Judul: Pengaruh kualitas air sungai gajah wong terhadap kesehatan satwa di kebun binatang gembira loka dan masyarakat sekitarnya
Abstrak: Kebun Binatang Gembira Loka memiliki peran yang besar bagi masyarakat Yogyakarta, yaitu sebagai sarana konservasi, pendidikan, penelitian, dan rekreasi. Dalam perkem bangannya, peranan Kebun Binatang Gembira Loka tersebut semakin besar, seiring dengan peningkatan kebutuhan masyarakat pada keberadaan Kebun Binatang tersebut. Karena peranannya semakin besar, maka pengelolaan Kebun Binatang Gembira Loka sangat menentukan kelangsungan fungsi atau peranan Kebun Binatang tersebut. Pengelolaan Kebun Binatang tersebut tidak lepas dari interaksi dengan sumberdaya dan lingkungan sekitarnya. Salah satu sumberdaya yang tidak dapat dipisahkan dengan pengelolaan Kebun Binatang Gembira Loka adalah keberadaan Sungai Gajah Wong. Air Sungai Gajah Wong dimanfaatkan sebagai sumber air minum bagi sebagian besar satwa di Kebun Binatang. Sebaliknya, limbah cair Kebun Binatang juga disalurkan ke perairan Sungai Gajah Wong. ...
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Judul: Manajemen Limbah Cair Buangan Kebun Binatang Gembira Loka dan Dampaknya terhadap Kualitas Air Sungai Gajahwong
Abstrak: Gembira Loka zoo produce liquid waste into Gajahwong river wasted and cause the possibility of lowering the water quality in Gajahwong river. The research was carried out in 3 point located in Gajahwong river and 1 point liquid waste disposal point Gembira Loka zoo in May-June of 2013. Analysis liquid waste based on the Governor of DIY number 7 of 2010, while water quality of the Gajahwong river uses water quality index (IKA) with 9 test parameters, BOD, DO, TDS, temperature, pH, nitrates, phosphates, fecal coliform and turbidity. Water quality include the categories medium, and there are a few parameters that exceeded the Agency's water quality standard class 2. Water quality degradation was allegedly derived from various sources pollutant. Contribution Gembira Loka zoo doesn't give significant effects in the water quality of river because of the experience dissolving organic in river, as well as supported by the results of the test liquid waste under the raw quality.
Keyword: water quality., water quality index, pollutant, liquid waste

Judul: Characterizations of low alloy steel sae 4422  plated with chromic acid (Cro3)
Abstrak: Characterizations of low alloy steel SAE 4422 plated with chromic acid (CrOrO3) was use Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), RD),Energy Dispersive Analysis of X-Ray (EDAX), Hardness Test and Roughness Test. Microstructures analysis exhibits cracks and grain boundaries microcracks as a characteristics of chrome metal found at plating metal. Perlite and Ferrite as grains of steel found at base metal with grain boundaries around it. Phase analysis of plating metal appropriate to chrome metal with lattice constant (a) is 2.559 Å and phase analysis of base metal appropriate to iron ferrite with lattice constant (a) is 3.318 Å. Both plating and base metal have cubic system. Chemical analysis of plating metal at surface section exhibits that cracks area have highest value of carbon element compare with grains and grains boundaries area. While chemical analysis of base metal at cross section exhibits that perlite have highest value of carbon element compare with ferrite and grain boundaries. The hardness value of plating metal at surface section and cross section are 753 and 637 VHN. While, the hardness value of base metal and interface area at cross section are 205 and 373 VHN. The roughness value at measurement points of chrome surface for as received sample are 0.445 μm. Observation used Optical Microscopy and Scanning Electron Microscopy exhibits surface irregularities combine to form surface texture of plating metal at surface section.
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