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

Analisis Pengaruh Radiasi Gelombang Mikro Pada Struktur Kristal Pati (Starch)

Penelitian ini bertujuan untuk menganalisa Perubahan struktur Kristal sampel setelah diberi perlakuan awal (pretreatment) dengan cara memanfaatkan radiasi gelombang Elektromagnetik. Alat yang akan digunakan dalam penelitian ini adalah microwave sedangkan sampel atau substrat yang dipilih adalah pati singkong yang telah dihaluskan dan dikeringkan di bawah sinar matahari selama beberapa waktu. Bahan yang telah di pretreatment dengan microwave selanjutnya dilakukan pengukuran dengan menggunakan SEM, XRD dan FTIR. Karakterisasi substrat yang telah mengalami proses pretreatment kemudian dibandingkan dengan sampel alami.SEM menunjukan bahwa permukaan granula dari sampel yang dilakukan pretreatment mengalami Perubahan. Dari pola XRD memperlihatkan Perubahan Kristal menjadi lebih amorf pada sudut antara 15-24°, sedangkan pola FTIR terjadi pergeseran wilayah serapan gelombang inframerah pada sampel yang dilakukan pretreatmentThis research is aimed to analyze the change of sample crystal structure after it was given a pretreatment by utilizing the microwave radiation. The device that was used in this research was a microwave set, while the chosen sample or subtrate was starch which has been mashed and dried under the sunlight for days. Material that was conducted a pretreatment was then measured using SEM, XRD and FTIR. Characterization of the subtrate that has been undergone the pretreatment was then compared to the natural sample.The SEM showed that the granule surface of treated substrate changed while the XRD pattern displayed a transformation to be more amorphous at the angles of 15-24°. The FTIR pattern revealed the absorption of infrared wave shifted for the sample treated by microwave compared to that of original substrate

Space of State Vectors in PT Symmetrical Quantum Mechanics

Space of states of PT symmetrical quantum mechanics is examined. Requirement that eigenstates with different eigenvalues must be orthogonal leads to the conclusion that eigenfunctions belong to the space with an indefinite metric. The self consistent expressions for the probability amplitude and average value of operator are suggested. Further specification of space of state vectors yield the superselection rule, redefining notion of the superposition principle. The expression for the probability current density, satisfying equation of continuity and vanishing for the bound state, is proposed.Comment: Revised version, explicit expressions for average values and probability amplitude adde

Inelastic Quantum Transport

We solve a Schrodinger equation for inelastic quantum transport that retains full quantum coherence, in contrast to previous rate or Boltzmann equation approaches. The model Hamiltonian is the zero temperature 1d Holstein model for an electron coupled to optical phonons (polaron), in a strong electric field. The Hilbert space grows exponentially with electron position, forming a non-standard Bethe lattice. We calculate nonperturbatively the transport current, electron-phonon correlations, and quantum diffusion. This system is a toy model for the constantly branching ``wavefunction of the universe''.Comment: revtex, 13 pages, 4 figure

Constraints on Crustal Structure in the Vicinity of the Adriatic Indenter (European Alps) From Vp and Vp/Vs Local Earthquake Tomography

In this study, 3-D models of P-wave velocity (Vp) and P-wave and S-wave ratio (Vp/Vs) of the crust and upper mantle in the Eastern and eastern Southern Alps (northern Italy and southern Austria) were calculated using local earthquake tomography (LET). The data set includes high-quality arrival times from well-constrained hypocenters observed by the dense, temporary seismic networks of the AlpArray AASN and SWATH-D. The resolution of the LET was checked by synthetic tests and analysis of the model resolution matrix. The small inter-station spacing (average of ∼15 km within the SWATH-D network) allowed us to image crustal structure at unprecedented resolution across a key part of the Alps. The derived P velocity model revealed a highly heterogeneous crustal structure in the target area. One of the main findings is that the lower crust is thickened, forming a bulge at 30–50 km depth just south of and beneath the Periadriatic Fault and the Tauern Window. This indicates that the lower crust decoupled both from its mantle substratum as well as from its upper crust. The Moho, taken to be the iso-velocity contour of Vp = 7.25 km/s, agrees with the Moho depth from previous studies in the European and Adriatic forelands. It is shallower on the Adriatic side than on the European side. This is interpreted to indicate that the European Plate is subducted beneath the Adriatic Plate in the Eastern and eastern Southern Alps

Social and cultural origins of motivations to volunteer a comparison of university students in six countries

Although participation in volunteering and motivations to volunteer (MTV) have received substantial attention on the national level, particularly in the US, few studies have compared and explained these issues across cultural and political contexts. This study compares how two theoretical perspectives, social origins theory and signalling theory, explain variations in MTV across different countries. The study analyses responses from a sample of 5794 students from six countries representing distinct institutional contexts. The findings provide strong support for signalling theory but less so for social origins theory. The article concludes that volunteering is a personal decision and thus is influenced more at the individual level but is also impacted to some degree by macro-level societal forces

Stakeholder Theory and Marketing: Moving from a Firm-Centric to a Societal Perspective

This essay is inspired by the ideas and research examined in the special section on “Stakeholder Marketing” of the Journal of Public Policy & Marketing in 2010. The authors argue that stakeholder marketing is slowly coalescing with the broader thinking that has occurred in the stakeholder management and ethics literature streams during the past quarter century. However, the predominant view of stakeholders that many marketers advocate is still primarily pragmatic and company centric. The position advanced herein is that stronger forms of stakeholder marketing that reflect more normative, macro/societal, and network-focused orientations are necessary. The authors briefly explain and justify these characteristics in the context of the growing “prosociety” and “proenvironment” perspectives—orientations that are also in keeping with the public policy focus of this journal. Under the “hard form” of stakeholder theory, which the authors endorse, marketing managers must realize that serving stakeholders sometimes requires sacrificing maximum profits to mitigate outcomes that would inflict major damage on other stakeholders, especially society

Solvable simulation of a double-well problem in PT symmetric quantum mechanics

Within quantum mechanics which works with parity-pseudo-Hermitian Hamiltonians we study the tunneling in a symmetric double well formed by two delta functions with complex conjugate strengths. The model is exactly solvable and exhibits several interesting features. Besides an amazingly robust absence of any PT symmetry breaking, we observe a quasi-degeneracy of the levels which occurs all over the energy range including the high-energy domain. This pattern is interpreted as a manifestation of certain "quantum beats".Comment: 12 pages incl. 7 figure

A critical evaluation of the fish early-life stage toxicity test for engineered nanomaterials: experimental modifications and recommendations

There are concerns that regulatory toxicity tests are not fit for purpose for engineered nanomaterials (ENMs) or need modifications. The aim of the current study was to evaluate the OECD 210 fish, early-life stage toxicity test for use with TiO2 ENMs, Ag ENMs, and MWCNT. Both TiO2 ENMS (≤160 mg l(-1)) and MWCNT (≤10 mg l(-1)) showed limited acute toxicity, whilst Ag ENMs were acutely toxic to zebrafish, though less so than AgNO3 (6-day LC50 values of 58.6 and 5.0 µg l(-1), respectively). Evidence of delayed hatching, decreased body length and increased muscle width in the tail was seen in fish exposed to Ag ENMs. Oedema (swollen yolk sacs) was also seen in fish from both Ag treatments with, for example, mean yolk sac volumes of 17, 35 and 39 µm(3) for the control, 100 µg l(-1) Ag ENMs and 5 µg l(-1) AgNO3 treatments, respectively. Among the problems with the standard test guidelines was the inability to maintain the test solutions within ±20 % of nominal concentrations. Pronounced settling of the ENMs in some beakers also made it clear the fish were not being exposed to nominal concentrations. To overcome this, the exposure apparatus was modified with the addition of an exposure chamber that ensured mixing without damaging the delicate embryos/larvae. This allowed more homogeneous ENM exposures, signified by improved measured concentrations in the beakers (up to 85.7 and 88.1 % of the nominal concentrations from 10 mg l(-1) TiO2 and 50 µg l(-1) Ag ENM exposures, respectively) and reduced variance between measurements compared to the original method. The recommendations include: that the test is conducted using exposure chambers, the use of quantitative measurements for assessing hatching and morphometrics, and where there is increased sensitivity of larvae over embryos to conduct a shorter, larvae-only toxicity test with the ENMs