scholarly journals Ozone Oxidation of Kraft Bamboo Pulp for Preparation of Nanofibrillated Cellulose

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Mingyou Liu ◽  
Xia Chen ◽  
Xiaofei Tian
Keyword(s):  
Aspect Ratio ◽  
Nanofibrillated Cellulose ◽  
Kappa Number ◽  
Efficient Production ◽  
Bamboo Pulp ◽  
Alternative Approach ◽  
Carboxylate Content ◽  
Pulp Consistency ◽  
20 Nm ◽  
Optimized Conditions

The influence of ozonation on the homogenization of Kraft bamboo pulp (KBP) for the production of nanofibrillated cellulose (NFC) was studied. Using optimized conditions for ozonation, that is, pulp consistency 35%, ozone dosage 0.87% (v/w), and pH=2.5, the kappa number and viscosity of KBP decreased from 10.8 to 2.8 and from 1024 mL∙g−1 to 258 mL∙g−1, respectively, while the crystallinity and carboxylate content increased from 36.2% to 48% and 0.93 mmol/g to 1.26 mmol/g, respectively. The ozonation-treated KPB was used as the substrate for NFC preparation through homogenization. With a width of 10–20 nm and length≥250 nm, the prepared NFC had a high aspect ratio of length versus width. Ozonation can be used as an alternative approach to promote the efficient production of NFC from KBP.

Study on Bamboo Kraft Pulping with DTPMPA

2013 ◽  
Vol 781-784 ◽  
pp. 2658-2661
Author(s):  
Hong Xia Gao ◽  
Xiu Qiong Guan ◽  
Chun Yue Ding
Keyword(s):  
Phosphonic Acid ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Maximum Temperature ◽  
Pulp Yield ◽  
Waste Liquor ◽  
Diethylene Triamine ◽  
Bamboo Pulp ◽  
Cooking Temperature ◽  
Optimized Conditions

DTPMPA (Diethylene Triamine Penta Methylene Phosphonic Acid) was used as cooking additive in Bamboo pulping. The effect of cooking parameters such as alkali charge, maximum cooking temperature, and time at maximum temperature on bamboo kraft pulping adding additive Diethylene Triamine Penta Methylene Phosphonic Acid was studied. The results show that the optimized bamboo kraft pulping conditions are: alkali charge 17%, maximum cooking temperature 162°C, and time at maximum temperature 60min when DTPMPA dosage is 0.4%. On the optimized conditions of cooking, the highest screened bamboo pulp yield 49.52%, the kappa number of bamboo pulp is 24.68, residual alkali in kraft waste liquor 3.62g/L .

Application of Chelating Agents as Cooking Aids in Bamboo Pulping

2013 ◽  
Vol 750-752 ◽  
pp. 1520-1523
Author(s):  
Hong Xia Gao ◽  
Wen Hua He ◽  
Xiu Qiong Guan ◽  
Chun Liu ◽  
Bo Yuan
Keyword(s):  
Phosphonic Acid ◽  
Chelating Agents ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Diethylene Triamine ◽  
Bamboo Pulp ◽  
Kraft Cooking ◽  
Pulp Strength

The effect of chelating agents Diethylene Triamine Penta Methylene Phosphonic Acid in bamboo kraft cooking was studied. The results show that the bamboo pulp yield was 49.52% when DTPMPA dosage is 0.4%, at the same time the Kappa number was lower. With the increasing of DTPMPA dosage in bamboo kraft pulping, the bamboo pulp strength was increased.

Application of Diethylene Triamine Penta Methylene Phosphonic Acid in Bamboo Pulping

2012 ◽  
Vol 550-553 ◽  
pp. 3331-3334
Author(s):  
Hong Xia Gao
Keyword(s):  
Phosphonic Acid ◽  
Kappa Number ◽  
Diethylene Triamine ◽  
Bamboo Pulp ◽  
Kraft Cooking ◽  
Pulp Properties

The effect of Diethylene Triamine Penta Methylene Phosphonic Acid in bamboo kraft cooking was studied. The results show that the bamboo pulp properties are optimal when DTPMPA dosage is 0.4%. The optimal properties are as follows: the kappa number is 16.4, brightness is 37.8%, and the screened yield is 41.9%.

scholarly journals Small-Diameter Magnetic and Metallic Nanowire Arrays Grown in Anodic Porous Alumina Templates Anodized in Selenic Acid

2021 ◽  
Author(s):  
Mahdieh Ahmadzadeh ◽  
Mohammad Almasi Kashi ◽  
Mohammad Noormohammadi ◽  
Abdolali Ramazani
Keyword(s):  
Oxalic Acid ◽  
Porous Alumina ◽  
Small Diameter ◽  
Nanowire Arrays ◽  
Pore Filling ◽  
Selenic Acid ◽  
Anodic Porous Alumina ◽  
Formation Pattern ◽  
20 Nm ◽  
Optimized Conditions

Abstract Despite the introduction of selenic acid for anodic porous alumina (APA) preparation with small nanopore diameters (< 20 nm), no attempt has been made to use it in the fabrication of small-diameter magnetic and metallic nanowire arrays. In this paper, considering the high cost of selenic acid, it has been attempted to initially use oxalic acid in preparation of an ordered pattern in the first anodization step, and then employ selenic acid for the second anodization step by matching the appropriate voltage. By investigating the nanopore formation pattern in both acids, it was shown that the nanopores formed in the selenic acid had considerably smaller diameter (13 nm) than that of oxalic acid (35 nm). Under optimized conditions of electrodeposition, various metals were then grown in the selenic APA templates in order to fabricate nanowires with small diameters. The pore filling percentage and crystalline properties were also investigated.

scholarly journals Importance of Neighborhood Aspect Ratio and Storm Climate to Adaptation Efforts to Reduce Coastal Flood Mortality

2022 ◽  
Vol 7 ◽  
Author(s):  
Fanglin Zhang ◽  
Philip M. Orton
Keyword(s):  
Aspect Ratio ◽  
Sea Level Rise ◽  
Risk Reduction ◽  
Sea Level ◽  
Mortality Risk ◽  
Flood Risk ◽  
General Idea ◽  
Physical Factors ◽  
Alternative Approach ◽  
Flood Risk Reduction

Low-lying Coastal Landfill Neighborhoods (CLaNs) often have a large aspect ratio, defined here as the coastline length divided by neighborhood width, due to the common practice of reclaiming fringing wetlands along tidal waterways. Flood risk reduction for CLaNs frequently involves elevated barriers, in the form of berms, seawalls, or levees, which reduce risk but cannot completely eliminate residual risk (e.g., due to overtopping during extreme events). Managed retreat is an alternative approach for flood risk reduction, the general idea of which is to strategically ban development in hazard zones, relocate structures, and/or abandon land. This study aims at exploring the tradeoffs between elevated barriers and managed retreat in terms of both CLaN aspect ratio and storm climate, for both short-term and long-term risk reduction with sea-level rise. Hydrodynamic flood modeling of an idealized CLaN protected by different adaptation plans is used to simulate flood conditions and mortality for a range of storm surge amplitudes for both the present-day and under different sea-level rise scenarios. Results show that for a berm and a case of managed retreat of an equal cost, retreat becomes more beneficial than the berm in terms of mortality risk reduction for neighborhoods with a larger aspect ratio. The study also shows that berms are generally less effective for reducing mortality in regions with less common but higher intensity storms. This study reveals the potential of idealized modeling to provide fundamental insights on the physical factors influencing the efficacy of different adaptation strategies for mortality risk reduction.

Effect of nanofibrillated cellulose made from enzyme-pretreated bamboo pulp on paper strength

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 964-978
Author(s):  
Hae Min Jo ◽  
Ji Young Lee ◽  
Su Ho Kim ◽  
Yeon Hui Lee
Keyword(s):  
Physical Properties ◽  
Kraft Pulp ◽  
Nanofibrillated Cellulose ◽  
Raw Material ◽  
Paper Strength ◽  
Strength Enhancement ◽  
Tensile Index ◽  
Similar Improvement ◽  
Bamboo Pulp ◽  
Enzyme Pretreatment

The applicability of bleached bamboo kraft pulp (Ba-BKP) was explored as a raw material for the manufacture of nanofibrillated cellulose (EN-NFC) made of enzyme-pretreated pulps and the effects of the EN-NFC on enhancing paper strength. The Ba-BKP was pretreated using an endo-glucanase enzyme at 50 °C and pH 6, after which the EN-NFC was made by micro-grinding. Bleached hardwood kraft pulp (Hw-BKP) was used as a control, and the non-enzymatic refining pretreatment of BKPs was compared with the enzyme pretreatment. The EN-NFC was incorporated into handsheets, and the sheet strengths were measured. The physical properties of the NFC made from the Ba-BKP were similar to those made from the Hw-BKP. The NFC prepared following enzyme pretreatment were smaller and more uniform than those pretreated with refining. The EN-NFC made from the Ba-BKP was effective at enhancing tensile index by 52.7%, and burst index by 210.2% when 2% of EN-NFC was added in the furnish, and those of handsheets containing the EN-NFC made from Hw-BKP showed the similar improvement. Therefore, Ba-BKP can be used as a raw material for the manufacture of EN-NFC that confers similar physical properties and strength enhancement to paper as those made from Hw-BKP.

Sharp Needles: Fabrication of Tungsten Nanotips by AC Electrochemical Etching and Laser Enhanced Etching for Nanoprobing on Interconnects of Advanced Technology Nodes.

2013 ◽  
Vol 1553 ◽  
Author(s):  
M. K. Dawood ◽  
Z.H. Mai ◽  
T. H. Ng ◽  
H. Tan ◽  
P.K. Tan ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Laser Irradiation ◽  
High Aspect Ratio ◽  
Electrochemical Etching ◽  
Etching Process ◽  
Advanced Technology ◽  
Radius Of Curvature ◽  
20 Nm ◽  
Technology Nodes ◽  
Contact Size

ABSTRACTSharper nanotips are required for application in nanoprobing systems due to a shrinking contact size with each new transistor technology node. We describe a two-step etching process to fabricate W nanotips with controllable tip dimensions. The first process is an optimized AC electrochemical etching in KOH to fabricate nanotips with a radius of curvature (ROC) down to 90 nm. This was followed by a secondary nanotip sharpening process by laser irradiation in KOH. High aspect ratio nanotips with ROC close to 20 nm were obtained. Finally we demonstrate the application of the fabricated nanotips for nanoprobing on advanced technology SRAM devices.

An Alternative Approach to the High Aspect Ratio Wing With Jet Flap by Matched Asymptotic Expansions

1978 ◽  
Vol 29 (4) ◽  
pp. 227-250 ◽  
Author(s):  
T. Kida ◽  
Y. Miyai
Keyword(s):  
Aspect Ratio ◽  
Asymptotic Expansions ◽  
High Aspect Ratio ◽  
Three Dimensional ◽  
Matched Asymptotic Expansions ◽  
Alternative Approach ◽  
Line Theory ◽  
Physical Insight ◽  
Lifting Line ◽  
Lifting Line Theory

SummaryAn alternative method is described for solving the problem of a three-dimensional jet-flapped wing with a high aspect-ratio. This method is similar to the lifting-line theory of Kerney6 or Tokuda7, but differs in that the method of matched asymptotic expansions is applied to an integral equation, derived from the lifting surface theory, rather than a partial differential equation. The advantage of the present method over those used previously is that the necessary outer solutions are obtained directly; it is not necessary to rely upon physical insight or considerable ingenuity. The final results are different from those obtained by the previous authors; it is shown that the present result is correct, by noting some errors in the earlier theories.

High aspect ratio InGaAs FinFETs with sub-20 nm fin width

2016 ◽  
Author(s):  
Alon Vardi ◽  
Jianqiang Lin ◽  
Wenjie Lu ◽  
Xin Zhao ◽  
Jesus A. del Alamo
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
20 Nm

scholarly journals Biocatalyzed Flow Oxidation of Tyrosol to Hydroxytyrosol and Efficient Production of Their Acetate Esters

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1142
Author(s):  
Francesca Annunziata ◽  
Martina L. Contente ◽  
Cecilia Pinna ◽  
Lucia Tamborini ◽  
Andrea Pinto
Keyword(s):  
Biological Activities ◽  
Primary Alcohol ◽  
Organic Layer ◽  
Efficient Production ◽  
Water Medium ◽  
Catch And Release ◽  
Health Related ◽  
Aqueous Flow ◽  
The Cost ◽  
Optimized Conditions

Tyrosol (Ty) and hydroxytyrosol (HTy) are valuable dietary phenolic compounds present in olive oil and wine, widely used for food, nutraceutical and cosmetic applications. Ty and HTy are endowed with a number of health-related biological activities, including antioxidant, antimicrobial and anti-inflammatory properties. In this work, we developed a sustainable, biocatalyzed flow protocol for the chemo- and regio-selective oxidation of Ty into HTy catalyzed by free tyrosinase from Agaricus bisporus in a gas/liquid biphasic system. The aqueous flow stream was then in-line extracted to recirculate the water medium containing the biocatalyst and the excess ascorbic acid, thus improving the cost-efficiency of the process and creating a self-sufficient closed-loop system. The organic layer was purified in-line through a catch-and-release procedure using supported boronic acid that was able to trap HTy and leave the unreacted Ty in solution. Moreover, the acetate derivatives (TyAc and HTyAc) were produced by exploiting a bioreactor packed with an immobilized acyltransferase from Mycobacterium smegmatis (MsAcT), able to selectively act on the primary alcohol. Under optimized conditions, high-value HTy was obtained in 75% yield, whereas TyAc and HTyAc were isolated in yields of up to 80% in only 10 min of residence time.

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