ∼ 3.5 mass% Na2O, ∼ 1.65 mass% SiO2; for NaX crystals ∼ 2.5 mass% Na2O, ∼ 1.5 mass% SiO2. – The effect of other additives on crystal size is proved. – The results are discussed in terms of nucleation and growth, reaction rate, and supersaturation. Supposition are made to gain larger crystals by maintaining the excess of solute over a longer period of time.
Influence of tetrahedral aluminium on the hydrothermal transformation of montmorillonite and beidellite to mixed‐layer illite‐montmorillonite and illite
Authors: Frank‐Kamenetski V. A. , Kotelnikova E. N. , Kotov N. V. , Starke R.
Published: July 2007

In weathering crusts, sedimentary rocks and zones of hydrothermal transformation frequently mixed‐layer illite‐montmorillonite will occur. Based upon new experimental transformations of montmorillonite and beidellite under hydrothermal conditions in the presence of potassium chloride it is shown that mixed‐layer illite‐montmorillonite, with decreasing expandable proportion, occurs in the form of transitional stages of the montmorillonite → illite transformation. Besides the increase of reaction temperature or potassium concentration, it is first of all an increased charge of the (Si, Al)O4 tetrahedral layers of the dioctahedral smectites that contribute considerably to accelerating the formation of illite‐montmorillonite mixed‐layers, lowering their expandable proportion and converting these mixed layers to illite.
Thermodynamische Studien an AIII‐BV‐Verbindungen. Vergleich der thermodynamischen Konsistenz verschiedener Modellansätze für Aktivitätskoeffizenten
Authors: Peuschel G.‐P. , Apelt R. , Knobloch G. , Butter E.
Published: July 2007

Anhand vorhandener experimenteller Daten der Gleichgewichte fest‐flüssig und flüssig‐gasförmig des Systems InAs wurde überprüft, inwieweit die Modelle von BREBRICK und KRUPKOWSKI sowie die QCE‐Näherung diese widerspruchsfrei beschreiben können. Das KRUPKOWSKI‐ und das BREBRICK‐Modell sind als thermodynamisch konsistent einzuschätzen. Aufgrund des einfacheren Ansatzes sollte das KRUPKOWSKI‐Modell bevorzugt angewendet werden.
Dependence of doping element incorporation on temperature in the chemical vapour deposition of epitaxial silicon (III). Empirical incorporation characteristic of the Si‐P‐H system
Authors: Kühne H.
Published: July 2007

The shape of the empirical incorporation characteristic of phosphorus in epitaxial silicon, deposited from silane‐phosphine‐hydrogen mixtures, shows two branches with different incorporation dependences on temperature (incorporation enthalpies). In the lower phosphorus‐concentration range (N < 1018) the experimentally determined value of incorporation enthalpy can be explained as a complex quantity, including the enthalpies of the two phosphorus hydrides PH3 and PH2, the latter of which is formed by the partial decomposition of phosphine (PH3) at deposition temperatures. — In the upper phosphorus‐concentration range (N > 1018) the incorporation equilibrium of the dimeric phosphorus molecules, formed by the nearly complete decomposition of phosphine, is reflected in the incorporation enthalpy of the empirical incorporation characteristic.
Determination of lattice parameters at thin epitaxial layers by RHEED
Authors: Tempel A. , Schumann B.
Published: July 2007

A simple method is described for measurement of lattice parameters of thin heteroepitaxial layers by RHEED technique using the substrate as a calibration substance. Results are presented for special cases of I–III–VI2 chalcopyrite type semiconductor epilayers on GaAs substrates. The accuracy of the method is in the order of about 5 · 10−3.
Optical defects in barium—strontium niobate single crystals
Authors: Kopylov Yu. L. , Kravchenko V. B. , Moiseev V. P.
Published: July 2007

The distributions of edge dislocations and residual mechanical stresses in BaxSr1‐xNb2O6 (BSN) crystals are investigated and the explanation of the nature of the “growth column” is proposed. The “growth column” is a defect zone going through all of the crystal and usually repeating in its cross‐section the contour of the seed crystal. The “growth column” boundary is the closed contour with extremely high edge dislocation density. These dislocations are connected with thermal stresses due to seed‐melt contact or abrupt crystal widening. Under proper crystal seeding and widening conditions one can obtain the BSN crystals with dislocation densities less than 10 cm−2 and without the “growth column”.

The method of chemico‐mechanical polishing of BSN crystals not forming a defect layer on the surface of the crystals have been developed. The high temperature diffusion annealing is shown to eliminate the growth striae in BSN crystals.
Cryoscopic Investigation of Lead Oxide Mixtures with Garnet Forming Oxides, Garnets, and Related Oxide Compounds
Authors: Fischer K.
Published: July 2007

The freezing point depression of PbO as solvent caused by the trivalent oxides and oxide compounds Fe2O3, Ga2O3, Al2O3, Bi2O3, Y2O3, Gd2O3, La2O3, YFeO3, Fe3O4, Y3Fe5O12, Gd3Ga5O12, and PbFe12O19 allows to determine the number of particles which are formed from these compounds in the diluted solutions. — We have measured the liquidus temperatures of binary mixtures with the help of a DTA‐equipment. In this way the cryoscopic constant K̄c = 121 ± 16 K · kg · mole−1 of PbO was determined by addition of ZnO, Cu2O, PbSO4, and PbF2, respectively. The experimental results show that the oxides and oxide compounds dissociate in particles which contain only one cation of the solved compound.
Basic Processes of Creep and their Investigation in the EM
Authors: Myshlyaev M. M.
Published: July 2007

The experimental data on the dislocation structure, its evolution and the mechanical behavior of the materials are considered at “moderate” and “elevated” temperatures. Possible schemes of the processes are represented.
Principles of the Design of Straining Stages
Authors: Messerschmidt U. , Appel F.
Published: July 2007

The paper describes the elastic properties of tensile stages for the HVEM. The quality of the force control depends on the accuracy of the drives related to the maximum elongation as well as on the elastic compliance of the stage. The best accuracy of the load is obtained in soft stages. The fundamental operation of a soft and a hard stage is reviewed. These stages use a special thermal drive.
The Influence of the Specimen Surface on Thermally Induced Structural Changes
Authors: Köster U.
Published: July 2007

Transmission electron microscopy has been particularly fruitful for studying phase transformations and other thermally induced structural changes. Investigations of such reactions can be carried out either by in‐situ hot stage electron microscopy using thin foils or by monitoring the structure after various times of annealing of bulk specimens outside the microscope. Observations after annealing clearly provide no information about the temporal relationship between changes which have occurred. Dynamic studies in the microscope are capable of providing this information, however, the proximity of the foil surface is a complicating factor.
On the characterization of electrically active inhomogeneities in semiconductor silicon by charge collection at schottky barriers using the SEM‐EBIC (I). Fundamentals and contrast due to macroscopical inhomogeneities
Authors: Kittler M.
Published: July 2007

The physical processes are explained for understanding of the EBIC‐method with direct irradiated schottky barriers, followed by description of preparation. The imagening of macroscopical inhomogeneities (striations, lifetime‐striae) is shown as an application in this Ist part. Finally contrasts are discussed, which are caused by preparation or by surface unevenness respectively, but not by inhomogeneities of the material.
The growth of HgI2 crystals
Authors: Gospodinov M.
Published: July 2007

The paper presents a system for αHgI2 crystal growth by the temperature oscillation method. The system has a capability of crystal growing at an excess I2 or Hg vapour pressure. Optimum conditions for producing crystals up to 2 cm3 by volume have been established. The crystals grown at an excess I2 vapour pressure have higher resistivity and higher drift electron and hole mobilities — μe = 120 cm2 V−1 s−1 and μh = 6 cm2 V−1 s−1, respectively.