Optimized chemical cleaning procedure for enhancing photoemission from GaAs photocathode

2019 ◽  
Vol 91 ◽  
pp. 41-46 ◽  
Author(s):  
Cheng Feng ◽  
Yijun Zhang ◽  
Jian Liu ◽  
Yunsheng Qian ◽  
Jingzhi Zhang ◽  
...  
Keyword(s):  
Chemical Cleaning ◽  
Cleaning Procedure

Restoring Submerged UF Membrane Performance Using an Innovative Patent-Pending Chemical Cleaning Procedure

2018 ◽  
Vol 2018 (18) ◽  
pp. 197-209
Author(s):  
Gayathri Ram Mohan ◽  
Robert Harris ◽  
JC Lan ◽  
Srinivas Jalla ◽  
Jim Lozier
Keyword(s):  
Chemical Cleaning ◽  
Cleaning Procedure ◽  
Membrane Performance

scholarly journals The chemical cleaning of ceramic membrane used in UF

2012 ◽  
Vol 14 (3) ◽  
pp. 105-109 ◽  
Author(s):  
Maria Tomaszewska ◽  
Lidia Białończyk
Keyword(s):  
Food Industry ◽  
Ceramic Membrane ◽  
Fermentation Broth ◽  
Membrane Surface ◽  
Membrane Properties ◽  
Chemical Cleaning ◽  
Cleaning Procedure ◽  
Essential Step ◽  
Uf Membranes ◽  
Optimum Recovery

Ultrafiltration (UF) is one of the membrane processes which is mostly used in the dairy industry for the separation and concentration of whey components or fermentation broth. Fouling of UF membranes in the food industry is primarily due to a deposition of microorganisms, proteins, fats and minerals on the membrane surface. Thus, cleaning of the membranes is an essential step of UF separation. The results from investigations of chemical cleaning of a ceramic UF membrane fouled by precipitation of whey components and yeast contained in the fermentation broth are presented. The effect of cleaning procedure on the degree of permeability restoration by the fouled membrane was studied. The results demonstrated that a combination of sodium hydroxide, phosphoric acid and sodium hypochlorite as a disinfectant could be successfully used to achieve an optimum recovery of the membrane properties.

scholarly journals Initial Conditioning of Used Cigarette Filters for Their Recycling as Acoustical Absorber Materials

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4161
Author(s):  
Valentín Gómez Escobar ◽  
Celia Moreno González ◽  
María José Arévalo Caballero ◽  
Ana Mᵃ Gata Jaramillo
Keyword(s):  
Moisture Content ◽  
Building Construction ◽  
Chemical Cleaning ◽  
Cleaning Procedure ◽  
Cigarette Butts

Used cigarette butts represent a major and problematic form of waste, due to their abundance, toxicity, and durability. Moreover, the few proposals for their recycling are clearly insufficient, and new ones are welcome. For a new proposal regarding the reuse of used cigarette butts as acoustical absorbers in building construction, previous conditioning of the used butts is performed. This conditioning includes the elimination of moisture and toxic products accumulated in the filter of the cigarettes. Thus, in this work, the moisture content effect in acoustical absorption was analyzed, and a proposal for elimination is made. Moreover, a chemical cleaning procedure is proposed, and its influence on the acoustical behavior of the samples was also analyzed.

Silicon Surface Chemical Treatments in Oxide/Nitride Dielectric Stack Properties

2002 ◽  
Vol 716 ◽  
Author(s):  
D. Jacques ◽  
S. Petitdidier ◽  
J.L. Regolini ◽  
K. Barla
Keyword(s):  
Oxygen Content ◽  
Oxide Thickness ◽  
Morphological Data ◽  
Electrical Characteristics ◽  
Electrical Measurements ◽  
Chemical Cleaning ◽  
Force Microscopy ◽  
Chemical Treatments ◽  
Atomic Force ◽  
Interfacial Oxygen

AbstractOxide/Nitride dielectric stack is widely used as the standard dielectric for DRAM capacitors. The influence of the chemical cleaning prior to the stack formation has been studied in this work. As a result, morphological data such as stack surface roughness (Atomic Force Microscopy) and silicon nitride (SiN) incubation time for growth are comparable for all the studied cases on <Si>. However, Tof-SIMS exhibits different oxygen content at the Si/stack interface following the different chemical treatments. Electrical measurements show comparable C-V and I-V results, for the same Equivalent Oxide Thickness (same capacitance at strong accumulation i.e.-3V) while the different studied interfaces bring different interface states density with lower values for higher interfacial oxygen content. For DRAM applications, a clear improvement in electrical characteristics is obtained under low interfacial oxygen content conditions. Results are compared in embedded-DRAM cells for which we developed an industrially compatible dielectric deposition sequence to obtain minimum leakage current with maximum specific capacitance and no particular linking constraints.

The effectiveness of waist-shaped and straight-shaped interdental brushes in cleaning implant overdenture attachments: a self-controlled clinical trial

2020 ◽  
Author(s):  
Qiuwen Chen ◽  
Yanjun Ge ◽  
Jinyou Chai ◽  
Hailan Feng ◽  
Jianzhang Liu ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Oral Hygiene ◽  
Respiratory Diseases ◽  
The Other ◽  
Controlled Clinical Trial ◽  
Cleaning Procedure ◽  
Plaque Removal ◽  
Line Angle ◽  
Implant Overdenture ◽  
Interdental Brush

Elderly patients often find it challenging to remove plaque accumulated on the attachments of implant overdentures (IOD) using conventional cleaning instruments. Further, excessive plaque accumulation can lead to peri-implant diseases and occasionally to respiratory diseases. Therefore, here, we aimed to compare the effectiveness of waist-shaped interdental brushes (WIB) with that of straight-shaped ones (SIB) in plaque removal from the locator attachments of IOD. Twenty participants with two locator attachments retaining mandibular IOD participated in this study. After the baseline cleaning, the participants refrained from oral hygiene maintenance for 3 days. A dentist cleaned one of the attachments using the WIB and the other attachment using the SIB. The pre- and post-cleaning modified plaque index (mPLI) scores were recorded. Following another 3 days free from oral hygiene maintenance, the trained participants repeated the same cleaning procedure using the WIB and SIB. Pre- and post-cleaning mPLI scores were recorded. Regardless of the type of brush used, the post-cleaning mPLI scores were lower than the pre-cleaning ones. After the cleaning procedure, the overall mean mPLI score was lower in the WIB group than in the SIB group. The post-cleaning mPLI scores at the line-angles and on the axial surfaces of the attachments were also lower in the WIB group than in the SIB group. There was no difference in the cleaning effectiveness between the dentist and participants when they used the same type of interdental brush. The WIB was significantly more efficient in plaque removal than the SIB, especially at the line-angle sites.

Leakage Current Reduction of Ni-MILC Poly-Si TFT Using Chemical Cleaning Method

2018 ◽  
Vol 28 (8) ◽  
pp. 440-444
Author(s):  
Kwang-Jin Lee ◽  
◽  
Doyeon Kim ◽  
Duck-Kyun Choi ◽  
Woo-Byoung Kim
Keyword(s):  
Leakage Current ◽  
Chemical Cleaning ◽  
Cleaning Method ◽  
Current Reduction

Enhancing Efficiency of Full-Scale Ultrafiltration Membrane Treatment for Increased Capacity and Lower Operating Costs

2010 ◽  
Vol 5 (4) ◽  
Author(s):  
M.C. White PE ◽  
M.J. Kosterman
Keyword(s):  
Citric Acid ◽  
Water Treatment ◽  
Operating Costs ◽  
Percent Reduction ◽  
Chemical Cleaning ◽  
Optimization Program ◽  
Systematic Optimization ◽  
Percent Increase ◽  
Treatment Facilities ◽  
Membrane Treatment

At time of commissioning, the Racine, Wisconsin, USA ultrafiltration (UF) membrane treatment system fail short of meeting its operational goals concerning capacity and chemical cleaning intervals. The systematic optimization of this 189-million-litre-per-day (MLD) capacity UF system provided tangible operational benefits, which included a 30-percent reduction in power use, a 50-percent reduction in chlorine chemical use, a 36-percent reduction in citric acid use and a simultaneous 7-percent increase in net treatment capacity of the system. In addition, the optimization program reduced the level of buildup of foulants on the surface of the membranes. This paper summarizes the optimization procedures followed at Racine, discussing how similar measures may be applicable to other water treatment facilities.

Low-pressure membrane filtration with unconventional coagulation regimes

2005 ◽  
Vol 5 (5) ◽  
pp. 1-8 ◽  
Author(s):  
K.Y. Choi ◽  
B.A. Dempsey
Keyword(s):  
Activated Carbon ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Cross Flow ◽  
Chemical Cleaning ◽  
Sand Filters ◽  
Charge Neutralization ◽  
Floc Size ◽  
Filtration System ◽  
Pre Treatment

The objective of the research was to evaluate in-line coagulation to improve performance during ultrafiltration (UF). In-line coagulation means use of coagulants without removal of coagulated solids prior to UF. Performance was evaluated by removal of contaminants (water quality) and by resistance to filtration and recovery of flux after hydraulic or chemical cleaning (water production). We hypothesized that coagulation conditions inappropriate for conventional treatment, in particular under-dosing conditions that produce particles that neither settle nor are removed in rapid sand filters, would be effective for in-line coagulation prior to UF. A variety of pre-treatment processes for UF have been investigated including coagulation, powdered activated carbon (PAC) or granular activated carbon (GAC), adsorption on iron oxides or other pre-formed settleable solid phases, or ozonation. Coagulation pre-treatment is often used for removal of fouling substances prior to NF or RO. It has been reported that effective conventional coagulation conditions produced larger particles and this reduced fouling during membrane filtration by reducing adsorption in membrane pores, increasing cake porosity, and increasing transport of foulants away from the membrane surface. However, aggregates produced under sweep floc conditions were more compressible than for charge neutralization conditions, resulting in compaction when the membrane filtration system was pressurized. It was known that the coagulated suspension under either charge-neutralization or sweep floc condition showed similar steady-state flux under the cross-flow microfiltration mode. Another report on the concept of critical floc size suggested that flocs need to reach a certain critical size before MF, otherwise membranes can be irreversibly clogged by the coagulant solids. The authors were motivated to study the effect of various coagulation conditions on the performance of a membrane filtration system.

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