Pemanfaatan Kulit Singkong sebagai Bahan Baku Karbon Aktif

Karbon aktif merupakan produk dari proses aktivasi karbon yang kemampuan penyerapannya lebih tinggi dan memiliki kegunaan lebih banyak daripada karbon biasa. Karbon aktif dapat mengadsorpsi gas dan senyawa-senyawa kimia tertentu atau sifat adsorpsinya selektif, tergantung pada besar atau volume pori-pori dan luas permukaan. Karbon aktif dapat dibuat dari karbon kulit singkong dengan cara dikarbonisasi untuk menghasilkan karbon pada suhu 2000C, 3000C, 4000C, 5000C, dan 6000C. Selanjutnya karbon diaktivasi secara kimia dengan larutan asam fosfat. Proses aktivasi kimia karbon kulit singkong dilakukan dengan merendam karbon kulit singkong dalam larutan H3PO4 2,5% selama 24 jam. Karbon aktif yang dihasilkan memenuhi standar (SNI) 06–3730-1995 dengan hasil pengujian kadar air antara 4,5% - 13% dimana standar SNI maksimum 15% dan kadar abu antara 1,5%-7,5% dimana standar SNI maksimum 10%, dan dan daya serap iodium antara 2.533,78 mg/g - 2.537,71mg/g dimana standar SNI maksimum 750 mg/g

Indispensable role of Mdm2/p53 interaction during the embryonic and postnatal inner ear development

p53 is a key component of a signaling network that protects cells against various stresses. As excess p53 is detrimental to cells, its levels are tightly controlled by several mechanisms. The E3 ubiquitin ligase Mdm2 is a major negative regulator of p53. The significance of balanced p53 levels in normal tissues, at different stages of lifetime, is poorly understood. We have studied in vivo how the disruption of Mdm2/p53 interaction affects the early-embryonic otic progenitor cells and their descendants, the auditory supporting cells and hair cells. We found that p53 accumulation, as a consequence of Mdm2 abrogation, is lethal to both proliferative progenitors and non-proliferating, differentiating cells. The sensitivity of postmitotic supporting cells to excess p53 decreases along maturation, suggesting that maturation-related mechanisms limit p53's transcriptional activity towards pro-apoptotic factors. We have also investigated in vitro whether p53 restricts supporting cell's regenerative capacity. Unlike in several other regenerative cellular models, p53 inactivation did not alter supporting cell's proliferative quiescence nor transdifferentiation capacity. Altogether, the postmitotic status of developing hair cells and supporting cells does not confer protection against the detrimental effects of p53 upregulation. These findings might be linked to auditory disturbances observed in developmental syndromes with inappropriate p53 upregulation.Peer reviewe

Pengaruh Penambahan Serbuk Ban Karet Pada Campuran Laston Untuk Perkerasan Jalan Raya

Pertumbuhan jumlah kendaraan berdasarkan data Badan Pusat Statistik (BPS) semakin meningkat dari tahun ke tahun. Dalam kurun satu tahun pertumbuhan kendaraan naik 10% atau sekitar 10 juta kendaraan dari tahun sebelumnya. Pertumbuhan jumlah kendaraan merupakan faktor utama kerusakan pada jalan, karena semaki nmeningkatnya jumlah kendaraan maka beban yang diterima oleh jalan akan melebihi beban rencana. Penelitian ini bertujuan untuk mengetahui pengaruh nilai sifat-sifat marshall dari penambahan serbuk ban karet serta dapat mengurangi nilai VMA sehingga kerusakan pada jalan raya bisa berkurang. Penelitian ini memanfaatkan ban bekas dalam bentuk serbuk untuk dijadikan bahan tambah (aditif) dalam campuran laston dengan menggunakan aspal Pen. 60-70. Penelitian ini menggunakan variasi kadar aspal 5%, 5,5%, 6%, dan 6,5% dengan variasi serbuk ban karet 1%, 2%, dan 3% dari berat aspal. Hasil penelitian menunjukkan nilai Void Filled semakin besar, sedangkan Void in Mixture (VIM) dan Void Mineral Aggregate (VMA) yang semakin kecil. Namun, untuk nilai flow dan Marshall Quotient (MQ) tidak memberikan hasil yang konstan. Penambahan serbuk ban karet juga dapat mengurangi penggunaan aspal dalam campuran laston

Resolved Young Binary Systems And Their Disks

We have conducted a survey of young single and multiple systems in the Taurus–Auriga star-forming region with the Atacama Large Millimeter Array (ALMA), substantially improving both the spatial resolution and sensitivity with which individual protoplanetary disks in these systems have been observed. These ALMA observations can resolve binary separations as small as 25–30 au and have an average 3σ detection level of 0.35 mJy, equivalent to a disk mass of 4 × 10−5 M ⊙ for an M3 star. Our sample was constructed from stars that have an infrared excess and/or signs of accretion and have been classified as Class II. For the binary and higher-order multiple systems observed, we detect λ = 1.3 mm continuum emission from one or more stars in all of our target systems. Combined with previous surveys of Taurus, our 21 new detections increase the fraction of millimeter-detected disks to over 75% in all categories of stars (singles, primaries, and companions) earlier than spectral type M6 in the Class II sample. Given the wealth of other information available for these stars, this has allowed us to study the impact of multiplicity with a much larger sample. While millimeter flux and disk mass are related to stellar mass as seen in previous studies, we find that both primary and secondary stars in binary systems with separations of 30–4200 au have lower values of millimeter flux as a function of stellar mass than single stars. We also find that for these systems, the circumstellar disk around the primary star does not dominate the total disk mass in the system and contains on average 62% of the total mass

Resolved Young Binary Systems And Their Disks

We have conducted a survey of young single and multiple systems in the Taurus–Auriga star-forming region with the Atacama Large Millimeter Array (ALMA), substantially improving both the spatial resolution and sensitivity with which individual protoplanetary disks in these systems have been observed. These ALMA observations can resolve binary separations as small as 25–30 au and have an average 3σ detection level of 0.35 mJy, equivalent to a disk mass of 4 × 10−5 M ⊙ for an M3 star. Our sample was constructed from stars that have an infrared excess and/or signs of accretion and have been classified as Class II. For the binary and higher-order multiple systems observed, we detect λ = 1.3 mm continuum emission from one or more stars in all of our target systems. Combined with previous surveys of Taurus, our 21 new detections increase the fraction of millimeter-detected disks to over 75% in all categories of stars (singles, primaries, and companions) earlier than spectral type M6 in the Class II sample. Given the wealth of other information available for these stars, this has allowed us to study the impact of multiplicity with a much larger sample. While millimeter flux and disk mass are related to stellar mass as seen in previous studies, we find that both primary and secondary stars in binary systems with separations of 30–4200 au have lower values of millimeter flux as a function of stellar mass than single stars. We also find that for these systems, the circumstellar disk around the primary star does not dominate the total disk mass in the system and contains on average 62% of the total mass

Análisis del avance en productividad en la industria manufacturera mexicana, 1929-1944

Este trabajo de investigación analiza el crecimiento en la productividad total de los factores (PTF) durante el período 1929-1944 y su importancia como fuente de crecimiento en la industria manufacturera mexicana. El análisis se realiza a nivel sectorial. La tarea principal del trabajo se enfoca en la estimación del crecimiento de la PTF, lo cual se lleva a cabo utilizando la metodología de Harberger denominada Método de Dos Deflactores, y cuya principal característica es que la cantidad de información requerida para calcular el crecimiento de la PTF es mucho más manejable –comparado con métodos tradicionales–, además de ser un método robusto y fácil de aplicar. Adicionalmente, el trabajo presenta un análisis empírico para apoyar la tesis de que el avance en la productividad fue una de las causas principales del proceso de sustitución de importaciones y del crecimiento observado en la industria manufacturera durante el período 1929-1939.The paper analyzes total factor productivity (TFP) growth during the period 1929-1944 and its importance as a source of growth in Mexican manufacturing. The analysis of the industry is done at sector level. The paper task focuses on the estimation of TFP growth, and this is done using Harberger’s methodology named the Two Deflator Method (2D), whose main characteristic is the realization that the amount of information required to compute the TFP growth rate is much more manageable compared to traditional methods, besides being a very robust and easily applicable method. In addition, the paper presents an empirical analysis to support the thesis that total factor productivity advance was one of the main causes to explain import substitution and growth in manufacturing during the period 1929-1939.Publicad

Medio siglo de desigualdad en el ingreso en México

ResumenEste trabajo muestra la evolución de la desigualdad en la distribución del ingreso en México entre los años 1963 y 2010. Identifica tres fases: la primera registra una caída lenta pero tendencial de la desigualdad que culmina con la medición de 1984. La segunda, donde la desigualdad se eleva y se mantiene alta, se extiende desde 1989 hasta el año 2000; en este período tiene lugar el cambio en la orientación del modelo económico. La tercera fase muestra una disminución de la desigualdad a un escalón inferior en relación a la segunda e inicia en 2002, año de plena retracción económica que se caracteriza por una serie de modificaciones en la política social. En este artículo se argumenta que no hay suficiente información empírica para sustentar que hay una tendencia hacia la reducción de la desigualdad, sólo permite diferenciar escalones; y que la distribución del ingreso en 2010 es muy similar a la de 1984. Tomó un poco más de un cuarto de siglo para que México volviera a tener la distribución del ingreso que había alcanzado en la época del desarrollo orientado hacia adentro.AbstractThis work shows the evolution of inequality of the distribution of income in Mexico between 1963 and 2010. It identifies 3 stages: The first, which coincides with the abandonment of the stabilizing development model, register a slow but leaning drop of the inequality, finishing with 1984’s evaluation. The second, where inequality rises and stays high, lasts from 1989 to 2000. During this time, a change takes place in the direction of the economic model. The third began in 2002, a year of full economic shrinking. It was characterized by a series of changes in social policy, and shows a decrease in inequality to a lower level in relation to the second stage (% the most important factors to consider are the …% adoption of conditional financial transfer programs, which has caused trade liberalization in the agricultural sector; and public expenditure policy to face up to the crisis that the Mexican government has had in the last years). The author argues that there is not enough empirical information to support that there exist a (linear) tendency towards a reduction in inequality. And, that the income distribution in 2010 is very similar to that of 1984. It took a little over a quarter century for Mexico to achieve a comparable income distribution that it had at the inward-oriented development time

The party politics of Euroscepticism in times of crisis: the case of Greece

This article traces the trajectory of party Euroscepticism in Greece drawing upon theories of issue competition. It demonstrates that the economic dimension of the multiple crises facing the EU contributed to a Eurosceptic shift in public opinion; the electoral success of Eurosceptic parties; new parties populating the Europhile end of the spectrum; and the formation of a coalition government united not by ideological affinity but by a common Eurosceptic and anti-austerity agenda. Mainstream parties maintained their pro-EU agendas and challenger parties offered both pro- and anti-EU policy options to the electorate. The prospect of power resulted in the progressive softening of Euroscepticism among challenger parties. EU issue salience was relatively high across the party system and remained so during the crisis. Although Greek parties justified their pro- and anti-EU attitudes using a number of frames, economic arguments were prevalent at the height of the crisis, and challenger parties of the left intensified their claims of the EU interfering in national politics. The findings have implications for our understanding of the evolving nature of Euroscepticism and the ways in which it may feature in domestic party politics

Evolución y características de la pobreza en México en la última década del siglo XX

Durante la década de los noventa, México sufrió una serie de transformaciones profundas en varios ámbitos. Por una parte, se afianzó la apertura comercial y el país entró en un acelerado proceso de integración a los mercados mundiales y de cambio en sus estructuras productivas. Por la otra, se aceleró el proceso de democratización del país y, después de siete décadas en el poder, el partido político que había mantenido su hegemonía perdió las elecciones presidenciales. ¿Cómo cambió el nivel de vida de la población durante este período? Así como han estado en marcha los procesos de transición económica y política, ¿puede hablarse ya del inicio de una transición social hacia una sociedad más justa? El presente artículo examina precisamente la evolución de la pobreza en México durante los años noventa.desarrollo social, mexico, pobreza, apertura comercial