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The competitive adsorption of poly(ethylene glycol) (PEG) and poly(vinyl alcohol) (PVOH) onto Na-bentonite has been assessed quantitatively. Particular emphasis was focused on the amount of organic located within the bentonite interlayer and any subsequent effects on the extent of layer expansion. The individual isotherms showed strong adsorption for both PVOH and PEG at amounts lower than the quantities required to produce fully loaded bilayer (0.33 g of PVOH/g of clay) and single layered structures (0.10 g of PEG/g of clay), respectively. Above these concentrations the incremental amounts adsorbed were smaller, and the concentration of adsorbates in solution gradually increased. Na-bentonite adsorbed more PVOH than PEG at any given concentration. In the competitive study the amount of PVOH adsorbed was enhanced in the presence of PEG (0.10 and 0.30 g/g clay), but less PEG was adsorbed. At low loadings of PVOH (0.02-0.10 g/g clay) the amount of adsorbed PEG was increased but at higher PVOH levels PEG adsorption was reduced. The XRD data showed stepped changes in the d-spacing as the adsorbed amounts of both PEG and PVOH increased. The PEG-bentonite samples did not expand beyond a bilayer structure (18 Å), but the XRD data for PVOH-treated samples indicated the formation of multilayer structures (d ≥ 44 Å).

AbstrakTujuan dan target khusus dalam penelitian ini adalah : Ingin mengetahui kandungan logam berat Tembaga (Cu) pada Bandeng (Chanos chanos Forsk) yang berasal dari Kampung Melayu Kota Bima. Manfaat khusus adalah untuk melindungi konsumen yang mengkonsumsi bandeng dari kontaminan logam berat. Penelitian dilakukan di Kampung Melayu Kota Bima yaitu pada daerah yang ada tambak bandeng. Metode Pengumpulan data dilakukan dengan menggunakan jaring insang (gill net). Sampel Bandeng diambil 3 ekor langsung pada areal tambak. Selanjutnya sampel dimasukkan ke dalam kantong plastik dan kemudian disimpan dalam kotak sampel. Sampel penelitian kemudian dianalisis di laboratorium analitik UNRAM. Metode analisis data dilakukan dengan mengambil jaringan otot dari Bandeng (Chanos chanos Forsk), kemudian dianalisis kandungan logam berat Tembaga (Cu) dengan menggunakan alat Spektrofotometer Serapan Atom (Atomic Absorption Spectrophotometer),  Pengukuran logam berat pada jaringan otot Bandeng dilakukan dengan menambahkan HNO3 pekat dan HClO4, dipanaskan pada suhu 60-70ºC selama 2-3 jam sampai larutan jernih.  Sampel siap diukur dengan AAS menggunakan nyala udara-asetilen. Hasil penelitian menemukan 27,3 % Tembaga (Cu) dalam jaringan Bandeng, yang menunjukan bahwa lingkungan tempat ikan dipelihara sudah terkontaminasi oleh Tembaga (Cu). Apabila manusia mengkonsumsi ikan bandeng yang mengandung Tembaga (Cu), maka tembaga tersebut dapat terakulumasi dalam tubuh, sehingga dapat memberikan dampak negatife bagi kesehatan.Kata kunci : Tembaga (Cu), Bandeng, dan Kampung Melayu

This study focuses on the Interpersonal Communication of Children of Indonesian Workers with Their Parents. This study is motivated by the reality of communication problems experienced by children whose parents work as Indonesian workers abroad. The relationship between children and parents is then bridged by the presence of communication technology media such as cellular phones and social media. The purpose of this study was to determine 1) Barriers to interpersonal communication between children and parents; 2) Form of parental attention to children; 3) Interpersonal Communication Process of Children and Parents. This study uses the findings of this study to indicate that First: The weakness of interpersonal communication between children and their parents is due to communication technology connections that are often cut off as well as their parents' busyness so that the network can communicate with children. Another obstacle is the lack of interpersonal meaning due to gestures and expressions that are not recognized because of indirect communication; Second: Parents pay attention to the condition of the child, but not in detail so that violations are often committed by children; Third: The form of the message in the form of closed questions causes a lack of feedback which reduces the dynamics of the conversation between parents and children.