Jurnal Teknosains
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Rasio natrium karbonat dalam ekstraksi berpengaruh pada mutu natrium alginat sargassum muticum
No full textBrown seaweed is one of Indonesia’s biological resources which has good potential as source for alginate which can be used for the food and non-food industries. Alginate was most widely used in the textile sector around 50%, food industry 30%, paper industry 6%, welding rods 5%, pharmacy 5% and other 4%. The process of taking alginate from brown seaweed can be done by extraction. Several studies have been carried out in an effort to improve the yield of alginate extraction. The objective of this study was to determine the effect of the ratio of Na2CO3 and obtain the best ratio of Na2CO3 for producing sodium alginate from Sargassum muticum. The ratio of Na2CO3 used was 1:10, 1:20, 1:30, 1:40, 1:50 (w/v) and observations of alginate quality included yield (%), viscosity (cps), pH, water content (%), whiteness degree (%), ash content (%) and functional groups. The results showed that the higher the ratio of Na2CO3 produced the lower viscosity and showed significantly different values but yield, pH, water content, whiteness degree, and ash content were not significantly different. The functional groups at the ratio 1:20, 1:30, and 1:40 (w/v) showed the alginate that were in accordance with the standard. The best ratio of Na2CO3 from this study was 1:20 (w/v) because it had a medium viscosity, besides that, the yield, pH, water content, whiteness degree, and ash content also accordance to the quality of alginate standard
Pementaan dan faktor risiko sosioekonomi dan perilaku terhadap kejadian penyakit periodontal di kecamatan pundong kabupaten bantul
No full textPeriodontal disease is pathological damage that affects the tooth supporting tissues. Systemic conditions largely influence its pathogenesis. Besides, environmental, socioeconomic, behavioural, environmental and geographic factors can affect individuals experiencing periodontal disease. Geographic Information System (GIS) can be used to analyze the differences of these factors, especially those relating to geographic differences, demographic factors, social, etc. Pundong district has geographical and socio-economic variation. This study aims to describe the distribution of patients with periodontal disease based on socioeconomic and behavioral factors. The type of study was an observational analytic survey with a cross-sectional design. The subject of research is determined by Registry Based Study approach where Pundong Community Health Center as the primary data source in this research. Independent variable is periodontal disease, while the dependent variable is a socioeconomic factor and health behaviour. Overview of periodontal disease mapping using ArcGIS, with an overlay method or combining two layers, namely the administrative map of Pundong District and coordinates of patients with periodontal disease. Univariate and bivariate analysis using Stata to analyze the distribution and the relationship of each variable. Generalized periodontitis often occurs in Seloharjo. Seloharjo has the most deprived people in Pundong Sub-district. The variables significantly associated with periodontal disease severity were economic status and brushing behaviour (p-value <0.05)
Karakteristik temperatur fluida dingin pada grooved double pipe heat exchanger
No full textHeat exchangers have widespread applications in many industrials process. There are many kind of heat exchanger. One of the simply heat exchanger is double pipe heat exchanger. The need for lightweight and enhancing the heat transfer of heat exchanger accomodated by surface engineering. One of the surface passive technique applications is groove. Incising groove in pipe as concerned wide consideration as it need no additional power, decrease in weight of system and hence give more benefit in heat transfer. The characteristics of heat transfer in grooved double pipe heat exchanger was investigated experimentally in this article. The aim of this investigation is to reveal the phenomenon of temperature characteristics of cold fluid in the heat transfer process in the grooved double pipe heat exchanger. In this study, water are used as both hot and cold fluid with counter flow pattern, and the water flow rate equal to 15 lpm for both fluid. Grooves were incised on the annulus area in the outer wall of tube side with rectangular shape and circumferential pattern. The characteristics of groove dimension that are height of groove is 0,3 mm; distance between grooves is 8 mm; and the groove space which is as independent variables are 1 mm and 2 mm. The data from 1 mm and 2 mm grooves space were compared with no grooved double pipe heat exchanger data (smooth pipe). The hot fluid temperature is 50 ± 0,50C while the cold fluid temperature is 30 ± 0,50C. The temperature data on the inlet and outlet side of heat exchangers for smooth pipe, 1 mm and 2 mm groove space were compared to find out the characteristics of increasing cold fluid temperature. This study used the temperature rate and temperature acceleration method to compare the variables. The result shows that groove installation increases the amount of heat absorbed by cold fluid. The heat exchanger with 1 mm groove spaces, was able to absorb heat about ± 2.3 % better than heat exchanger with 2 mm groove space and 13,1 % better than heat exchanger with no groove
Ekspansi termal linier dan residu malam inlei gigi dengan komponen parafin Indonesia
No full textInlay wax is used for pattern of metallic inlays, crowns, and fixed partial dentures. Inlay wax must have a linear thermal expansion (LTE) and a residue that comply the standards. Inlay wax contains paraffin, carnauba, and beeswax. Paraffin and beeswax are produced in Indonesia. This study aims to examine the effect of the inlay wax compositions with paraffin and beeswax Indonesia on the LTE and residue properties. The research materials are paraffin (Pertamina, Balikpapan), beeswax (SEA, Yogyakarta), carnauba wax (Brataco Chemicals, Yogyakarta), and inlay wax (GC, Japan). Five inlay wax compositions are made with a ratio of paraffin, carnauba, and beeswax 60: 35: 5 (K-60), 65: 30: 5 (K-65), 70: 25: 5 (K-70), 75:20 : 5 (K-75), and 80: 15: 5 (K-80) (% w/w). The waxes were melted at 75 ± 5 oC then moulded for the TLE (267x6.35 x6.35 mm) and the residue (1 g) test specimens (n=4). The LTE and residue specimens were also made of paraffin, carnauba wax, beeswax, and commercial wax (n = 4). The LTE and residue tests were carried out based on ANSI/ADA specification No.4. Data were statistically analyzed by analysis of variance and LSD (α = 0.05). Anava test results showed that composition and temperature had a significant effect on LTE (p <0.05) and composition had a significant effect on residues (p <0.05). The LSD test results showed a significant difference in LTE of the K-75 group with other groups and the residues of the K-75 group and K-80 group with other groups (p <0.05). Inlay wax compositions with high paraffin concentrations have high LTE and residue. The value of LTE and residue of inlay wax with paraffin and beeswax from Indonesia are in accordance with the ANSI/ADA specification no. 4
EDITORIAL
No full textJurnal Teknosains terbit sebagai salah satu kepedulian dari Sekolah Pascasarjana UniversitasGadjah Mada akan pentingnya media publikasi ilmiah bagi pengembangan ilmu pengetahuan.Suatu hasil atau karya ilmiah tidak akan ada manfaatnya bagi pengembangan ilmu pengetahuanapabila tidak dipublikasikan secara luas. Pada penerbitan ini Jurnal Teknosains telah memilihdelapan naskah yang dianggap dapat mewakili pengembangan ilmu-ilmu multidisipliner dengandasar keilmuan bidang teknologi, agronomi, dan kesehatan.Mohon maaf apabila masih banyak kekurangan dalam penerbitan ini. Redaksi akan terusberbenah untuk meningkatkan kualitasnya. Partisipasi rekan-rekan sangat diharapkan untukdapat berbagi pengetahuan dengan mengirimkan naskah ilmiahnya pada Jurnal Teknosains.Teriring ucapan terimakasih kepada semua pihak yang telah meluangkan waktu, tenaga, danilmu pengetahuan serta wawasan akademik
Penerapan Metode Life-CycleCost dalam Perhitungan Evaluasi Ekonomi Jembatan untuk Penetuan Prioritas Penanganan Jembatan
No full textBridge oftentimes become a critical components of roads because it used to determine the maximum load capacity of a passing vehicle on the roads. The bridges require maintenance activity in the shape of general maintenance or periodically replacement while this is estimated in order that the bridge may continue to function properly. The economic evaluation of the Interurban Bridge Management System (IBMS) aims to determine the priority of bridge handling. One of the calculations required in NPV and IRR calculations used in priority handling is the cost of replacing the bridge. Over time, the Interurban Bridge Management System (IBMS) system must be constantly updated to continue to use in accordance with current circumstances and use new, better methods. This study uses Life-Cycle Cost (LCC) method as an alternative method to calculate the replacement cost of 5 bridges in Daerah Istimewa Yogyakarta in 2012. The IBMS method produces a priority sequence of bridge handling with Bogo bridge, Suru bridge, Winongo bridge, Kalasan B bridge and Duren bridge in sequence. The Life-Cycke Cost (LCC) method produces a priority sequence of bridge handling with Bogo bridge, Winongo bridge, Suru bridge, Kalasan B bridge and Duren bridge. The average initial cost of bridge replacement using both methods is 23.012%. The value earned using the Life-Cycle Cost method is always greater due to the addition of inspection fees, maintenance costs, and damage costs of the bridge
Stochastic frontier analysis on technical efficiency of strawberry farming in purbalingga regency Indonesia
No full textThe objective of this study is to determine technical efficiency and factors affecting technical inefficiency of strawberry farming in Purbalingga Regency. This study was conducted in Karangreja Subdistrict, Purbalingga Regency, Central Java Province. Purposive sampling method was utilized to select 100 farmers as the respondents. All of whom have been running their farm business for at least three years consecutively from 2015 to 2017. Stochastic frontier production function was applied to measure technical efficiency and factors affecting technical inefficiency. The findings show that strawberry farming in Purbalingga Regency, Central Java Province, is technically efficient with efficiency number varies between 26.50-99.40% and the average efficiency number of 77.80%. Furthermore, the results indicate that the farmers’ formal education and the number of household members significantly affect the technical efficiency of strawberry farming
Berkumur rebusan daun sirih merah (paper crocatum) konsentrasi 10% meningkatkan ph saliva pada lansia penderita diabetes melitus tpe 2
No full textDental caries is the major dental and oral health problems in Indonesia and world wide. Alteration in the saliva acidity level (pH) in the oral environment plays an important role in dental caries. Red betel leaf (piper crocatum) is a herbal plant that commonly found in Indonesia. Red betel leaf contains alkaloid, flavonoid, tannin and essential oil which have antibackterial activities. The aim of this study was to determine the acidity change (pH) of saliva in elderly people with diabetes mellitus type 2 after gargling of 10% boiled red betel leaves. The subjects of this study were 30 persons who divided randomly into two groups i.e treatment group and control group. Each group consisted of 15 persons. In the treatment group, the subjects gargled using 10% boiled red betel leaves, while in the control group the subject gargled using aquades. The saliva was collected on each time treated and followed by pH measuring. The data analysis was conducted by Independent t-test statistic (p≤0,05). The results showed that there was an effect of increasing salivary acidity (pH) of saliva after gargling boiled of red betel leaf (Piper crocatum) in elderly people with diabetes mellitus type 2. The change of acidity level (pH) of saliva was increased significantly at 5th to 15th minute from 5.33 to 6.67 after gargling boiled red betel leaves concentration of 10%. The acidity level range stated above indicates a norma
Design of ergonomic chair for grinding operation
No full textOne of essential production activities is grinding process. This process mainly involves the constant activity of eroding a surface to be smoother or more evenly, cutting a workpiece, creating profiles like angles and arches, sharpening a cutting tool, and finishing a final product. Meanwhile, there is no study evaluating the risk levels of workers working on grinding, and there is no unique chair specifically designed for the process. Therefore, this study aims to assess the risk levels of a grinding worker and to propose the design of an ergonomic chair that is adjustable, comfortable, durable, and keen to be used. The risk levels of the grinding workers were evaluated using REBA, while the ergonomic chair design was based on anthropometric data taken from 4 grinding workers in Bantul, Special Region of Yogyakarta, Indonesia. The researchers selected a buttock-popliteal length (seat depth), lower leg length (popliteal height) and hip breadth sitting as anthropometric measures to make a chair design for the grinding operations. After that, the existing adjustable chair designs were also considered and evaluated to get better adjustableergonomic chair design for the grinding operations. The results show that it is important that the stakeholders improve most of the grinding operations of the workers, especially by using an ergonomic chair design for grinding operation that is adjustable, comfortable, durable, and reliable. The chair height can be adjusted from 361-414 mm to adapt with the users, and the variation in product height aims to prevent bending on the back. Finally, the grinding chair can reduce the risk level from the high and medium level to the low-risk levels of working postures
Pengaruh campuran bahan bakar pertalite-bioetanol biji sorghum pada mesin bensin
No full textThe depletion of fossil fuels, rising of earth temperatures and declining of air quality are an unavoidable phenomenon today. This condition is a result of increased and excessive use of fossil fuels. Bioethanol fuel is one solution to reduce this problem that is sourced from renewable raw materials. Sorghum seeds are raw materials that have the potential to be made bioethanol due to they have a high carbohydrate content (70%). The test is performed the use of pertalite-bioethanol blends fuels was on a four-stroke gasoline engine without modification. The percentage of the mixture volume of fuel used is 10% bioethanol-90% pertalite (E10), 15% bioethanol-85% pertalite (E15) and 20% bioethanol-80% pertalite (E20). Engine speeds vary from 1000 to 4000 rpm, and properties of the sorghum seeds bioethanol-pertalite blends are measured and analyzed. The purpose of this study is to investigate engine performance and exhaust emissions at gasoline engine by using the sorghum seeds bioethanol-pertalite blends with different mixed ratios (E10, E15 and E20). The Engine performance includes engine torque, brake specific fuel consumption (BSFC) and thermal brake efficiency (BTE) analyzed. In addition, carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (NOx) emissions are measured as gasoline engine exhaust emissions. The results show that BSFC decreased while BTE increased for a fuel blends containing 20% bioethanol at 3500 rpm engine speed, with each maximum value of 246.93 g/kWh and 36.28%. It is also found that CO and HC emissions are lower for the sorghum seeds bioethanol-pertalite blends. Based on the research results, it can be concluded that the sorghum seeds bioethanol-pertalite blends can improve engine performance and reduce exhaust gas emissions