scholarly journals Pengaruh Suhu Dan Waktu Tinggal Terhadap Kecenderungan Menguning Pada Proses Produksi Alumunium Fasad

Author(s):  
Sukram Sukram ◽  
Sutikno Sutikno

Painting using paint powder is one of the techniques of protection against corrosion are evolving rapidly. Powder paints have aesthetic value approaching liquid paint as well as durability and relative utilization is better than liquid paint. The process of maturation of the paint powder that is only done with the process of warming at a certain temperature and a certain span of time. Standard maturation process known as maturation curve (curing folder). The difference in temperature and time against standard value ranges of risk occurrence of color change especially in white color (light). Therefore, do the research to find out the influence of temperature and time of warming up against the tendency of yellowing in white powder paint. Colour measurement is performed using a colorimeter in units of CIE Lab. Value b in CIE lab color trend show the yellowish or bluish. Temperature and time of warming up is the variable factor research determined 5.Keyword : paint powder, maturation, temperature, color. Pengecatan menggunakan cat bubuk merupakan salah satu teknik perlindungan terhadap korosi yang berkembang secara pesat. Cat bubuk memiliki nilai estetika mendekati cat cair serta daya tahan dan utilisasi yang relative lebih baik dibanding cat cair. Proses pematangan cat bubuk yang hanya dilakukan dengan proses pemanasan pada suhu tertentu dan rentang waktu tertentu. Standard proses pematangan dikenal dengan kurva pematangan (curing map). Perbedaan suhu dan waktu terhadap rentang nilai standard menimbulkan resiko terjadinya perubahan warna khususnya pada warna putih (terang). Oleh sebab itu dilakukan penelitian untuk mengetahui pengaruh suhu dan waktu pemanasan terhadap kecenderungan menguning pada cat bubuk warna putih. Pengukuran warna dilakukan dengan menggunakan colorimeter dalam satuan CIE Lab. Nilai b  pada CIE lab menunjukan kecenderungan warna kekuningan atau kebiruan. Suhu dan waktu pemanasan merupakan variabel penelitian yang faktornya ditentukan 5⁰C dan 5 menit diluar kurva pematangan. Kata kunci: cat bubuk, pematangan, suhu, warna.

Author(s):  
John P. Langmore ◽  
Brian D. Athey

Although electron diffraction indicates better than 0.3nm preservation of biological structure in vitreous ice, the imaging of molecules in ice is limited by low contrast. Thus, low-dose images of frozen-hydrated molecules have significantly more noise than images of air-dried or negatively-stained molecules. We have addressed the question of the origins of this loss of contrast. One unavoidable effect is the reduction in scattering contrast between a molecule and the background. In effect, the difference in scattering power between a molecule and its background is 2-5 times less in a layer of ice than in vacuum or negative stain. A second, previously unrecognized, effect is the large, incoherent background of inelastic scattering from the ice. This background reduces both scattering and phase contrast by an additional factor of about 3, as shown in this paper. We have used energy filtration on the Zeiss EM902 in order to eliminate this second effect, and also increase scattering contrast in bright-field and dark-field.


2018 ◽  
Vol 2 (5) ◽  
pp. 744
Author(s):  
Zainur Zainur

This research was motivated by the low learning outcomes of grade IX SMP Muhammadiyah Padang LuasKecamatan Tambang Kabupaten Kampar. This study aims to improve learning outcomes in mathematicslearning through STAD type cooperative learning with the RME approach in class IX SMP MuhammadiyahPadang Luas Kecamatan Tambang Kabupaten Kampar. The subjects of this study were all classes IX in SMPMuhammadiyah Padang Luas Kecamatan Tambang Kabupaten Kampar totaling 26 people. The form ofresearch is classroom action research. This research instrument consists of performance instruments and datacollection instruments in the form of teacher activity observation sheets and activities. The results of the studystated that there were significant differences between students' mathematics learning outcomes before applyingthe STAD type cooperative learning model with the RME approach with after applying the STAD typecooperative learning model with the RME approach. The difference shows student learning outcomes after theaction is better than before the action with completeness reaching 80.77% or 21 completed. Based on the resultsof the study and discussion it can be concluded that the application of STAD type learning model with RealisticMathematic Education (RME) approach can improve the learning outcomes of grade IX students of SMPMuhammadiyah Padang Luas Kecamatan Tambang Kabupaten Kampar on statistical material.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
R Bosco ◽  
S Gambelli ◽  
V Urbano ◽  
G Cevenini ◽  
G Messina

Abstract Background Sanitizing the operating theatres (OT) is important to minimize risk of post-operative infections. Disinfection procedures between one operation and another is less aggressive than final cleaning procedures, at the end of the day. Aim was assessing the difference of contamination: i) between different levels of disinfection; ii) before and after the use of a UVC Device (UVC-D). Methods Between December 2019/February 2020 a cross sectional study was conducted in OT in a real clinical context. 94 Petri dishes (PD) were used in 3 OT. Three different sanitation levels (SL1-3) were compared pre- and post-use of UVC-D: i) No cleaning after surgery (SL1); ii) after in-between cleaning (SL2); iii) after terminal cleaning (SL3). UVC-D was employed for 6 minutes, 3 minutes per bed side. PD were incubated at 36 °C and colony forming unit (CFU) counted at 48h. Descriptive statistic, Wilcoxon and Mann-Whitney tests were performed to assess the contamination levels in total, pre/post use of UVC-D, and between different sanitation levels, respectively. Results In total we had a mean of 3.39 CFU/PD (C.I. 2.05 - 4.74) and a median of 1 CFU/PD (Min. 0 - Max. 39), after UVC-D use we had a mean of 2.20 CFU/PD (C.I. 0.69 - 5.09) and a median of 0 CFU/PD (Min. 0 - Max. 133). The UVC-D led to a significant reduction of CFU (p < 0.001). Without UVC-D we had a significant CFU drop (p < 0.05) between SL1 and SL3. Using UVC-D, we observed significant reductions of contamination (p < 0.05) between SL3 and SL1. Comparing SL1 (median 0) post UVC-D use vs SL2 pre UVC-D use (median 0.5), and SL2 post UVC-D use (median 0) vs SL3 pre UVC-D use (median 1) we had a significant reduction of contamination (p < 0.05). Conclusions UVC-D improved environmental contamination in any of the three sanitation levels. Furthermore, the use of UVC-D alone was better than in-between and terminal cleaning. Although these encouraging results, the cleaning procedures executed by dedicated staff has to be considered. Key messages UVC are efficient to decrease contamination in operating theatres regardless of sanitation levels. The additional use of UVC technology to standard cleaning procedures significantly improves sanitation levels.


2007 ◽  
Vol 330-332 ◽  
pp. 495-498
Author(s):  
Chao Zou ◽  
Wen Jian Weng ◽  
Xu Liang Deng ◽  
Kui Cheng ◽  
Pi Yi Du ◽  
...  

Two starting collagens, sponge and floc collagen, were used to prepare collagen/tricalcium phosphate (TCP) composites. The resulting composites were porous and had 200μm pore size. However, there was a difference in the microstructure of the pore walls for the composites derived from the two collagens, the pore walls in sponge collagen/TCP composite were still porous and had 200 nm micropores size, TCP particles were trapped in collagen matrices. While floc collagen/TCP composite had smooth and dense walls in which TCP particles were embedded. The difference could be attributed to the starting collagen with different status. Sponge collagen has a soft structure, which easily becomes disassembled fibrils during alkali treatment, the disassembled fibrils are integrated again to form a dense morphology for pore walls after freeze-drying. While floc collagen has already a low disassembly degree, the alkali treatment could not be able to separate the fibrils, this remains as micropores in pore walls after freeze-drying. Both porous composites are significant in bone tissue engineering or regeneration. MTT test results showed the two composites had good cytocompatibility, and sponge collagen/TCP composite was somewhat better than floc collagen/TCP composite, which could result from that micropores derived roughness in pore walls of sponge collagen/TCP composite is suitable for cell growth.


1988 ◽  
Vol 55 (4) ◽  
pp. 579-583 ◽  
Author(s):  
Lucas Dominguez ◽  
José Francisco Fernández ◽  
Victor Briones ◽  
José Luis Blanco ◽  
Guillermo Suárez

SummaryDifferent selective agar media were compared for the recovery and isolation of five species ofListeriafrom raw milk and cheese. The selective media examined were Beerens medium, MacBride medium and that described by Dominguezet al.(1984) with 6 mg/1 acriflavine, listeria selective agar medium (LSAM), and LSAM with 12 mg/1 acriflavine (LSAM × 2A); a non-selective yeast glucose Lemco agar was included for comparison. When the difference between listeria and the natural microflora of raw milk and cheese was 102cfu/ml, listeria could be isolated by direct plating on all media tested. When it was lower than 103–104cfu/ml, listeria were isolated by direct plating only on LSAM and LSAM × 2A. When the difference was greater than 104cfu/ml, a previous enrichment was necessary to isolate them. LSAM and LSAM × 2A media performed better than the other media tested for isolating listeria by direct plating and improved their isolation from dairy products. This superior performance was evaluated by the ability of these media to support colony formation of different species ofListeriatested, the easy recognition of these colonies from those formed by other microorganisms and by their capacity to inhibit the natural microflora of these foods.


De Jure ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Daniel Haman ◽  
◽  
◽  

The difference between intent (dolus) and negligence (culpa) was rarely emphasized in codified medieval laws and regulations. When compared to the legal statements related to intent, negligence was mentioned even more rarely. However, there are some laws that distinguished between the two concepts in terms of some specific crimes, such as arson. This paper draws attention to three medieval Slavic legal documents – the Zakon Sudnyj LJudem (ZSLJ), the Vinodol Law and the Statute of Senj. They are compared with reference to regulations regarding arson, with the focus being on arson as a crime committed intentionally or out of negligence. The ZSLJ as the oldest known Slavic law in the world shows some similarities with other medieval Slavic legal codes, especially in the field of criminal law, since most of the ZSLJ’s articles are related to criminal law. On the other hand, the Vinodol Law is the oldest preserved Croatian law and it is among the oldest Slavic codes in the world. It was written in 1288 in the Croatian Glagolitic script and in the Croatian Chakavian dialect. The third document – the Statute of Senj – regulated legal matters in the Croatian littoral town of Senj. It was written in 1388 – exactly a century after the Vinodol Law was proclaimed. When comparing the Vinodol Law and the Statute of Senj with the Zakon Sudnyj LJudem, there are clear differences and similarities, particularly in the field of criminal law. Within the framework of criminal offenses, the act of arson is important for making a distinction between intent and negligence. While the ZSLJ regulates different levels of guilt, the Vinodol Law makes no difference between dolus and culpa. On the other hand, the Statute of Senj strictly refers to negligence as a punishable crime. Even though the ZSLJ is almost half a millennium older than the Statute of Senj and around 400 years older than the Vinodol Law, this paper proves that the ZSLJ defines the guilt and the punishment for arson much better than the other two laws.


1971 ◽  
Vol 36 (2) ◽  
pp. 208-212 ◽  
Author(s):  
Herbert J. Arkebauer ◽  
George T. Mencher ◽  
Carol McCall

Ten patients with bilateral asymmetrical hearing losses were tested for differences in speech discrimination scores under the following listening conditions: poorer ear under earphone; better ear under earphone; sound field, ears unoccluded; and sound field, poorer ear occluded. A patient manifesting a bilateral asymmetrical hearing loss may not be able to either separate or integrate two speech signals; however, occlusion of the poorer ear may be an advantageous means of obtaining maximum speech discrimination. Examination of the speech discrimination scores indicates the existence of detrimental interaction between ears exhibiting bilateral asymmetrical hearing loss. These findings also indicate that when the difference between ears is greater, speech discrimination is better than when asymmetry approximates symmetry. Apparently, the greater the impairment in the better ear, the greater the results to be gained by occluding the poorer ear. These findings were interpreted as being relevant in determining candidacy for binaural amplification. Such candidacy should be determined on the basis of speech discrimination scores obtained from each ear independently, and the combined effect of both aids.


1977 ◽  
Vol 57 (2) ◽  
pp. 365-374 ◽  
Author(s):  
I. R. SIBBALD ◽  
K. PRICE

Thirty samples of wheat and 28 samples of oats were assayed for true and apparent metabolizable energy (TME, AME). Within grains, the difference TME−AME increased with decreasing AME values; there is evidence that this trend is associated with reduced voluntary consumption of AME assay diets containing low energy grains. The TME and AME data were compared with ME values predicted from physical and chemical data describing the grains. Previously published prediction equations were tested and new equations were derived. Comparisons between predicted and observed data suggested that both the TME and AME values of wheat were predicted with insufficient accuracy and precision for practical use. Similar comparisons using the oat data showed high correlations between observed and predicted values, although the predictions were no more accurate than for wheat; however, when data describing four samples of naked oats were removed, the correlations were reduced substantially. Comparisons involving data for the hulled oats indicated that most equations were able to predict AME better than TME. Multiple regression analysis was used to identify those combinations of variables best able to predict TME data. No combination of variables was best for both wheat and oats. The combinations of variables used in published equations performed quite well. With four variables, the percentage of the TME variation explained was as high as 52 for wheat, 82 for oats and 64 for hulled oats. Predictions based on air-dry data are associated with higher correlations than those based on dry matter data, but the air-dry predictions are the less useful in practice. The reason for this is discussed.


1984 ◽  
Vol 64 (2) ◽  
pp. 253-265 ◽  
Author(s):  
SARAH BUTSON ◽  
R. T. BERG

A milking experiment with range, single-suckled beef cows was conducted over two lactations in 1976 and 1977 at the University of Alberta Research Ranch. A total of 428 cows were milked, ranging from 2 to 10 yr of age and representing four breed groups of Herefords and crossbreds of traditional beef and dairy breeds. Measurements of milk were taken in June and September each year. Milk was extracted following an intrajugular injection of 20 IU of oxytocin. Samples were analyzed for butterfat percent, protein percent and lactose percent. Age and breed of dam differences in milk yields, constituent percentages and yields were assessed. Least squares means of yields pooled over the two periods each year indicated that dams with Holstein and Brown Swiss breeding (DS) yielded more milk than beef crossbreds and purebred Herefords. Average milk yields estimated over 24 h ranged from 5.7 kg/day for Herefords to 7.8 kg/day for DS dams. Compared to 2-yr olds at 100%, 3-yr olds produced 125%, 4-yr olds 136% and mature cows 139% greater yield. The difference between June and September yields was evident between breed groups. Hereford milk production exhibited the greatest decline over 87 days compared to all other crossbreds and DS were the most persistent. Mature cows maintained milk yields better than younger cows, and 2-yr old milk yields declined most noticeably. All crossbred groups produced less butterfat percent and lactose percent content than the Herefords, yet yielded more total energy. All constituent percentages were higher than those reported for commercial dairy cattle. All constituent percentages increased significantly from June to September at approximately 130 days in lactation. A significant decline was noted for all constituent yields in September. Dairy crossbreds demonstrated the highest persistency for all constituent yields. Beef Synthetic dams were intermediate in yield persistency. Average milk yields had negative (P < 0.05) correlations with average constituent percentages. Inter-correlations among constituent percentages were variable and generally small and negative. Key words: Lactation, range cows


Solid Earth ◽  
2016 ◽  
Vol 7 (4) ◽  
pp. 1157-1169 ◽  
Author(s):  
Paul W. J. Glover

Abstract. When scientists apply Archie's first law they often include an extra parameter a, which was introduced about 10 years after the equation's first publication by Winsauer et al. (1952), and which is sometimes called the “tortuosity” or “lithology” parameter. This parameter is not, however, theoretically justified. Paradoxically, the Winsauer et al. (1952) form of Archie's law often performs better than the original, more theoretically correct version. The difference in the cementation exponent calculated from these two forms of Archie's law is important, and can lead to a misestimation of reserves by at least 20 % for typical reservoir parameter values. We have examined the apparent paradox, and conclude that while the theoretical form of the law is correct, the data that we have been analysing with Archie's law have been in error. There are at least three types of systematic error that are present in most measurements: (i) a porosity error, (ii) a pore fluid salinity error, and (iii) a temperature error. Each of these systematic errors is sufficient to ensure that a non-unity value of the parameter a is required in order to fit the electrical data well. Fortunately, the inclusion of this parameter in the fit has compensated for the presence of the systematic errors in the electrical and porosity data, leading to a value of cementation exponent that is correct. The exceptions are those cementation exponents that have been calculated for individual core plugs. We make a number of recommendations for reducing the systematic errors that contribute to the problem and suggest that the value of the parameter a may now be used as an indication of data quality.


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