Perhitungan Waktu Dan Biaya Pada Proses Pemesinan Benda Uji Tarik

A machine tool must be able to produce high-quality product. But a skilled operator also required. The process of workpiece production begins with planning a logical working steps, such as: specifying the type of machine tool's process and selecting the materials to be used. The production process is not only related to the technology, but also related to the cost factor and the production speed to achieve the target and optimum profits. In the tensile test, the specimen is standardized according to the tensile machine that will be used. The shape of the tested specimen is essential in order to avoid cracking or facture in the grip or others areas. The purpose of this study are determining the average time of machining proces and getting the total cost of production of machining process of a tensile test specimen. The tensile test specimen were subjected on this experiment has a circular cross-sectiolan shape which made from concrete steel with the lathe machining proces. Based on the result of the process of time and cost calculation, the tensile test specimens has an average machining time of 161,733 minutes per specimen and the cost Rp. 63.483 per specimen

PEMANFAATAN NIRA AREN MENJADI BIOETANOL UNTUK BAHAN BAKAR EMULSI YANG RAMAH LINGKUNGAN

ABSTRACTThis research purpose is to make gasohol fuel made from a mixture of ethanol and Pertamax as well as ethanol and pertalite. Ethanol used for this mixture has been through the process of reflux fermentation and distillation. Then the ethanol distillation process is carried out to obtain purity above 80%. The next stage is the process of mixing ethanol with Pertalite and Pertamax where the concentration of ethanol that will be mixed with Pertamax and Pertalite to become gasohol varies from 80% to 98% ethanol at 1% intervals. The Pertalite and Pertamax used for each sample was 7 ml while ethanol was added while shaking with a circular motion of the test tube until the solution became one phase. Using 80% ethanol in the mixture produces a Pertalite: pure ethanol: water ratio of 1: 11.65: 2.91 (in volume units), while 98% ethanol in the mixture produces a Pertalite: pure ethanol: water ratio of 1: 0.007 : 0.001 (in units of volume). For Pertamax, the minimum ethanol concentration mixed with Pertamax into a single-phase emulsion is 88% with a composition of 1: 5.91: 0.81. Keywords: ethanol, Pertalite, Pertamax. ABSTRAKPenelitian ini bertujuan untuk membuat bahan bakar gasohol dengan beberapa campuran antara etanol dan Pertamax juga etanol dan Pertalite. Tahapan yang pertama yaitu pembuatan etanol dari nira aren yang sudah terfermentasi. Kemudian dilakukan proses destilasi etanol untuk mendapatkan kemurnian di atas 80%. Tahapan selanjutnya yaitu proses pencampuran etanol dengan Pertalite dan Pertamax dimana konsentrasi etanol yang akan dicampur dengan Pertamax dan Pertalite untuk menjadi gasohol divariasikan mulai dari etanol 80% sampai 98% dengan interval 1%. Pertalite dan Pertamax yang digunakan untuk setiap sampel adalah 7 ml sementara untuk etanol ditambahkan sambil diputar dalam tabung reaksi sampai larutan menjadi satu fasa. Dengan menggunakan etanol 80% dalam campuran menghasilkan perbandingan Pertalite : etanol murni : air adalah 1: 11,65: 2,91 (dalam satuan volume), sementara untuk etanol 98% dalam campuran menghasilkan perbandingan Pertalite : etanol murni : air adalah 1: 0.007: 0.001 (dalam satuan volume). Untuk Pertamax, konsentrasi etanol minimum yang dicampur dengan Pertamax menjadi emulsi satu fase adalah 88% dengan komposisi 1: 5.91: 0.81. Konsentrasi etanol maksimum yang dicampur dengan Pertamax menjadi emulsi satu fase adalah 97% dengan perbandingan  volume Pertamax : etanol murni : air adalah 1: 0,41: 0,02.Kata kunci : etanol, Pertalite, Pertamax

Advances in ab-initio theory of Multiferroics. Materials and mechanisms: modelling and understanding

Within the broad class of multiferroics (compounds showing a coexistence of magnetism and ferroelectricity), we focus on the subclass of "improper electronic ferroelectrics", i.e. correlated materials where electronic degrees of freedom (such as spin, charge or orbital) drive ferroelectricity. In particular, in spin-induced ferroelectrics, there is not only a {\em coexistence} of the two intriguing magnetic and dipolar orders; rather, there is such an intimate link that one drives the other, suggesting a giant magnetoelectric coupling. Via first-principles approaches based on density functional theory, we review the microscopic mechanisms at the basis of multiferroicity in several compounds, ranging from transition metal oxides to organic multiferroics (MFs) to organic-inorganic hybrids (i.e. metal-organic frameworks, MOFs)Comment: 22 pages, 9 figure

Renewable Energy Optimization Report for Naval Station Newport

In 2008, the U.S. Environmental Protection Agency (EPA) launched the RE-Powering America's Land initiative to encourage the development of renewable energy (RE) on potentially contaminated land and mine sites. As part of this effort, EPA is collaborating with the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL) to evaluate RE options at Naval Station (NAVSTA) Newport in Newport, Rhode Island. NREL's Renewable Energy Optimization (REO) tool was utilized to identify RE technologies that present the best opportunity for life-cycle cost-effective implementation while also serving to reduce energy-related carbon dioxide emissions and increase the percentage of RE used at NAVSTA Newport. The technologies included in REO are daylighting, wind, solar ventilation preheating (SVP), solar water heating, photovoltaics (PV), solar thermal (heating and electric), and biomass (gasification and cogeneration). The optimal mix of RE technologies depends on several factors including RE resources; technology cost and performance; state, utility, and federal incentives; and economic parameters (discount and inflation rates). Each of these factors was considered in this analysis. Technologies not included in REO that were investigated separately per NAVSTA Newport request include biofuels from algae, tidal power, and ground source heat pumps (GSHP)

Controlling Microscopic Friction through Mechanical Oscillations

We study in detail the recent suggestions by Tshiprut et al. [Phys. Rev. Lett. 95, 016101 (2005)] to tune tribological properties at the nanoscale by subjecting a substrate to periodic mechanical oscillations. We show that both in stick-slip and sliding regimes of motion friction can be tuned and reduced by controlling the frequency and amplitude of the imposed substrate lateral excitations. We demonstrate that the mechanisms of oscillation-induced reduction of friction are different for stick-slip and sliding dynamics. In the first regime the effect results from a giant enhancement of surface diffusion, while in the second regime it is due to the interplay between washboard and oscillation frequencies that leads to the occurrence of parametric resonances. Moreover we show that for particular set of parameters it is possible to sustain the motion with the only oscillations

The impact of digital start-up founders’ higher education on reaching equity investment milestones

This paper builds on human capital theory to assess the importance of formal education among graduate entrepreneurs. Using a sample of 4.953 digital start-ups the paper evaluates the impact of start-up founding teams’ higher education on the probability of securing equity investment and subsequent exit for investors. The main findings are: (1), teams with a founder that has a technical education are less likely to remain self-financed and are more likely to secure equity investment and to exit, but the impact of technical education declines with higher level degrees, (2) teams with a founder that has doctoral level business education are less likely to remain self-financed and have a higher probability of securing equity investment, while undergraduate and postgraduate business education have no significant effect, and (3) teams with a founder that has an undergraduate general education (arts and humanities) are less likely to remain self-financed and are more likely to secure equity investment and exit while postgraduate and doctoral general education have no significant effect on securing equity investment and exit. The findings enhance our understanding of factors that influence digital start-ups achieving equity milestones by showing the heterogeneous influence of different types of higher education, and therefore human capital, on new ventures achieving equity milestones. The results suggest that researchers and policy-makers should extend their consideration of universities entrepreneurial activity to include the development of human capital

Are researchers deliberately bypassing the technology transfer office? An analysis of TTO awareness

Most universities committed to the commercialization of academic research have established technology transfer offices (TTOs). Nonetheless, many researchers bypass these TTOs and take their inventions directly to the marketplace. While TTO bypassing has typically been portrayed as deliberate and undesirable behavior, we argue that it could be unintentional as many researchers may simply be unaware of the TTO’s existence. Taking an information-processing perspective and using data on 3250 researchers in 24 European universities, we examine researcher attributes associated with TTO awareness. Our evidence confirms that only a minority of researchers are aware of the existence of a TTO at their university. TTO awareness is greater among researchers who possess experience as entrepreneurs, closed many research and consulting contracts with industry partners, conduct research in medicine, engineering or life sciences, or occupy postdoctoral positions. Policy implications of these findings are discussed

The influence of organizational culture and climate on entrepreneurial intentions among research scientists

Over the past decades, universities have increasingly become involved in entrepreneurial activities. Despite efforts to embrace their ‘third mission’, universities still demonstrate great heterogeneity in terms of their involvement in academic entrepreneurship. This papers adopts an institutional perspective to understand how organizational characteristics affect research scientists’ entrepreneurial intentions. Specifically, we study the impact of university culture and climate on entrepreneurial intentions, including intentions to spin off a company, to engage in patenting or licensing and to interact with industry through contract research or consulting. Using a sample of 437 research scientists from Swedish and German universities, our results reveal that the extent to which universities articulate entrepreneurship as a fundamental element of their mission fosters research scientists’ intentions to engage in spin-off creation and intellectual property rights, but not industry-science interaction. Furthermore, the presence of university role models positively affects research scientists’ propensity to engage in entrepreneurial activities, both directly and indirectly through entrepreneurial self-efficacy. Finally, research scientists working at universities which explicitly reward people for ‘third mission’ related output show higher levels of spin-off and patenting or licensing intentions. This study has implications for both academics and practitioners, including university managers and policy makers