738 research outputs found

    El seminario de San Francisco de Paula de Zaragoza (II)

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    ADSORBSI ION LOGAM DARI LIMBAH ELEKTROPLATING MENGGUNAKAN ABU BAGASE

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    Adsorbsi ion logam dari limbah electroplating telah diteliti melalui kajian eksperimental Vanabel yang dipelajari adalah waktu pengadukan, ph limbah dan berate abu bagas terhadap proses, adsorbsi. Limbah awal diatur phnya sesuai dengan variable tertentu, kemudian ditambahk-m abu bagase dengan variasi berat. Selanjutnya limbah diaduk selama waktu tertentu sehingga terjadi kontak antara adsorbent dengan adsorbat, Setelah itu larutan discoing untuk diambil filtratnya guna dianalisa Penelitian ini menunjukkan bahwa semakin besar berat abu bagase don semakin lama waktupengaduk-M maka k-onsentrasi logam yang dapat diadsorbsi semakin besar. Tetapi untuk ph pads masing-masing logam berbeda-beda pxnyerapannya. Untuk khrom pads ph 8-9 sebesar 106,23 mg/L, ferro pads ph dibawah 8 sebesar 4,24 mg/L, dan Hiked pads ph 9-11 sebesar 1,42 mg/L

    Evidence for power-law frequency dependence of intrinsic dielectric response in the CaCu3_{3}Ti4_{4}O12_{12}

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    We investigated the dielectric response of CaCu3_3Ti4_4O12_{12} (CCTO) thin films grown epitaxially on LaAlO3_3 (001) substrates by Pulsed Laser Deposition (PLD). The dielectric response of the films was found to be strongly dominated by a power-law in frequency, typical of materials with localized hopping charge carriers, in contrast to the Debye-like response of the bulk material. The film conductivity decreases with annealing in oxygen, and it suggests that oxygen deficit is a cause of the relatively high film conductivity. With increase of the oxygen content, the room temperature frequency response of the CCTO thin films changes from the response indicating the presence of some relatively low conducting capacitive layers to purely power law, and then towards frequency independent response with a relative dielectric constant ϵ102\epsilon'\sim10^2. The film conductance and dielectric response decrease upon decrease of the temperature with dielectric response being dominated by the power law frequency dependence. Below \sim80 K, the dielectric response of the films is frequency independent with ϵ\epsilon' close to 10210^2. The results provide another piece of evidence for an extrinsic, Maxwell-Wagner type, origin of the colossal dielectric response of the bulk CCTO material, connected with electrical inhomogeneity of the bulk material.Comment: v4: RevTeX, two-column, 9 pages, 7 figures; title modified, minor content change in p.7, reference adde

    Caracterización selvícola de las masas monoespecíficas de pino laricio en Cataluña

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    This study presents a silvogenetic typology of single-species stands of Pinus nigra in Catalonia (NE of Spain) based on the information supplied by the Second National Forest Inventory. Results of factor analysis applied to dendrometric variables show nine different stand types, identified mainly from variables related to diameter distribution and stand stocking. The character of uneven-aged stands, present in five of the groups though with different features, was analyzed using a truncated Weibull distribution. The typology, which is managed by computing regeneration levels and diametric classes, encompasses different developmental stages and allows the diagnosis of compromised situations in terms of stand persistence caused by low or high stocking.En el presente trabajo se ha abordado, a partir de la información suministrada por el Segundo Inventario Forestal Nacional, la caracterización de las masas monoespecíficas de pino laricio en Cataluña (NE de España), formalizándola en una tipología de enfoque silvogenético. Basándose en los resultados obtenidos del análisis factorial realizado sobre variables dasométricas, los categoremas de la tipología se articularon sobre aspectos concernientes a la distribución diamétrica y espesura del rodal, identificándose nueve tipos. El carácter irregularizado, presente en cinco de ellos aunque con rasgos diferentes, se examinó a través de la distribución deWeibull truncada. La tipología, que se maneja computando tan sólo el nivel de regenerado y los diámetros de los pies inventariables, contempla los distintos estadios evolutivos y permite diagnosticar situaciones comprometidas en cuanto a la persistencia de la masa, bien causadas por deficientes estados de espesura o por falta de regenerado

    depressive spectrum disorders in cancer prevalence risk factors and screening for depression a critical review

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    AbstractBackground: Although depression and mood-related disorders are common in persons with cancer, these conditions remain frequently overlooked in clinical practice. Negative consequences of depressive disorder spectrum have been reported (e.g. suicidal ideation, increase physical complications and somatic symptoms, negative influence on prognosis), indicating the need for routine screening, assessment and management.Methods: A search of the major databases (Medline, Embase, PsycLIT, PsycINFO, and the Cochrane Library) was conducted on the reviews and meta-analyses available in order to summarize relevant data concerning depressive disorders spectrum in terms of prevalence, risk factors, and screening and assessment among patients with cancer across the trajectory of the disease.Results: The data show a prevalence of depression and depressive disorders between 5% and 60% according to the different diagnostic criteria, the tools used in the studies (e.g. semi-structured psychiatric interview and psycho..

    El Seminario de San Francisco de Paula de Zaragoza (I)

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