Strategi Pengembangan Agroindustri Keripik Pisang (Studi Kasus pada Seorang Pengusaha Keripik Pisang di Desa Hegarmanah Kecamatan Cidolog Kabupaten Ciamis)

Penelitian ini bertujuan untuk mengetahui besarnya biaya, penerimaan dan pendapatan, faktor internal dan eksternal yang berpengaruh terhadap pengembangan agroindustri keripik pisang, alternatif strategi yang dapat diterapkan dalam pengembangan agroindustri keripik pisang di Desa Hegarmanah Kecamatan Cidolog Kabupaten Ciamis. Jenis penelitian yang digunakan dalam penelitian ini adalah metode studi kasus. Data yangdikumpulkan meliputi data primer dan data sekunder. Penarikan responden dalam penelitian ini dilakukan purposive sampling yaitu penetuan sampel dengan pertimbangan tertentu yang dipandang dapat memberikan data secara maksimal, maka responden yang diambil satu orang pengusaha keripik pisang dan sebagai responden pendukung yaitu satu orang Pemerintah Desa Hegarmanah dan satu orang dari Dinas Pertanian.Hasil penelitian menunjukan bahwa:1) Besarnya biaya total yang dikeluarkan oleh pengusaha keripik pisang dalam satu kali proses produksi sebesar Rp 1.369.385,67, penerimaannya sebesar Rp 2.500.000,00 dan pendapatannya sebesar Rp 1.130.614,33.2) Faktor internal dan eksternal yang berpengaruh pada pengembangan agroindustri keripik pisang di Desa Hegarmanah Kecamatan Cidolog Kabupaten Ciamis terdiri dari kekuatan, kelemahan dan peluang, ancaman. Faktor-faktor yang menjadi kekuatan yaitu tersedianya cukup jumlah tenaga kerja, produksi mudah dilakukan, produk keripik pisang yang tahan lama, harga produkyang terjangkau. Sedangkan faktor-faktor yang menjadi kelemahan yaitu keterbatasan permodalan, kualitas SDM yang masih kurang, pengemasan produk masih sederhana, dan promosi masih kurang. Faktor-faktor yang menjadi peluang yaitu tidak ada pesaing produk sejenis disatu daerah, pangsa pasar yang masih luas, permintaan semakin meningkat, cuaca tidak mempengaruhi produksi. Faktor-faktor yang menjadi ancaman yaitu kelangkaan bahanbaku, fluktuasi harga bahan baku, kurang adanya peran dari pemerintah, dan kenaikan harga sarana produksi.3) Alternatif strategi yang dapat diterapkan dalam pengembangan agroindustri keripik pisang di Desa Hegarmanah Kecamatan Cidolog Kabupaten Ciamis yaitu mempertahankan kualitas produksi dan pengembangan pasar, mempertahankan kontinyuitas produksi untuk memenuhi permintaan, optimalisasi kualitas SDM untuk memenuhi permintaan produk, diversifikasi produk untuk memenuhi pangsa pasar, pengelolaan tenaga kerja dan ketersediaan bahan baku,keseragaman harga jual dengan peran serta pengawasan pemerintah, penganekaragaman pengemasan untuk memaksimalkan produksi dan menjalin kerja sama dengan pihak terkait dalam menyikapi permodalan

Confinement Effects in Lewis Acid-Catalyzed Sugar Conversion: Steering Toward Functional Polyester Building Blocks

We report the use of solid Lewis acid catalysts for the conversion of tetrose sugars to four-carbon α-hydroxy acid esters (C_4-AHA), which are useful as functional polyester building blocks. Sn-β was by far the most active and selective catalyst, yielding up to 80% methyl vinyl glycolate (MVG), methyl-4-methoxy-2-hydroxybutanoate (MMHB), and α-hydroxy-γ-butyrolactone (HBL) combined at 95% conversion. A very high turnover frequency (TOF) of 330 mol_(C4-AHA) mol_(Sn) h^(–1) was attained using Sn-β, a more than 6-fold increase compared with homogeneous SnCl_4·5H_2O. It is shown that, using different Sn-based catalysts with various pore sizes, the product distribution is strongly dependent on the size of the catalyst pores. Catalysts containing mainly mesopores, such as Sn-MCM-41 or Sn-SBA-15, prefer the production of the more bulky MMHB, whereas microporous catalysts such as Sn-β or Sn-MFI favor the production of MVG. This effect can be further enhanced by increasing the reaction temperature. At 363 K, only 20% MVG is attained using Sn-β, but at 433 K, this increases to 50%. Using a kinetic analysis, it was found that, in microporous catalysts, steric hindrance near the Sn active site in the catalyst pores plays a dominant role in favoring the reaction pathway toward MVG. Moreover, the selectivity toward both products is kinetically controlled

Loss of multidrug resistance protein 1 expression and folate efflux activity results in a highly concentrative folate transport in human leukemia cells.

We studied the molecular basis of the up to 46-fold increased accumulation of folates and methotrexate (MTX) in human leukemia CEM-7A cells established by gradual deprivation of leucovorin (LCV). CEM-7A cells consequently exhibited 10- and 68-fold decreased LCV and folic acid growth requirements and 23-25-fold hypersensitivity to MTX and edatrexate. Although CEM-7A cells displayed a 74-86-fold increase in the reduced folate carrier (RFC)-mediated influx of LCV and MTX, RFC overexpression per se cannot induce a prominently increased folate/MTX accumulation because RFC functions as a nonconcentrative anion exchanger. We therefore explored the possibility that folate efflux activity mediated by members of the multidrug resistance protein (MRP) family was impaired in CEM-7A cells. Parental CEM cells expressed substantial levels of MRP1, MRP4, poor MRP5 levels, whereas MRP2, MRP3 and breast cancer resistance protein were undetectable. In contrast, CEM-7A cells lost 95% of MRP1 levels while retaining parental expression of MRP4 and MRP5. Consequently, CEM-7A cells displayed a 5-fold decrease in the [(3)H]folic acid efflux rate constant, which was identical to that obtained with parental CEM cells, when their folic acid efflux was blocked (78%) with probenecid. Furthermore, when compared with parental CEM, CEM-7A cells accumulated 2-fold more calcein fluorescence. Treatment of parental cells with the MRP1 efflux inhibitors MK571 and probenecid resulted in a 60-100% increase in calcein fluorescence. In contrast, these inhibitors failed to alter the calcein fluorescence in CEM-7A cells, which markedly lost MRP1 expression. Replenishment of LCV in the growth medium of CEM-7A cells resulted in resumption of normal MRP1 expression. These results establish for the first time that MRP1 is the primary folate efflux route in CEM leukemia cells and that the loss of folate efflux activity is an efficient means of markedly augmenting cellular folate pools. These findings suggest a functional role for MRP1 in the maintenance of cellular folate homeostasis

Biomass transformations with Sn in dealuminated ß zeolites

The concept of biorefinery, transforming biological feedstock into valuable chemicals, has gained in interest the last decades due to depleting cheap oil reserves, but also due to an increasing environmental awareness. An important challenge before switching to a biomass-driven society, is to transform biomolecules like triglycerides and lignocellulosics into added-value chemicals efficiently, for which new developments in the chemical processing of such biomolecules are crucial. The design of new catalytic materials, able to efficiently and selectively convert the intended reactions, is an important topic in this progress. Many new or modified catalytic materials with various catalytic entities and capabilities are being researched that can defy the new challenges associated with biomass conversion. Reagent molecules are now more polar and reactive than those we used to convert with acid/base and redox catalysis, and the new reactions are likely to be processed in aqueous conditions at elevated temperatures. Lewis acidity has always been an important type of catalysis in the fine chemistry, but also in the petrochemistry. In the group of water stable Lewis acid catalysts, Sn-containing materials of which the acid Sn-beta (Snβ) is the most studies member receive a lot of attention currently. Snβ is capable of catalyzing several interesting biomass related reactions, including the isomerization and epimerization of monosaccharides, but is also allows the direct conversion of sugars into lactate esters and condensation C-C coupling chemistry. Furthermore, the materials also display excellent catalytic properties in more organically oriented reactions such as Baeyer-Villiger oxidations and Meerwein-Ponndorf-Verley reductions. Though Snβ is a proven catalysts, its synthesis is arduous. Long synthesis times and hazardous chemicals are needed to incorporate Sn into the zeolite framework, impeding industrial scale use of the catalytic material. The focus of this doctoral research is to find an alternative and more sustainable synthesis procedure for the Sn-containing catalyst. Previous efforts succeeded in shortening the synthesis times by modifying the traditional hydrothermal procedure, but they still need toxic chemicals. Another approach, practiced here in this work, introduces Sn into commercial beta zeolite structures, a so-called post-synthesis procedure. This method prevents the use of hazardous chemicals and only short synthesis times are needed, but the catalytic activity of materials which have been synthesized following this approach until today, is significantly lower than its hydrothermal counterpart. The research presented in this work therefore attempts a novel synthesis method, combining both synthesis times and practical operations from the post-synthetic procedures without compromising the catalytic properties, characterized by a high activity and excellent catalyst stability. The novel synthesis procedure grafts Sn precursor salts onto a dealuminated commercial Beta zeolite during reflux in dry isopropanol. Up to 2 wt% of monoatomic active Sn4+ atoms can be introduced into the zeolite framework without formation of extraframework non-catalytically active Sn-species. Essential steps in the synthesis method and requirements of chemicals and conditions were studied and discussed in this work. The catalytic properties of the material were tested in several biomass and fine chemicals related transformations. Most surprisingly, it appears that different reaction types required somewhat different Snβ catalysts for their optimal performance. Therefore, different Sn active sites, monomeric to oligomeric SnOx in nature, are possible in the same beta framework and each reaction type requires a different optimization synthesis procedure. Biomass conversion usually requires multi-step or cascade type of reactions to form the desired product. One-pot conversions combine many different steps together, which is especially of interest when the intermediate chemicals are very reactive or hazardous. Design of multiple site catalysts is therefore paramount in biomass conversion. The great challenge is to incorporate the different active sites in balance with the requirements of the reaction kinetics. The presented novel synthesis procedure is highly versatile and therefore ideal to design such multi-active site catalysis. Partial, instead of complete, removal of Al in the original structure of Beta allows the presence of Brønsted acidity, next to the Lewis acidity of Sn. This bifunctional catalyst model catalyst showed great potential in the conversion of carbohydrate to lactate esters. In essence, this reaction requires multiple steps, while the reaction rate is determined by a dehydration step. Accelerating this step with the acidity greatly improved the reaction rate. Interestingly, the cooperative effect is only valid when the two different catalytic sites are close to each other, ie. in the same zeolite crystal. Other important reactions like glucose to HMF and levulinic acid might also benefit from the presence of the two sites, though a different balance is anticipated. Though Snβ has already been discovered in 1997, the characteristics of the genuine active Sn site is under debate. Next to the site characteristics, there is also discussion on the importance of the active site pocket, either containing nearby silanols or not. The latter might assist in coordinating the molecules in the active site pocket or it effects the polarity, and thus the adsorption (and intrazeolitic concentration), of molecules. This work noticed that post-synthetic synthesis leads to a different active Sn site. The Sn-atom is less coordinated to the framework, but therefore shows a stronger Lewis acidity. The site appears like a coordinative binding, with separating acid – base entities due to the constraints in the active site, dictated by the rigid zeolite frame. That Sn sites in the new and old material are different might not come to a surprise, as Sn is incorporated in Al-removal sites in the post-synthesis procedure, while the incorporation of Sn in the hydrothermal synthesis runs differently. Catalytic consequences of these differences were demonstrated by detailed kinetic analysis of two reaction types for which a better activity per Sn was observed in the grafted material. In Baeyer-Villiger oxidation, both entropic (transition state stabilization) and enthalpic (increased Lewis acid strength) effects were noticed, whereas only entropic benefits (site accessibility) were found in case of a bimolecular Meerwein-Ponndorf-Verley reaction. The new Sn catalyst presented in this work thus shows great catalytic opportunities in biomass conversion. It is not only very active, its production for large scale application is practical. Moreover, the synthesis procedure allows tailoring the catalytic properties, and can be used for other active site types like Zr, Ce and Hf, which can be of great interest in the development of various biorefinery processes.status: publishe

Sn beta-zeolite catalyzed oxido-reduction cascade chemistry with biomass-derived molecules

High activity of post-synthetically synthesized Sn-beta, producing novel caprolactone polymer building blocks, is demonstrated in Meerwein-Ponndorf-Verley (MPV), Oppenauer (OPO), Baeyer-Villiger (BV) and cascade reactions thereof with biomass-derived molecules.crosscheck: This document is CrossCheck deposited related_data: Supplementary Information copyright_licence: The Royal Society of Chemistry has an exclusive publication licence for this journal history: Received 8 January 2016; Accepted 17 April 2016; Accepted Manuscript published 18 April 2016; Advance Article published 27 April 2016; Version of Record published 10 May 2016status: publishe

Post-synthesis Snß: An exploration of synthesis parameters and catalysis

© 2015 Elsevier Inc. All rights reserved. Snβ is probably one of the best water tolerating heterogeneous Lewis acids for liquid phase catalysis. Instead of applying the usual lengthy hydrothermal synthesis to prepare Snβ, this contribution uses a more hands-on two-step synthesis method, involving the grafting of Sn precursors in isopropanol under reflux conditions on a commercial β zeolite that was dealuminated in acid. Among several reference synthesis procedures, this Sn introduction method resulted in active Sn catalytic sites. Taking advantage of this practical method, several synthesis parameters were explored and their impact on the catalytic activity in four different Lewis acid catalyzed reactions is discussed. The adsorption isotherm of SnIV in isopropanol over a broad range of Sn salt concentrations at reflux temperature is presented and discussed in relation with FTIR spectroscopy, UV-vis absorption characteristics and the porosity of the materials. The study reveals a selective Sn uptake, up to 2 wt% Sn loading, into silanol nests of the dealuminated precursor, forming a diversity of mononuclear SnIV. Higher Sn loadings result in less active Sn (hydrous) extraframework oxide phases, which also cause partial blockage of the zeolite micropores. Depending on the reaction type under study, space time yield may increase with increasing Sn loading, but the activity per Sn is always lower. Therefore it is concluded that a preferred synthesis should form high contents of isolated Sn active sites, especially for sugar isomerization and intermolecular Meerwein-Ponndorf-Verley, while the other reaction types like Baeyer-Villiger is also sufficiently catalyzed by the small Sn oxide clusters, albeit less actively.publisher: Elsevier articletitle: Post-synthesis Snβ: An exploration of synthesis parameters and catalysis journaltitle: Journal of Catalysis articlelink: http://dx.doi.org/10.1016/j.jcat.2015.06.023 content_type: article copyright: Copyright © 2015 Elsevier Inc. All rights reserved.status: publishe

Immobilized Grubbs Catalysts on Mesoporous Silica Materials: Insight into Support Characteristics and Their Impact on Catalytic Activity and Product Selectivity

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Active matrix display devices and methods of driving the same

An active matrix display device comprises an array of pixels arranged in rows and columns and a column driver circuit for providing pixel drive signals to the columns of pixels. The column driver circuit comprises an array of current source circuits, a respective current source circuit being provided for each column of pixels, and each current source circuit comprises a current source (70; 80; 90), an output driver (71), a storage capacitor (72) connected to the output of the output driver; and a supply switch (78) for controlling the time during which the current source supplies current to or drains current from the storage capacitor (72), thereby determining the output voltage of the output driver.; The device further comprises a mapping means (86) for deriving from a pixel drive level a digital value which represents a time period for the control of the supply switch (78) of each current source circuit

Highly Accessible, Stable and Active Sn Catalysis in Partially Dealuminated Beta Zeolites

Sn-beta zeolite is a powerful Lewis acid catalyst. Recently it was shown that this material shows great activity and stability in carbohydrate-related conversions in water and other solvents. Among these reactions are isomerization of sugars and retro-aldol reactions yielding alkyl lactates, both essential steps in a carbohydrate-based renewable feedstock. Unfortunately, the synthesis of this catalyst is not straightforward. Long hydrothermal synthesis times are needed and the use of corrosive hydrogen fluoride is unavoidable. We present a simple way to synthesize a Sn-containing zeolite by grafting affordable Sn-species onto partially dealuminated beta zeolites. The presence of aluminum results in Brønsted acidity, the presence of tin yields Lewis acidity. This synthesis method allows to synthesize the Sn-beta zeolite in a couple of hours, with tunable parameters an without the use of hydrogen fluoride. The catalytic activity of the catalyst was tested in different reactions, and compared to the traditional synthesized Snβ. Catalysts synthesized by the grafting procedure show very high activities for all the tested reactions, with turnover frequencies per Sn much higher than the original Snβ.status: publishe

Mg-O-Si chemical bond formation in light burned magnesia and fumed silica mixture during mechanical activation

Mg-O-Si chemical bond formation in a light burned magnesia (MgO) and fumed silica (SiO₂) mixture during mechanical activation was investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), magic angle spinning nuclear magnetic resonance (MAS-NMR), and X-ray photoelectron spectroscopy (XPS). Crystallinity and intrinsic structure changes of the starting mixture during high-energy milling were examined by XRD. The formation of new Mg-O-Si chemical bonds of the ground mixture was illustrated by the incorporation of Mg²⁺ in Si-O-Si linkages, the appearance of new resonance in the ²⁹Si NMR spectrum and the decrease of the Si 2p binding energy. The formation of Mg-O-Si chemical bonds created during grinding partly contributed to the lowered temperature of complete forsterite formation from 1400 to 1100 °C.status: publishe