ESTERIFIKASI ASAM HUMAT DARI GAMBUT KALIMANTAN TENGAH UNTUK ADSORPSI ION EMAS

Produksi emas di Indonesia dalam sektor pertambangan yaitu 13,16 juta ton/tahun dengan potensi sumber dayanya yang mencapai 14.900 juta ton dan cadangan sebesar 3.600 juta ton. Pengaplikasian emas secara luas dalam berbagai bidang yaitu kecantikan, Kesehatan dan perhiasan menyebabkan meningkatnya upaya perolehan emas. Metode alternatif yang dapat digunakan untuk memperoleh logam emas yaitu dengan proses adsorpsi dengan material asam humat dari gambut.Kalimantan Tengah. Tujuan penelitian ini yaitu memodifikasi asam humat dari gambut Kalimantan Tengah dengan proses esterifikasi untuk adsorpsi emas. Modifikasi dilakukan dengan menggunakan etanol sebagai pereaksi dan H2SO4 sebagai katalis. Uji kemampuan adsorpsi dilakukan dengan variasi pH yaitu 1, 2, 3, 4 dan 5, kemudian dilanjutkan dengan melakukan variasi konsentrasi yaitu 10, 15, 20, 25, 30 dan 50 ppm. Hasil karakterisasi adsorben emas berbahan dasar asam humat dari gambut menggunakan XRD menunjukkan struktur amorf. Pola serapan FTIR menunjukkan adanya vibrasi gugus O-H, C-H alifatik, deformasi C-H, C=O dan C-O, serta adanya pergeseran serapan pada bilangan gelombang 1704 – 1712 cm-1 yang menunjukkan vibrasi ikatan C=O dari -COOR untuk sampel asam humat teresterifikasi sebagai indikasi keberhasilan proses esterifikasi. Proses adsorpsi AuCl4- oleh adsorben AHE1 secara optimal terjadi pada pH 2 dengan persentase removal 69% pada konsentrasi AuCl4- 50 ppm

Can filesharers be triggered by economic incentives? Results of an experiment

Illegal filesharing on the internet leads to considerable financial losses for artists and copyright owners as well as producers and sellers of music. Thus far, measures to contain this phenomenon have been rather restrictive. However, there are still a considerable number of illegal systems, and users are able to decide quite freely between legal and illegal downloads because the latter are still difficult to sanction. Recent economic approaches account for the improved bargaining position of users. They are based on the idea of revenue-splitting between professional sellers and peers. In order to test such an innovative business model, the study reported in this article carried out an experiment with 100 undergraduate students, forming five small peer-to-peer networks.The networks were confronted with different economic conditions.The results indicate that even experienced filesharers hold favourable attitudes towards revenue-splitting.They seem to be willing to adjust their behaviour to different economic conditions

Chemical characteristic of Fly ash and Bottom ash as potential source for synthesis of Aluminosilicate-based materials

The world's population has reached 7 billion or doubled from the previous half-century and continues to increase every year. This increase in population is directly proportional to the increase in electrical energy consumption. Electricity needs in Indonesia are mostly met by Steam Power Plants. Unfortunately, the use of coal as an energy source in Steam Power Plants can cause environmental pollution, namely the waste generated by fly ash and bottom ash. However, even though it is classified as hazardous materials, silica (SiO2) and alumina (Al2O3) content in the waste are high enough so that it can be used for the synthesis of aluminosilicate-based materials. The ash waste in this study was obtained from the Steam Power Plant in Kapuas Regency, Central Kalimantan Province which was tested according to the ASTM D93-10 standard. The composition of SiO2, Al2O3, Fe2O3, and CaO in fly ash was 56.44; 31.31; 0.51; 0.78%. The compositions of SiO2, Al2O3, Fe2O3 and CaO in the bottom ash were 66.66; 17.09; 0.31; 5.40%. Based on its composition, fly ash and bottom ash are classified as type F ash. In addition, fly ash and bottom ash have SiO2/Al2O3 ratios of 3.90 and 1.80, respectively. It can be concluded that fly ash and bottom ash has the potential to be used as basic materials for the manufacture of aluminosilicate-based materials such as geopolymers, zeolites, and others

Índice para pneumonia em granjas comerciais de suínos do estado de Pernambuco

A avaliação do estado patológico do suíno, em abatedouro, fornece dados importantes com ampla aplicação em diversos pontos do manejo sanitário. Nesta pesquisa, o índice para pneumonia (IPP) foi utilizado para investigar 32 granjas de suínos destinadas à produção comercial no Estado de Pernambuco. Dos 436 pulmões analisados 284 (65,13%) apresentaram lesões e os valores do IPP variaram de 0,50 a ?1,0. Esses resultados refletem a importância de avaliar o manejo sanitário e implantar um efetivo programa de controle para a pneumonia suín

A Review: Development of Photocatalyst Materials and Its Performance for Humic Acid Removal in Peatwater

Peat is a wetland region in Indonesia with a very high water storage capacity. However, the amount of humic compounds obtained from the accumulation of organic substances in peat makes the water unable to be used for daily purposes. Peat water treatment with several methods has been carried out, such as coagulation, electrocoagulation, flocculation, and filtration. However, the result of clumping or filtering in such a way raises new environmental problems. One method which effective and efficient used in peat water treatment is photocatalytic. Several materials based-semiconductor was developed as a photocatalyst, another modification of photocatalyst is combining the adsorbent as a porous supporting photocatalyst which can improve its performance

Why do people file share unlawfully? A systematic review, meta-analysis and panel study

Unlawful digital media sharing is common and believed to be extremely damaging to business. Understanding unlawful file sharers’ motivations offers the opportunity to develop business models and behavioral interventions to maximize consumers’ and businesses’ benefit. This paper uses a systematic review of unlawful file sharing research, and the Theory of Planned Behavior, to motivate a large-scale panel study in which initial determinants were used to predict subsequent behavior. A meta-analysis found Attitudes, Subjective Norms and Perceived Behavioral Control were all associated with unlawful file sharing. Media type and demographic differences in the importance of Perceived Behavioral Control were found and attributed to more accurate evaluation of familiar activities, i.e., greater experience increases the influence of Perceived Behavioral Control but age does not. The panel study confirmed that greater past experience was associated with Perceived Behavioral Control and Intention. We conclude that past experience increases the efficacy of the Theory of Planned Behavior and specifically Perceived Behavioral control in predicting behavior, contrary to some widely held beliefs about the role of experience. The role of experience is therefore crucial to understanding people’s choices. Practically, improving social approval, positive evaluation and access to lawful media should reduce unlawful behavior

The hegemonic copyright-regime vs. the sharing copyright users of music?

In this commentary the increasing discrepancy between the emerging participatory networked culture and the hegemonic copyright and intellectual property regime is contextualised and subsequently problematised. While this is a feature and growing conflict for every form of authored work – news, films, books, academic work, photography, the focus here is on music and more in particular on the sharing of music. Sharing music is not a new phenomenon, but current copyright users share music with weak peers in addition to strong peers which has taken sharing to a whole different level reminiscent of a gift-culture, but with less need for reciprocity. Music audiences attribute less value to a digital product than to an artefact such as a CD or vinyl record. The reaction of the music industry to these phenomena has been hostile up until now, criminalising the copyright user and lobbying for the close monitoring of the online behaviour of all internet users. However, while the industry foregrounds its potential losses based on the number of downloads, as well as the difficulties this provokes for young beginning artists, others are pointing towards the societal benefits of worldwide free access to such a wide variety of music. Furthermore, several counter-voices in the copyright debate have emerged, from copyleft to copyriot and more and more artists mainstream and alternative are engaging fully with the participatory culture. In this commentary an argument is developed in favour of the music industry embracing this participatory networked culture rather than take us back to the future of 1984. Democracy and civic liberties are more important than the corporate interests of a few

Copyright infringement online: the case of the Digital Economy Act judicial review in the United Kingdom

The proportionality of the UK Digital Economy Act 2010 which aims to curtail illegal peer-to-peer file-sharing is examined in this paper in the light of changes in online norms and culture. Based on an analysis of recent studies and a critical reflection on the nature of changes in digital media production and file-sharing behaviour, we conclude that the Digital Economy Act introduces disproportionate social costs for UK Internet users, with uncertain prospects for improving creative industry revenues. The wider implications of these developments for the emerging online culture are also considered