scholarly journals Characterisation of floc size, effective density and sedimentation under various flocculation mechanisms

2020 ◽  
Vol 82 (7) ◽  
pp. 1261-1271
Author(s):  
Yuping Fan ◽  
Xiaomin Ma ◽  
Xianshu Dong ◽  
Zeyu Feng ◽  
Yingdi Dong
Keyword(s):  
Settling Velocity ◽  
Structural Characteristics ◽  
Effective Density ◽  
Floc Size ◽  
Floc Structure ◽  
Trivalent Cations ◽  
Coal Tailings ◽  
Better Than ◽  
Flocculation Mechanisms

Abstract Floc structure plays an important role in the separation of coal wastewater. In this study, a camera-based method is used to evaluate quantitatively the structural characteristics of flocs generated by different coagulants and flocculants. The correlations between particle size, settlement velocity and effective density of coal tailings flocs are analysed. The results show that the statistical settling velocity increases linearly with floc size, while the effective density decreases with increase in floc size. Different flocculation mechanisms lead to diverse growth abilities of flocs. When the flocculant is used alone, the quality of the flocs generated by the flocculants, cationic polyacrylamide (CPAM) and non-ionic polyacrylamide (NPAM), is better than that generated by anionic polyacrylamide (APAM). However, the combination of trivalent cations and APAM yields a much better effect than that obtained using CPAM and NPAM. Flocs become larger and more compact when treated with a coagulant combined with a flocculant.

Characterising natural organic matter flocs

2004 ◽  
Vol 4 (4) ◽  
pp. 79-87 ◽  
Author(s):  
P. Jarvis ◽  
B. Jefferson ◽  
S.A. Parsons
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Structural Characteristics ◽  
Floc Size ◽  
Water Characteristics ◽  
Floc Structure ◽  
Floc Characteristics ◽  
Floc Strength ◽  
Settling Column ◽  
One Year

Using a dynamic optical technique and settling column apparatus, natural organic matter floc structural characteristics were monitored and evaluated over a one year period to monitor the seasonal variation in floc structure at optimum coagulation dose and pH. The results show that flocs changed seasonally with different growth rates, size, response to shear and settling rate. Autumn and summer flocs were shown to be larger and less resistant to floc breakage when compared to the other seasons, suggesting reduced floc strength. Floc strength was observed to increase with smaller median floc size. The results of the settling tests indicated that the autumnal flocs were of a more open structure which helped to explain why they settled faster. In summary, the autumnal flocs had significantly different floc characteristics although it was difficult to relate the floc structure with the incoming water characteristics.

Kepuasan Masyarakat Terhadap Pelayanan Kelurahan Setelah Pemekaran Di Tangerang Selatan

Liquidity ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 151-159
Author(s):  
Pitri Yandri
Keyword(s):  
Public Perception ◽  
Service Personnel ◽  
Urban Services ◽  
Hospitality Workers ◽  
Care Workers ◽  
Before And After ◽  
Cartesian Diagram ◽  
Better Than

The purpose of this study is (1) to analyze public perception on urban services before and after the expansion of the region, (2) analyze the level of people's satisfaction with urban services, and (3) analyze the determinants of the variables that determine what level of people's satisfaction urban services. This study concluded that first, after the expansion, the quality of urban services in South Tangerang City is better than before. Secondly, however, public satisfaction with the services only reached 48.53% (poor scale). Third, by using a Cartesian Diagram, the second priority that must be addressed are: (1) clarity of service personnel, (2) the discipline of service personnel, (3) responsibility for care workers; (4) the speed of service, (5) the ability of officers services, (6) obtain justice services, and (7) the courtesy and hospitality workers.

Structure characterization of ground calcium carbonate flocs by fractal analysis and their effects on handsheet properties

TAPPI Journal ◽  
2013 ◽  
Vol 12 (3) ◽  
pp. 17-23 ◽  
Author(s):  
WANHEE IM ◽  
HAK LAE LEE ◽  
HYE JUNG YOUN ◽  
DONGIL SEO
Keyword(s):  
Fractal Analysis ◽  
Structural Characteristics ◽  
Fractal Dimensions ◽  
Strength Loss ◽  
Structure Characterization ◽  
Uniform Size ◽  
Cross Sectional ◽  
Floc Size ◽  
Mass Fractal ◽  
Handsheet Properties

Preflocculation of filler particles before their addition to pulp stock provides the most viable and practical solution to increase filler content while minimizing strength loss. The characteristics of filler flocs, such as floc size and structure, have a strong influence on preflocculation efficiency. The influence of flocculant systems on the structural characteristics of filler flocs was examined using a mass fractal analysis method. Mass fractal dimensions of filler flocs under high shear conditions were obtained using light diffraction spectroscopy for three different flocculants. A single polymer (C-PAM), a dual cationic polymer (p-DADMAC/C-PAM) and a C-PAM/micropolymer system were used as flocculants, and their effects on handsheet properties were investigated. The C-PAM/micropolymer system gave the greatest improvement in tensile index. The mass fractal analysis showed that this can be attributed to the formation of highly dense and spherical flocs by this flocculant. A cross-sectional analysis of the handsheets showed that filler flocs with more uniform size were formed when a C-PAM/micropolymer was used. The results suggest that a better understanding of the characteristics of preflocculated fillers and their influence on the properties of paper can be gained based on a fractal analysis.

Implementasi Voip Server Berbasis IPV6 Dengan Raspberry PI

2019 ◽  
Vol 9 (01) ◽  
pp. 47-54
Author(s):  
Rabbai San Arif ◽  
Yuli Fitrisia ◽  
Agus Urip Ari Wibowo
Keyword(s):  
Internet Protocol ◽  
Wireless Transmission ◽  
Raspberry Pi ◽  
Test Results ◽  
Average Delay ◽  
Ipv6 Network ◽  
Ip Network ◽  
Selection Of ◽  
Better Than

Voice over Internet Protocol (VoIP) is a telecommunications technology that is able to pass the communication service in Internet Protocol networks so as to allow communicating between users in an IP network. However VoIP technology still has weakness in the Quality of Service (QoS). VOPI weaknesses is affected by the selection of the physical servers used. In this research, VoIP is configured on Linux operating system with Asterisk as VoIP application server and integrated on a Raspberry Pi by using wired and wireless network as the transmission medium. Because of depletion of IPv4 capacity that can be used on the network, it needs to be applied to VoIP system using the IPv6 network protocol with supports devices. The test results by using a wired transmission medium that has obtained are the average delay is 117.851 ms, jitter is 5.796 ms, packet loss is 0.38%, throughput is 962.861 kbps, 8.33% of CPU usage and 59.33% of memory usage. The analysis shows that the wired transmission media is better than the wireless transmission media and wireless-wired.

Motilitas dan Vabilitas Spermatozoa Ayam Kampung pada Suhu 5°C Menggunakan Pengencer dan Lama Simpan yang Berbeda

2018 ◽  
Vol 5 (2) ◽  
pp. 102
Author(s):  
Enike Dwi Kusumawati ◽  
Selvinus Lawu Woli ◽  
Aju Tjatur Nugroho Krisnaningsih ◽  
Waluyo Edi Susanto ◽  
Syam Rahadi
Keyword(s):  
Data Analysis ◽  
Storage Temperature ◽  
Coconut Water ◽  
Laboratory Research ◽  
Ringer Lactate ◽  
Randomized Design ◽  
Native Chicken ◽  
Lactate Solution ◽  
Better Than

ABSTRAKPenelitian ini dilakukan untuk mengetahui motilitas dan viabilitas spermatozoa ayam kampung pada suhu 5oC menggunakan pengencer dan lama simpan yang berbeda. Metode yang digunakan dalam penelitian ini adalah penelitian laboratorium menggunakan Rancangan Acak Lengkap (RAL) Faktorial dengan pengencer ringer lactat solution, air kelapa dan tanpa pengencer serta lama simpan 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, masing-masing diulang 10 kali. Variabel yang diamati yaitu motilitas dan viabilitas spermatozoa. Analisa data yang digunakan adalah analisis varian. Hasil analisis data menunjukkan bahwa motilitas dan viabilitas spermatozoa menggunakan pengencer ringer lactat solution lebih tinggi (P<0,01) serta dapat bertahan sampai lama simpan 24 jam dibandingkan air kelapa dan tanpa pengencer. Adapun nilai motilitas ringer lactat solution, air kelapa dan tanpa pengencer pada lama simpan 24 jam masing-masing sebesar 43,5±17,17%; 8±4,83%; 6,5±2,4%, sedangkan nilai viabilitasnya sebesar 83,2±7,25%; 64,6±3,20%; dan 63,1±2,33%. Kesimpulan dari hasil penelitian ini adalah ringer lactat solution lebih baik dibandingkan air kelapa dan tanpa pengencer dalam mempertahankan kualitas semen ayam kampung pada suhu simpan 5oC sampai lama simpan 24 jam.Kata Kunci : air kelapa, ayam kampung, motilitas, spermatozoa, viabilitas  ABSTRACTThis study was conducted to determine the motility and viability of spermatozoa of Native chickens at 5oC using different diluents and time storage. The method used in this study was laboratory research using Factorial Completely Randomized Design with ringer lactate solution, coconut water and without diluent at 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30 hours of time storage each repeated 10 times. The variables observed were motility and viability of sperm. Data analysis used is variance analysis. The results of data analysis showed that the motility and viability of spermatozoa using ringer lactate solution diluents was higher (P <0.05) than coconut water and without diluents. The motility values of ringer lactat solution, coconut water and without diluents were 43,5±17,17%; 8±4,83%; 6,5±2,4% respectively, while the viability values were 83,2±7,25%; 64,6±3,20% and 63,1±2,33%. The conclusion of this study is that ringer lactat solution is better than coconut water an without diluents in maintaining the quality of Native chicken semen at a storage temperature of 5oC until 24 hours.Keywords: coconut water, motility, native chicken, sperm, viability

PERBANDINGAN KUALITAS PELAYANAN ANTARA PERPUSTAKAAN PROVINSI KEPRI DENGAN KOTA TANJUNG PINANG

2017 ◽  
Vol 2 (3) ◽  
pp. 288
Author(s):  
Dimas Satriadi
Keyword(s):  
Service Quality ◽  
Public Service ◽  
Quantitative Methods ◽  
Quality Service ◽  
Data Collecting ◽  
Service Institution ◽  
Better Than

<p><em>The quality of public service is an important and it must have bye the each public service institution. Includes the library as a public service institution giving service for the all visitors. This research aims to know the comparisation of Kepri Province Libraries quality service  and Tanjungpinang City Libraries quality service. The method used in this research is quantitative methods with questionnaire to 40 responden as samples. This questionnaire as an data collecting instruments. These results indicate the quality of two libraries is good. But, if they compared the service quality of  Province Kepri  Libraries is better than  Tanjungpinang City Libraries. This look from average scored  results is 152,61 points  for Kepri Province Libraries, and 150,66 points for Tanjungpinang City Libraries, in the good categories</em></p><p>Kualitas pelayanan publik merupakan hal yang penting dan harus dimiliki oleh masing-masing lembaga pelayanan publik. Termasuk perpustakaan sebagai lembaga pelayanan publik yang memberikan pelayanan kepada semua pengunjung. Penelitian ini bertujuan untuk mengetahui perbandingan kualitas layanan Perpustakaan Provinsi Kepri dan kualitas pelayanan Perpustakaan Kota Tanjungpinang. Metode yang digunakan dalam penelitian ini adalah metode kuantitatif dengan 40 responden sebagai sampel. Kuesioner ini sebagai alat pengumpul data. Hasil penelitian ini menunjukkan kualitas kedua perpustakaan suda bagus. Tapi jika dibandingkan kualitas pelayanan Perpustakaan Provinsi Kepri lebih baik dari pada Perpustakaan Kota Tanjungpinang. Hasil dari hasil rata-rata ini adalah 152,61 poin untuk Perpustakaan Kepri Province, dan 150,66 poin untuk Perpustakaan Kota Tanjungpinang, dalam kategori baik.</p><p><em><br /></em></p>

scholarly journals Performance Evaluation of IMERG GPM Products during Tropical Storm Imelda

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 687
Author(s):  
Salman Sakib ◽  
Dawit Ghebreyesus ◽  
Hatim O. Sharif
Keyword(s):  
Stage Iv ◽  
Tropical Storm ◽  
Average Correlation ◽  
Acceptable Range ◽  
Precipitation Estimates ◽  
Overall Performance ◽  
Early Late ◽  
Statistical Metrics ◽  
Better Than

Tropical Storm Imelda struck the southeast coastal regions of Texas from 17–19 September, 2019, and delivered precipitation above 500 mm over about 6000 km2. The performance of the three IMERG (Early-, Late-, and Final-run) GPM satellite-based precipitation products was evaluated against Stage-IV radar precipitation estimates. Basic and probabilistic statistical metrics, such as CC, RSME, RBIAS, POD, FAR, CSI, and PSS were employed to assess the performance of the IMERG products. The products captured the event adequately, with a fairly high POD value of 0.9. The best product (Early-run) showed an average correlation coefficient of 0.60. The algorithm used to produce the Final-run improved the quality of the data by removing systematic errors that occurred in the near-real-time products. Less than 5 mm RMSE error was experienced in over three-quarters (ranging from 73% to 76%) of the area by all three IMERG products in estimating the Tropical Storm Imelda. The Early-run product showed a much better RBIAS relatively to the Final-run product. The overall performance was poor, as areas with an acceptable range of RBIAS (i.e., between −10% and 10%) in all the three IMERG products were only 16% to 17% of the total area. Overall, the Early-run product was found to be better than Late- and Final-run.

scholarly journals Being a Gambler during the COVID-19 Pandemic: A Study with Italian Patients and the Effects of Reduced Exposition

2021 ◽  
Vol 18 (2) ◽  
pp. 424
Author(s):  
Maria Anna Donati ◽  
Silvia Cabrini ◽  
Daniela Capitanucci ◽  
Caterina Primi ◽  
Roberta Smaniotto ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Gambling Behavior ◽  
Online Gambling ◽  
Problem Gamblers ◽  
Electronic Gambling Machines ◽  
Electronic Gambling ◽  
Gambling Market ◽  
The Impact ◽  
Gambling Activities

The COVID-19 pandemic, with the consequent lockdown of about 3 months, can be viewed as an experimental model to observe the impact of the depletion of environmental factors that stimulate gambling, particularly electronic gambling machines (EGMs) that were set to zero. The effects of some structural characteristics of gambling activities that increase gambling behavior were studied among disordered gamblers in treatment in this unique scenario. In fact, studies investigating the effects of the lockdown on problem gamblers (PGs) under treatment are missing. The aims of this study were to analyze patients’ gambling behavior and craving during the lockdown and to conduct a comparison between gambling disorder (GD) symptoms at the beginning of the treatment and during lockdown. The study was conducted in Italy, the European country with the largest gambling market and the first to be affected by the virus. Data were collected through a semi-structured telephone interview conducted by healthcare professionals. Participants were 135 PGs under treatment (109 males, mean age = 50.07). Results showed that most PGs achieved a significant improvement in their quality of life, with less gambling behavior, GD symptoms, and lower craving. No shift toward online gambling and very limited shift towards other potential addictive and excessive behaviors occurred. The longer the treatment, the more monitoring is present and the better the results in terms of symptoms reduction. Individual and environmental characteristics during the lockdown favored the reduction in symptoms. Consideration for prevention and treatment are discussed.

A new approach based on graph matching and evolutionary approach for sport scheduling problem

2020 ◽  
pp. 1-16
Author(s):  
Meriem Khelifa ◽  
Dalila Boughaci ◽  
Esma Aïmeur
Keyword(s):  
Graph Matching ◽  
State Of The Art ◽  
Travel Cost ◽  
Round Robin ◽  
New Approach ◽  
Traveling Tournament Problem ◽  
Significant Interest ◽  
National League ◽  
Better Than

The Traveling Tournament Problem (TTP) is concerned with finding a double round-robin tournament schedule that minimizes the total distances traveled by the teams. It has attracted significant interest recently since a favorable TTP schedule can result in significant savings for the league. This paper proposes an original evolutionary algorithm for TTP. We first propose a quick and effective constructive algorithm to construct a Double Round Robin Tournament (DRRT) schedule with low travel cost. We then describe an enhanced genetic algorithm with a new crossover operator to improve the travel cost of the generated schedules. A new heuristic for ordering efficiently the scheduled rounds is also proposed. The latter leads to significant enhancement in the quality of the schedules. The overall method is evaluated on publicly available standard benchmarks and compared with other techniques for TTP and UTTP (Unconstrained Traveling Tournament Problem). The computational experiment shows that the proposed approach could build very good solutions comparable to other state-of-the-art approaches or better than the current best solutions on UTTP. Further, our method provides new valuable solutions to some unsolved UTTP instances and outperforms prior methods for all US National League (NL) instances.

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