scholarly journals PENGGUNAAN BAHAN PEREKAT EPOXY RESIN DAN CYANOACRYLATE PADA KONSERVASI KOLEKSI FOSIL DI MUSEUM MANUSIA PURBA SANGIRAN, JAWA TENGAH

2021 ◽  
Vol 15 (1) ◽  
pp. 43-58
Author(s):  
Pratamanita Widi Rahayu ◽  
Andi Putranto

Penelitian ini merupakan kajian museologi dengan pokok bahasan konservasi koleksi museum, terutama penggunaan bahan perekat terhadap koleksi museum. Permasalahan yang dibahas adalah dampak penggunaan bahan perekat terhadap koleksi fosil di Museum Manusia Purba Sangiran. Tujuan penelitian adalah untuk memahami metode konservasi fosil serta mengetahui jenis bahan perekat yang paling baik untuk digunakan dalam kegiatan konservasi fosil. Penelitian ini bersifat deskriptif-eksploratif dan menggunakan metode penalaran induktif. Pengumpulan data dilakukan dengan cara observasi, wawancara, dan studi pustaka. Analisis data dilakukan dengan mengamati sampel yang diperoleh dengan metode purposive sampling. Hasil penelitian menunjukkan bahwa fosil yang direkatkan dengan epoksi resin mengalami perubahan warna menjadi gelap kehitaman dan terdapat endapan residu resin pada permukaan fosil. Sementara itu, terdapat residu transparan mengilap di permukaan fosil yang direkatkan dengan lem cyanoacrylate.

Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs

Gonadotroph cell adenomas of the pituitary are infrequent in human patients and are not invariably associated with altered gonadal function. To date, no animal model of this tumor type exists. Herein, we describe spontaneous gonadotroph cell adenomas in old male and female Sprague-Dawley rats by histology, immunocytology and electron microscopy.The material consisted of the pituitaries of 27 male and 38 female Sprague Dawley rats, all 26 months of age or older, removed at routine autopsy. Sections of formal in-fixed, paraffin-embedded tissue were stained with hematoxylin-phloxine-saffron (HPS), the PAS method and the Gordon-Sweet technique for the demonstration of reticulin fibers. For immunostaining, sections were exposed to anti-rat β-LH, anti-ratβ-TSH, anti-rat PRL, anti-rat GH and anti-rat ACTH 1-39. For electron microscopy, tissue was fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4 and embedded in epoxy-resin. Tissue fixed in 10% formalin, embedded in epoxy resin without osmification, was used for immunoelectron microscopy.


Author(s):  
J. Temple Black ◽  
William G. Boldosser

Ultramicrotomy produces plastic deformation in the surfaces of microtomed TEM specimens which can not generally be observed unless special preparations are made. In this study, a typical biological composite of tissue (infundibular thoracic attachment) infiltrated in the normal manner with an embedding epoxy resin (Epon 812 in a 60/40 mixture) was microtomed with glass and diamond knives, both with 45 degree body angle. Sectioning was done in Portor Blum Mt-2 and Mt-1 microtomes. Sections were collected on formvar coated grids so that both the top side and the bottom side of the sections could be examined. Sections were then placed in a vacuum evaporator and self-shadowed with carbon. Some were chromium shadowed at a 30 degree angle. The sections were then examined in a Phillips 300 TEM at 60kv.Carbon coating (C) or carbon coating with chrom shadowing (C-Ch) makes in effect, single stage replicas of the surfaces of the sections and thus allows the damage in the surfaces to be observable in the TEM. Figure 1 (see key to figures) shows the bottom side of a diamond knife section, carbon self-shadowed and chrom shadowed perpendicular to the cutting direction. Very fine knife marks and surface damage can be observed.


Author(s):  
J. G. Adams ◽  
M. M. Campbell ◽  
H. Thomas ◽  
J. J. Ghldonl

Since the introduction of epoxy resins as embedding material for electron microscopy, the list of new formulations and variations of widely accepted mixtures has grown rapidly. Described here is a resin system utilizing Maraglas 655, Dow D.E.R. 732, DDSA, and BDMA, which is a variation of the mixtures of Lockwood and Erlandson. In the development of the mixture, the Maraglas and the Dow resins were tested in 3 different volumetric proportions, 6:4, 7:3, and 8:2. Cutting qualities and characteristics of stability in the electron beam and image contrast were evaluated for these epoxy mixtures with anhydride (DDSA) to epoxy ratios of 0.4, 0.55, and 0.7. Each mixture was polymerized overnight at 60°C with 2% and 3% BDMA.Although the differences among the test resins were slight in terms of cutting ease, general tissue preservation, and stability in the beam, the 7:3 Maraglas to D.E.R. 732 ratio at an anhydride to epoxy ratio of 0.55 polymerized with 3% BDMA proved to be most consistent. The resulting plastic is relatively hard and somewhat brittle which necessitates trimming and facing the block slowly and cautiously to avoid chipping. Sections up to about 2 microns in thickness can be cut and stained with any of several light microscope stains and excellent quality light photomicrographs can be taken of such sections (Fig. 1).


Author(s):  
C. F. Oster

Although ultra-thin sectioning techniques are widely used in the biological sciences, their applications are somewhat less popular but very useful in industrial applications. This presentation will review several specific applications where ultra-thin sectioning techniques have proven invaluable.The preparation of samples for sectioning usually involves embedding in an epoxy resin. Araldite 6005 Resin and Hardener are mixed so that the hardness of the embedding medium matches that of the sample to reduce any distortion of the sample during the sectioning process. No dehydration series are needed to prepare our usual samples for embedding, but some types require hardening and staining steps. The embedded samples are sectioned with either a prototype of a Porter-Blum Microtome or an LKB Ultrotome III. Both instruments are equipped with diamond knives.In the study of photographic film, the distribution of the developed silver particles through the layer is important to the image tone and/or scattering power. Also, the morphology of the developed silver is an important factor, and cross sections will show this structure.


Author(s):  
R.L. Pinto ◽  
R.M. Woollacott

The basal body and its associated rootlet are the organelles responsible for anchoring the flagellum or cilium in the cytoplasm. Structurally, the common denominators of the basal apparatus are the basal body, a basal foot from which microtubules or microfilaments emanate, and a striated rootlet. A study of the basal apparatus from cells of the epidermis of a sponge larva was initiated to provide a comparison with similar data on adult sponges.Sexually mature colonies of Aplysillasp were collected from Keehi Lagoon Marina, Honolulu, Hawaii. Larvae were fixed in 2.5% glutaraldehyde and 0.14 M NaCl in 0.2 M Millonig’s phosphate buffer (pH 7.4). Specimens were postfixed in 1% OsO4 in 1.25% sodium bicarbonate (pH 7.2) and embedded in epoxy resin. The larva ofAplysilla sp was previously described (as Dendrilla cactus) based on live observations and SEM by Woollacott and Hadfield.


1982 ◽  
Vol 43 (C9) ◽  
pp. C9-509-C9-511
Author(s):  
P. Doussineau ◽  
W. Schön

2020 ◽  
Vol 5 (1) ◽  
pp. 52
Author(s):  
Sukirno Sukirno

Abstract This study aims to empirically challenge the moderation of Non-Performing Loans to the effect of Credit Distribution Rates on Profitability. The population of 81 bank companies listed on the Indonesia Stock Exchange in the period 2014-2018 and which met the criteria of the research sample (purposive sampling) were 22 companies. The research method uses survey methods with quantitative research approaches, the analytical tool used is moderation regression. This study concludes that the level of credit distribution has a significant positive effect on profitability and the existence of the problem loan variable is proven to be a moderating variable that weakens the relationship between the level of credit distribution and profitability.    


2020 ◽  
Vol 18 (1) ◽  
pp. 147
Author(s):  
Yuni Rachmawati ◽  
Rifani Akbar Sulbahri

Perusahaan Food and Beverage merupakan sektor yang strategis, terlihat dari peningkatan realisasi investasi terbesar dari lima sektor industri lainnya. Menjamurnya perusahaan makanan serta bangkrutnya beberapa industri makanan menjadi tantangan sekaligus ancaman bagi industri ini. Nyonya Meneer, pabrik jamu yang berjaya di masanya dinyatakan pailit pada Agustus 2017. Hal ini mendukung tujuan penelitian yaitu menganalisis kemungkinan kebangkrutan perusahaan Food and Beverage yang terdaftar di Bursa Efek Indonesia per periode 2018 menggunakan Model Springate dan Model Zmijewski. Melalui purposive sampling diperoleh tiga belas perusahaan Food and Beverage yang terdaftar di BEI periode 2018. Teknik pengumpulan data yang digunakan yaitu dokumentasi dan dianalisis dengan deskriptif kuantitatif dan kualitatif. Menurut hasil perhitungan metode Zmijewski hanya satu perusahaan yang diprediksi mengalami kebangkrutan yaitu PSDN. Sedangkan menurut model Springate terdapat 5 perusahaan yang diprediksi bangkrut yaitu ALTO, INDF, PSDN, ROTI dan SKBM. Sedangkan dari uji akurasi menunjukkan bahwa model Zmijewski memiliki tingkat akurasi lebih tinggi dibandingkan Model Springate yakni 92,3%.


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