Academic literature on the topic 'CU 3200'

The infrared photoinduced absorption (PA) spectrum of the semiconducting tetragonal phase of YBa 2 Cu 3 O 7−y ( y = 0.79 ÷ 0.85) is investigated in the 3200–350 cm −1 spectral range at low temperature (34 k). A broad electronic band is observed at 0.13 eV and is attributed to long lived metastable hole states generated by photoexcitation. Two PA phonon bands observed at 435 and 510 cm −1 correspond to totally symmetric modes of 1-2-3 involving Cu-O vibrations parallel to c axes. A vibronic activation mechanism is proposed in order to account for their IR activity and the nature of the .13eV midgap hole state is discussed in this framework.

Lake Caviahue, in Patagonia (Argentina), is a very acid water body (Patagonia, Argentina) due to the influx of volcanic fluids. Over the past 18 years, the lake has been progressively alkalinizing and pH is close to the ferric iron precipitation threshold (pH>3,0). Should iron precipitate, wáter and sediment composition will be altered. To set a baseline, trace metal partitioning (Cu, Cd, Cr, Pb, Zn and Mn) was studied for three sediment cores (0 to 16 cm depth) at three sampling stations using a sequential extraction procedure (SEP) and the acid volatile sulfide/simultaneously extracted metals (AVS/SEM) protocol. The total metals content of the sediments ranged between 0 to 408 μg g-1 of dry sediment, with Pb>Cr>Mn>Cu>Zn>Cd. No Cd was measured above the limit of detection. The sediment was richest in Mn and Cr, two non-toxic metals at the pH / Eh combination of the lake basin. Total Pb was at a moderate contamination level although it is associated with the most recalcitrant fraction and therefore has low mobility. The sediment fractions with higher metal content were the oxidizable and residual, the former commonly associated with labile organic matter and pyrite while the latter are related to recalcitrant organic matter and rock forming minerals. In addition, a high correlation was found between Cr, Pb and Mn,thus these metals may be subject to analogous precipitation processes and possibly to co-variation in the volcano effluents. Furthermore, no metals were detected in the exchangeable/carbonates fraction, which is the most labile of all the sediment fractions. The metal content in (SEM) was likewise below the toxicity thresholds of two international sediment quality guidelines and the ratio AVS/SEM was over one, indicative of non-toxicity. Both results indicate that metal mobility in the acidic sediments of lake Caviahue is very low.

Laser cladding of a Ni based powder on Cu-Ni-Al or cast iron was performed with a 4kW continuous Nd: YAG laser. The Cu-Ni-Al and cast-iron substrates are used for their thermal properties in glass mold industry. But the issue of these materials is their lack of resistance on corrosion and abrasion. The role of the Ni based alloy is to protect the mold without affecting its thermal properties (Heat Affected Zone (HAZ)). The purpose of this research is to produce a well bonded Ni based melted powder without pores or cracks on a non-planar surface (curvilinear section). An investigation of the impact of the processing parameters, power (1500-3200 W), scanning speed (2.5-10 mm/s) and powder feeding rate (24.5-32.5 g/min) on the bonding quality, the porosity propagation and HAZ appearance is performed. The used methods are neutronography, Scanning Electron Microscopy, Energy Dispersive Spectroscopy and Electron BackScatter Diffraction (EBSD). These multi-scale techniques are obviously complementary. Neutronography is a well-adapted non-destructive method to observe the porosity in the volume thanks to the contrast between materials. EBSD analysis allows us to analyze the microstructural evolution of the coating notably by observing the dendrites growth. This same method also permits to observe the HAZ nature according to the laser cladding parameters. Those methods allowed to optimize the processing parameters in a way to obtain perfect bonding, to avoid porosity propagation and to limit the HAZ emergence.

In this numerical study, 4 types of hybrid nanofluid, including Ag-MgO/water, TiO2-Cu/water, Al2O3-CuO/water, and Fe3O4-multi-wall carbon nanotube/water, have been considered potential working fluid in a single U-tube borehole heat exchanger. The selected hybrid nanofluid is then analyzed by changing the volume fraction and the Reynolds number. Based on the numerical results, Ag-MgO/water hybrid nanofluid is chosen as the most favorable heat carrier fluid, among others, considering its superior effectiveness, minor pressure drop, and appropriate thermal resistance compared to the pure water. Moreover, it was indicated that all cases of Ag-MgO/water hybrid nanofluid at various volume fractions (from 0.05 to 0.20) and Reynolds numbers (from 3200 to 6200) could achieve better effectiveness and lower thermal resistances, but higher pressure drops compared to the corresponding cases of pure water. Nevertheless, all the evaluated hybrid nanofluids present lower coefficient of performance (COP)-improvement than unity which means that applying them as working fluid is not economically viable because of having higher pressure drop than the heat transfer enhancement.

The synthesis of metallophthalocyanines (M [Formula: see text] Co, Cu, Mn) bearing four ethyl 7-oxy-4,8-dimethylcoumarin-3-propanoate moieties was performed. These novel compounds were characterized by elemental analysis, [Formula: see text]H-NMR spectroscopy, FT-IR, UV-vis and mass spectral data. DC and AC electrical properties of the films of metallophthalocyanines were investigated in the temperature range of 295–523 K. AC measurements were performed in the frequency range of 40–10[Formula: see text] Hz. Activation energy values of the films took place between 0.55 eV–0.93 eV. Impedance spectroscopy measurements revealed that bulk resistance decreases with increasing temperature, indicating semiconductor properties. DC conductivity results also supported this result. Their gas sensing properties were also investigated for the vapors of Volatile Organic Compounds (VOCs), [Formula: see text]-butyl acetate (200–3200 ppm) and ammonia (7000–56000 ppm) between temperatures 25–100°C. Sensitivity and response times of the films for the tested vapors were reported. The results were found to be reversible and sensitive to the vapors of [Formula: see text]-butyl acetate and ammonia. It was found that Mn(OAc)Pc showed better sensitivity than CoPc and CuPc for [Formula: see text]-butyl acetate vapors at all measured vapor concentrations and temperatures. Mn(OAc)Pc also showed better sensitivity than CoPc and CuPc for ammonia vapors at 22°C.

Malachite Cu2(CO3)(OH)2 is a common hydroxycarbonate that contains about 15.3 wt % H2O. Its structural chemistry sheds light on other hydroxyl minerals that play a role in the water recycling of our planet. Here using Raman and infrared spectroscopy measurements, we studied the vibrational characteristics and structural evolution of malachite in a diamond anvil cell at room temperature (25 °C) up to ~29 GPa. Three types of vibrations were analyzed including Cu–O vibrations (300–600 cm−1), [CO3]2− vibrations (700–1600 cm−1), and O–H stretches (3200–3500 cm−1). We present novel observations of mode discontinuities at pressures of ~7, ~15, and ~23 GPa, suggesting three phase transitions, respectively. First, pressure has a great effect on the degree of deformation of the [CuO6] octahedron, as is manifested by the various shifting slopes of the Cu–O modes. [CuO6] deformation results in a rotation of the structural unit and accordingly a phase transition at ~7 GPa. Upon compression to ~15 GPa, the O–H bands redshift progressively with significant broadness, indicative of an enhancement of the hydrogen bonding, a shortening of the O···O distance, and possibly somewhat of a desymmetrization of the O–H···O bond. O–H mode hardening is identified above ~15 GPa coupled with a growth in the amplitude of the lower-energy bands. These observations can be interpreted as some reorientation or reordering of the hydrogen bonding. A further increment of pressure leads to a change in the overall compression mechanism of the structure at ~23 GPa, which is characterized by the blueshift of the O–H stretches and the softening of the O–C–O in-plane bending bands. The hydrogen bonding weakens due to a substantial enhancement of the Cu–H repulsion effect, and the O···O bond length shows no further shortening. In addition, the change in the local geometry of hydrogen is also induced by the softening of the [CO3]2− units. In this regard we may expect malachite and other analogous hydroxyl minerals as capable of transporting water downward towards the Earth’s transition zone (~23 GPa). Our results furnish our knowledge on the chemistry of hydrogen bonding at mantle conditions and open a new window in understanding the synergistic relations of water and carbon recycling in the deep Earth.

Peru is mining country with a great diversity of mineral resource. The high grade ores are declining, and there is a need to implement new techniques for recycling metals (Cu, Au, Zn, Pb, etc) from low-grade ores. In order to answer this question, the bioleaching of copper from sulphide ore (FeS2 45.30%, CuFeS2 1.90%, ZnS 8.90%, FeAsS 13.12%, PbS 3.69%) was evaluated with different concentrations of Fe2+ using an iron-oxidizing native microbial consortium.The samples were collected from drainage acid mine (4100 m.a.s.l.) located in the south of Huancavelica region and the sample of ore from middle Huaraz region (3200 m.a.s.l.). Microorganisms were isolated in 9k medium at pH 1.8, 22oC. Bioleaching test were performed in two consecutive steps to 150 rpm at 22oC, monitoring pH, ORP (mV). Assays varying the concentration of Fe2+ (0 mM – 53 mM) were performed with a pulp density of 1% and 2% at each step, and with an inoculum 10% (v/v) to a microbial concentration of 108 cel/mL.We isolated a microbial consortium after 8 weeks with presence of bacteria Acidithiobacillus ferrooxidans-like. In assays, copper was solubilized. The microbial concentration in the tests was (2x107- 4x107cel/mL). In the first stage, the test with 21 mM Fe2+ recovered 62% copper. In the next step, with the bacterial concentration of the first step, bioleaching time is reduced by 22% for copper recovery (63%) in absence of Fe2+.With these data, we observed that the addition of iron is not necessary in a stage adaptation when the mineral contain iron.

O plantație pură de stejar roșu, 2 x 1 m (5000 puieți ha-1), a fost instalată în parcul castelului Mikes (Zăbala, județul Covasna) în primăvara anului 2012. Condițiile ecologice locale (temperatura medie anuală 7,6 oC, precipitațiile medii anuale 616 mm, Districambosol tipic) sunt de bonitate mijlocie pentru stejarul roșu, ca și pentru vegetația naturală (goruneto-făgete). O lucrare de curățiri a fost aplicată în cele două suprafețe de probă (SP) de cercetare / demonstrative instalate în aprilie-mai 2019, care a prezentat câteva caracteristici interesante înainte de intervenția la vârsta de 7 ani: (i) desime 4692 arb ha-1 (SP1) și 3692 arb ha-1 (SP2); (ii) diametrul mediu aritmetic 4,84 cm (SP1) și 5,01 cm (SP2); peste 40% din arbori, în ambele SP, au avut diametre peste 5 cm (creșterea medie în diametru peste 7 mm an-1); (iii) diametrul mediu al suprafeței de bază: 5,05 cm (SP1) și 5,12 cm (SP2); (iv) înălțimea medie aritmetică: 6,48 m (SP1) și 6,77 m (SP2); peste 40% din arbori, în ambele SP, au avut peste 7 m înălțime (creșterea medie în înălțime peste 1 m an-1); (v) înălțimea corespunzătoare diametrului mediu al suprafeței de bază: 6,75 m (SP1) și 6,88 m (SP2). Lucrarea de curățiri a fost predominant de jos și de intensitate puternică (SP1), respectiv moderată (SP2), pe număr de arbori, și moderată (ambele SP) pe suprafață de bază. Arboretul rămas, în ambele SP, este încă des (desimea peste 3200 arb ha-1; suprafața de bază peste 7 m2 ha-1), cu diametre medii și înălțimi medii mai mari decât cele inițiale, respectiv indici de zveltețe mai mici. Numărul de „potențiali” arbori de viitor, aleși și însemnați cu vopsea înainte de curățire pe baza criteriilor vigoare-calitate-spațiere, a fost mai mare (538 arb ha-1 în SP1, 461 arb ha-1 în SP2) decât în alte țări europene (maximum 400 arb ha-1). Deoarece o parte din acești arbori prezintă înfurciri la înălțimi sub 4 m, doar 150-200 arb ha-1 din aceste exemplare vor fi selectate de-a lungul fazei de păriș, când se dorește aplicarea unei silviculturi pe arbore, care urmărește creșterea liberă (fără competiție la nivelul coroanei) a acestora.

The effects of tungsten contents (80-88wt.%) and different Ni:Cu ratio (7:3-3:7 by weight) on microstructure and dynamic mechanical properties of W-Ni-Cu alloys were investigated. Results show that at the same sintering conditions, with tungsten content increasing from 80 wt % to 88 wt %, tungsten grains increase slightly. Spherical and more uniform tungsten grains distribute in matrix phase in 85W alloys with Ni:Cu ratio of 1:1 than that of 3:7 and 7:3. The results also show that the dynamic yield strength of W-Ni-Cu alloys goes up with tungsten content increasing, but keep similar deformation capability. With strain rate increasing in the range of 2600-4200s-1, 85W displays strain rate softening effect. Adiabatic shear bands are formed at strain rate over 3200s-1.

Pengolahan biji tembaga menjadi tembaga banyak dilakukan menggunakan proses pemekatan melelui pencucian dan pemisahan secara fisik dengan hasil yang tidak maksimal karena sebagian logam ikut terbuang bersama pengotor logam yang lain, diantaranya kadmium ke dalam ekosistem darat dan perairan.Telah dilakukan penelitian tentang pengaruh bahan elektroda pada pengambilan tembaga dan kadmium dari campuran dengan komposisi elektrolit CuSO4 dan CdSO4 secara elektrolisis. Sel elektrolisis menggunakan variasi bahan elektroda tembaga- karbon (Cu-C), seng - karbon (Zn-C) dan karbon-karbon (C-C). Elektrolisis dijalankan dengan potensial terpasang tetap pada temperatur kamar selama 2 jam.Hasil penelitian diperoleh bahwa kuantitas pengendapan tembaga terbaik pada elektrode (Zn-C) dapat menurunkan kadar Cu2+ dari 63,5 ppm menjadi 41,5 ppm dengan efisiensi arus 32,0 %, dan elektrode (Cu-C) dapat menurunkan kadar Cd dari 112,4 ppm menjadi 94,4 ppm dengan efisiensi arus 3,8 %Kata kunci : tembaga, kadmium, elektrolisis, bahan elektroda

Diese Untersuchung beschäftigt sich mit der Frage, welche Krankheitskonzepte depressiven Patienten (ICD-10) und ihre Partnern haben und welche Behandlungs-erfahrungen gemacht wurden. Das Ziel der Untersuchung besteht darin, auf der Grundlage einer ressourcenorientierten explorativen Sichtweise die rehabilitativen Möglichkeiten für depressive Patienten und ihre Partner zu erweitern und geschlechtsspezifische Unterschiede einzubeziehen. Die Forschung zur Compliance macht deutlich, dass die Übereinstimmung der Krankheitskonzepte die Behandlungsergebnisse entscheidend verbessern kann. Es wurde den Fragen nachgegangen, worin sich die Attributionen auf Krankheitsursachen bei Patienten und ihren Partnern unterscheiden und welche Auswirkungen sich für das partnerschaftliche Unterstützungsverhalten ergeben. Zudem wurden die motiva-tionalen Schemata auf der Grundlage der Konsistenztheorie (Grawe, 1998; 2004) erhoben, Geschlechtsunterschiede und die Partnerschaftsqualität beachtet. Als Theorien wurden zum Beispiel die Theorie der wahrgenommenen Verantwortlichkeit (Weiner, 1986) und der gelernten Hilflosigkeit (Seligman, 1975; Abramson, Seligman & Teasdale, 1978) und daraus Fragestellungen entwickelt. Diese Arbeit hat sich die Aufgabe gestellt, die persönlichen Besonderheiten der depressiven Patienten und ihrer Partner zu beachten. Die Methodik besteht aus einem semistrukturierten qualitativen Interview sowie standardisierten Fragebögen. Es wurden 46 depressive Patienten und 46 Partner einer Psychiatrie- und Psychotherapiestation untersucht. Es konnten verschiedene Zusammenhänge zwischen der Partnerschaftsqualität, der partnerschaftlichen Unterstützung, den Einstellungen und motivationalen Schemata gefunden werden. Die Ergebnisse zeigen, dass geschlechtsspezifische Unter-schiede bei Patienten und Partnern viel stärker in der Therapie beachtet werden sollten. Es konnte gezeigt werden, dass sich innerhalb der diagnostischen Zuord-nung einer Depression sehr verschiedene individuelle Krankheitskonzepte bei Patienten und bei den Partnern ergeben. Es lassen sich jedoch auch Probleme aufzeigen, die mit einem leitlinienorientierten Vorgehen in der Psychotherapie verbunden sind. Die qualitative Befragung konnte innere Prozesse und Entwicklungen gut sichtbar machen, die quantitative Methodik der Fragebögen bildete Status und überdauernde Motive gut ab. Mögliche Anwendungen und Impli-kationen für die klinische Praxis sowie die Einbeziehung der Partner werden diskutiert.
This study is employed with the questions what kind of illness representations and experiences of examination are generated by depressive patients (ICD-10) and their partners. The goal is existed in finding more possibilities in rehabilitation and therapy for the couples are based on resources and sex differences. The research of compliance comes to the resolution that the agreement in illness representations is able to improve the outcomes of therapy. Therefore, the questions are, which differences in illness representations by patients and partners, expectations, solutions of support by the couples, males and females can be found and what are the consequences for compliance and their relationship. Then, the motivational schemata based on the consistence-theory (Grawe, 1998; 2004) were considered. On basic were included the theories of perceived responsibility (Weiner, 1986) and learned helplessness (Seligman, 1975; Abramson, Seligman & Teasdale, 1978) and then developed individual questions. The method is a mixed design in qualitative (semi-structured interview) and quantitative instruments (tests). Data are used from 92 persons, 46 patients they are in clinical treatment and their partners. There are found that quality of partnership is associated with support, the expectations, attitudes and individual motivational schemata of the persons. Sex differences should be stronger observed in treatment. Turns out, into the notation “depression”, there are different individual illness representations of patients and their partners. The application of guideline-oriented procedures in psychotherapy has been criticized. Qualitative interviews were appropriate to describe processes and developments, quantitative tests were appropriate to expose the status and outlasting motives. Results are presented in terms of their implications for supporting treatment and involving partners into this process.

alpha-Interferon (alpha IFN) ist derzeit die Grundlage jeder Behandlung der chronischen Hepatitis C. Zu den unerwünschten Effekten von alpha-IFN gehört die Entwicklung psychiatrischer Nebenwirkungen, die sich häufig als Depressivität äussern. Deren Häufigkeit, Schweregrad und Behandlungsbedarf wurden jedoch bisher nur unzureichend erforscht. 66 Patienten mit chronischer Hepatitis C wurden in einer Pilotstudie mit alpha-IFN als Monotherapie (3x3 MU/ Woche) oder in Kombination mit Ribavirin (1000-1200 mg/ Woche) behandelt. Sämtliche Patienten wurden vor, während und nach der Therapie hinsichtlich ihrer Depressivität beurteilt. Dies geschah sowohl im persönlichen Gespräch als auch mit Hilfe der Selbstbeurteilungsinstrumente ADS (Allgemeine Depressions Skala) und BDI (Beck Depressions Inventar). Die Ausgangsdepressivität der Hepatitispatienten entsprach dem gesunden Eichkollektiv. Im Gesamtdurchschnitt stieg die Depressivität innerhalb der ersten drei Behandlungsmonate um 5,15 (+/-8,94) Punkte auf der ADS und um 3,85 (+/-6,94) Punkte im BDI an. Weniger als ein Drittel der Patienten erlebte keine Zunahme der Depressivität. Patienten, die vor Therapiebeginn eine geringe Depressivität aufwiesen, beschrieben eine stärkere Zunahme depressiver Symptome als Patienten, die initial als depressiv beurteilt wurden. Letztere blieben während des Therapieverlaufs jedoch weiterhin depressiver als die anfangs nicht-depressiven Patienten. Vier Patienten wurden wegen schwerster depressiver Nebenwirkungen stationär psychiatrisch behandelt. Es wurde kein signifikanter Zusammenhang zwischen Ausgangsdepressivität und Behandlungserfolg festgestellt. Um stark gefährdete Patienten frühzeitig zu erkennen, wird vorgeschlagen, sowohl ADS als auch BDI vor und während der Therapie zu verwenden. Anhand eines ADS-Grenzwertes von > 17 vor und >= 30 während der Behandlung konnten 75% derjenigen Patienten, die im Verlauf der Therapie mit alpha-IFN schwerste depressive Symptome entwickelten, identifiziert werden.
Interferon-alpha (alpha-IFN) is presently the mainstay of the treatment of chronic hepatitis C. Side effects include a range of psychiatric symptoms, most frequently the development of depressive symptoms. Their incidence, severity and necessity for therapeutic intervention has not yet been sufficiently studied. 66 patients with chronic hepatitis C were enrolled in a pilot study and treated with either alpha-IFN alone (3x3 MU/ week) or in combination with Ribavirin (1000-1200 mg/ week). All patients went through repeated evaluations concerning their depressive symptoms before, during, and after treatment. Apart from individual interviews with the psychosomatic staff, the psychometric instruments used were the ADS (Allgemeine Depressions Skala, the German version of the Center for Epidemiological Studies Depression Scale, CES-D) and the BDI (Beck Depression Inventory). The initial depression score of the hepatitis C patients was comparable to that of a healthy population. On average, depression scores increased by 5,15 points (+/-8,94) on the ADS and 3,85 points (+/-6,94) on the BDI during the first 3 months of treatment. Less than a third of all patients did not show an increase of depressive symptoms. Patients with an initially low depression score experienced a greater increase of depressive symptoms than patients initially diagnosed as depressive. Nevertheless, the latter patients remained more depressive throughout the study period. Four patients developed severe depressions that necessitated admission to a psychiatric clinic. There was no significant correlation between the initial depression score and the treatment response. In order to recognize those patients at high risk for the development of severe depressions at an early stage, the author proposes the use of ADS and BDI both before and during treatment with alpha-IFN. Using a cut-off score of more than 17 points on the ADS before, and >=30 points during treatment, 75% of all patients developing severe depressions during treatment with alpha-IFN could be identified.

The present study focuses on the effect of alloying elements, namely, strontium (Sr), titanium (Ti), zirconium (Zr), scandium (Sc) and silver(Ag) individually or in combination, on the performance of a newly developed Al-2%Cu based alloy. A total of thirteen alloy compositions were used in the study. Tensile test bar castings were prepared employing the low pressure die casting (LPDC) technique. The test bars were solution heat treated at 495°C for 8 hours, followed by quenching in warm water, and then subjected to different isochronal aging treatments using an aging time of 5 hours and aging temperatures of 155°C, 180°C, 200°C, 240°C and 300°C. Tensile testing of as-cast and heat-treated test bars was carried out at room temperature using a strain rate of 4 x 10-4s-1. Five test bars were used per alloy composition/condition. Hardness measurements were also carried out on these alloys using a Brinell hardness tester. The microstructures of selected samples were examined using optical microscopy and electron probe microanalysis (EPMA). The results showed that adding Ti in the amount of 0.15 wt% in the form of Al-5%Ti-1%B master alloy is sufficient to refine the grains in the cast structure in the presence of 200 ppm Sr (0.02 wt%). Addition of Zr and Sc did not contribute further to the grain refining effect. The main role of addition of these two elements appeared in the formation of complex compounds with Al and Ti. Their presence resulted in extending the aging temperature range before the onset of softening. Mathematical analysis of the hardness and tensile data was carried out using the Minitab statistical software program. It was determined that the alloy containing (0.5wt% Zr + 0.15wt% Ti) is the most effective in maximizing the alloy tensile strength over the range of aging temperatures, from 155°C to 300°C. Addition of Ag is beneficial at high aging temperatures, in the range of 240°C-300°C. However, it is less effective compared to the (Zr + Ti)-containing alloy. Addition of Sc does not appear to improve the alloy performance beyond what is achieved by the addition of Zr. From a plot of ultimate tensile strength (UTS) versus percent elongation (%El) values, the following equation was obtained to represent the strength-ductility relationship: UTS (MPa) = -32 %El + 393 with a fit of R2 = 0.83. Cette étude se concentre sur l’effet les éléments d’alliage, à savoir, le strontium (Sr), le titane (Ti), le zirconium (Zr), le scandium (Sc) et l'argent (Ag), individuellement ou en combinaison, sur la performance d’un nouvel alliage Al-2%Cu développé récemment. Treize compositions d'alliages sont utilisées dans l'étude. Des éprouvettes d’essai ont été préparées en utilisant la technologie de coulée à basse pression (LPDC). Les éprouvettes ont été mises dans une solution à 495 ° C pendant 8 heures suivi d'une trempe à l'eau tiède, puis soumis à différents traitements de vieillissement isochrones durant 5 heures, à différentes températures 155°C, 180°C, 200°C, 240°C et 300°C. Les essais en traction des échantillons ainsi traités, ont été effectués, à température ambiante en utilisant une vitesse de déformation de 4 x 10-4s-1. Cinq éprouvettes ont été utilisées par composition d’alliage / température de vieillissement. Des mesures de dureté ont également été effectuées sur ces alliages à l'aide d'un testeur de dureté Brinell. Les microstructures des échantillons sélectionnés ont été examinées par microscopie optique et microanalyse à sonde électronique (EPMA). Les résultats montrent que l'ajout de Ti en une proportion de 0,15% en poids sous forme d’alliage Al-5% Ti-1% B est suffisant pour affiner les grains de la structure de coulée en présence de 200 ppm de Sr (0,02% en poids). L’ajout de Zr et de Sc ne contribue pas davantage à l'effet d'affinage du grain. Le rôle principal de l'addition de ces deux éléments est apparu dans la formation de composés complexes avec Al et Ti. Leur présence a donné lieu à l'extension de la plage de températures de vieillissement avant le début de ramollissement. L'analyse mathématique des données de dureté et de traction a été réalisée en utilisant le logiciel de statistique Minitab. Il a été déterminé que l'alliage contenant 0,5% en poids de Zr + 0,15% en poids de Ti est le plus efficace pour maximiser la résistance à la traction de l'alliage dans la plage de températures de vieillissement de 155 ° C jusqu’à 300 ° C. L'addition d’Ag est bénéfique à haute température de vieillissement dans la plage de 240 ° C-300 ° C. Cependant, il est moins efficace par rapport à l’alliage contenant l' Zr + Ti. L'addition de Sc ne semble pas améliorer les performances de l'alliage au-delà de ce qui est réalisé par l'addition de Zr. A partir d’une courbe de la résistance à la traction (UTS) versus les valeurs du pourcentage d'allongement (% El), nous avons obtenu l'équation suivante représentant la relation force-ductilité: UTS (MPa) = -32 % El + 393 avec un ajustement de R2 = 0.83.

It has been known for some time that an acid chloride 1 can be added to an alkyne 2 to give the β-chloro enone. Yasushi Tsuji of Kyoto University found (J. Am. Chem. Soc. 2009, 131, 6668) that with an Ir catalyst, the condensation of 1 with 2 could be directed to the furan 3. Huanfeng Jiang of the South China University of Technology described (Organic Lett. 2009, 11, 1931) a complementary route to furans, Cu-mediated condensation of a propargyl alcohol 4 with the diester 5 to give 6. Bruce A. Arndtsen of McGill University developed (Organic Lett. 2009, 11, 1369) an approach to pyrroles such as 9, by condensation of an α,β-unsaturated α-cyano imine 7 with the acid chloride 8. Thomas J. J. Müller of Heinrich-Heine-Universität Düsseldorf observed (Organic Lett. 2009, 11, 2269) the condensation of an acid chloride 11 with a propargyl amine 10, leading to the iodo pyrrole 12. John A. Murphy of the University of Strathclyde uncovered (Tetrahedron Lett. 2009, 50, 3290) a new entry to the Fischer indole synthesis, by Petasis homologation of a hydrazide 13. Dali Yin of Peking Union Medical College took advantage (Organic Lett. 2009, 11, 637) of the easy sequential displacement of the fluorides of 15, leading, after acid-catalyzed cyclization, to the indole 17. Kang Zhao of Tianjin University extended (Organic Lett. 2009, 11, 2417; Organic Lett. 2009, 11, 2643) his studies of oxidation of an enamine 18 to the 2H -azirine, that on heating cyclized to the indole 19. Peter Wipf of the University of Pittsburgh established (Chem. Commun. 2009, 104) a microwave-promoted indole synthesis, illustrated by the intramolecular Diels-Alder cyclization of 20 to 21. A review delineating all nine types of indole syntheses will appear shortly in Angewandte Chemie . Fushun Liang and Qun Liu of Northeast Normal University demonstrated (J. Org. Chem. 2009, 74, 899) that the readily-prepared ketene thioacetal 22 condensed with NH3 to give the pyridine 23. Sundaresan Prabhakar and Ana M. Lobo of the New University of Lisbon observed (Tetrahedron Lett. 2009, 50, 3446) that the addition of the alkoxy propargyl amine to the alkyne 25 gave a Z alkene, that on warming rearranged to the pyridine 26.