Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Muhammad, Ali" wg kryterium: Autor

  Lista filtrów
Wyrównaj
Wyświetlanie 1-25 z 40
Tytuł:
On inclusion relationships of certain subclasses of meromorphic functions involving integral operator
Autorzy:
Muhammad, Ali
Powiązania:
https://bibliotekanauki.pl/articles/747194.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
Meromorphic functions
functions with bounded boundary and bounded radius rotation
quasi-convex functions
close-to-convex functions
generalized hypergeometric functions
functions with positive real part
Hadamard product (or convolution)
Opis:
In this paper, we introduce some subclasses of meromorphic functions in the punctured unit disc. Several inclusion relationships and some other interesting properties of these classes are discussed.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica; 2012, 66, 1
0365-1029
2083-7402
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Probing 3D chaotic Thomas’ cyclically attractor with multimedia encryption and electronic circuitry
Autorzy:
Khan, NajeebAlam
Qureshi, Muhammad Ali
Akbar, Saeed
Ara, Asmat
Powiązania:
https://bibliotekanauki.pl/articles/27312000.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Thomas’ cyclically attractor
fractional calculus
chaos
encryption
Opis:
This study investigates Thomas’ cyclically symmetric attractor dynamics with mathematical and electronic simulations using a proportional fractional derivative to comprehend the dynamics of a given chaotic system. The three-dimensional chaotic flow was examined in detail with Riemann-Liouville derivative for different values of the fractional index to highlight the sensitivity of chaotic systems with initial conditions. Thus, the dynamics of the fractional index system were investigated with Eigenvalues, Kaplan-Yorke dimension, Lyapunov exponent, and NIST testing, and their corresponding trajectories were visualized with phase portraits, 2D density plot, and Poincaré maps. After obtaining the results, we found that the integer index dynamics are more complex than the fractional index dynamics. Furthermore, the chaotic system circuit is simulated with operational amplifiers for different fractional indices to generate analog signals of the symmetric attractor, making it an important aspect of engineering. The qualitative application of our nonlinear chaotic system is then applied to encrypt different data types such as voice, image, and video, to ensure that the developed nonlinear chaotic system can widely applied in the field of cyber security.
Źródło:
Archives of Control Sciences; 2023, 33, 1; 239--271
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and activity evaluation of Ce-Mn-Cu mixed oxide catalyst for selective oxidation of co in automobile engine exhaust: effect of Ce/Mn loading content on catalytic activity
Autorzy:
Bilal, Yasir
Nasir, Muhammad Ali
Nasreen, Sadia
Akhter, Niaz Ahmed
Pasha, Riffat Asim
Noor, Muhammad Farhan
Powiązania:
https://bibliotekanauki.pl/articles/101992.pdf
Data publikacji:
2018
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
base metal oxide catalyst
catalytic converter
CO sensor
CO-precipitation
catalytic activity
katalizator tlenku metalu zasadowego
katalizator
czujnik CO
strącanie CO
aktywność katalityczna
Opis:
A series of Mn-doped CeO2-CuO catalyst (CeO2-MnOx-CuO) (Ce/Mn molar ratio of 0.5, 1.0 2.0 and 3.0) were prepared using co-precipitation method for the selective oxidation of CO in automobile engine exhaust. The content of copper was 5.0 wt. % in each sample. Catalysts were installed on the automobile engine exhaust and CO amount was recorded with help of CO sensor, with and without the catalyst. The catalytic converter efficiency was estimated for each catalyst through efficiency formula. It was observed that Ce/Mn catalyst with a molar ratio of 2.0 shows the maximum efficiency (88.35%). Stability of conversion process was analyzed by plotting the CO amount with respect to time. The catalyst with Ce/Mn molar ratio of 2.0 performed the most streamline conversion process with least deviations.
Źródło:
Advances in Science and Technology. Research Journal; 2018, 12, 1; 260-266
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modification of bentonite nanoclay for textile application
Modyfikacja nano bentonitu do zastosowań włókienniczych
Autorzy:
Amir, Muhammad
Hasany, Syed Farhan
Asghar, Muhammad Sajid Ali
Powiązania:
https://bibliotekanauki.pl/articles/24202774.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
bentonite
textile fabrics
mechanical properties
bentonit
tekstylia
właściwości mechaniczne
Opis:
The influence of the bentonite content (1, 3, 5 wt%) on the mechanical properties of lightweight cotton (C), polyester (P) and polyester-cotton (P/C 50/50) fabrics was investigated. Starch was used as a water-insoluble binder for coating fabrics. Bentonite nanoparticles were obtained by repeated hydration, decantation and evaporation of the water dispersion. The bentonite particle size was determined by the XRD method using the Debye-Scherrer equation. The diffraction of the laser beam was used to determine particles size distribution. The addition of bentonite nanoclay significantly improved tensile strength (26-61% and 99–118% in the warp and weft direction, respectively) and tear strength (4‒13% and 5–24% in the wrap and weft direction, respectively) of coated fabrics. Their abrasion resistance has also slightly increased. The biggest changes were noted for the cotton fabric, the smallest for the polyester fabric, which may result from the low compatibility between starch and the polyester fabric.
Zbadano wpływ zawartości bentonitu (1, 3, 5% mas.) na właściwości mechaniczne lekkich tkanin bawełnianych (C), poliestrowych (P) i poliestrowo-bawełnianych (P/C 50/50). Jako nie-rozpuszczalny w wodzie środek wiążący do powlekania tkanin zastosowano skrobię. Nanocząstki bentonitu otrzymywano poprzez kilkukrotną hydratację, dekantację i odparowanie dyspersji wodnej. Wielkość cząstek bentonitu oznaczono metodą XRD, stosując równanie Debye-Scherrera. Dyfrakcja wiązki laserowej posłużyła do określenia rozkładu wielkości cząstek. Zastosowanie nanoglinki bentonitowej wpłynęło na istotną poprawę wytrzymałości na rozciąganie (o 26‒61% w kierunku osnowy i 99‒118% w kierunku wątku) oraz rozdzieranie (4‒13% w kierunku osnowy i 5‒24% w kierunku wątku) powlekanych tkanin. Nieznacznie zwiększyła się również ich odporność na ścieranie. Największe zmiany zanotowano w przypadku tkaniny bawełnianej, najmniejsze dla tkaniny poliestrowej, co może wynikać z małej kompatybilności między skrobią a tkaniną poliestrową.
Źródło:
Polimery; 2023, 68, 2; 79--85
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hematological Performance and Survival of Common Carp (Cyprinus carpio Linnaeus, 1758) Strain Majalaya Fingerlings Against Temperature Stress
Autorzy:
Yustiati, Ayi
Saefulhadjar, Sadra Muhammad Haydar Ali
Suryadi, Ibnu Bangkit Bioshina
Iskandar, Iskandar
Powiązania:
https://bibliotekanauki.pl/articles/1031780.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Aeromonas hydrophila
C. c. haematopterus
Common carp Strain Majalaya
Cyprinus carpio
maintenance temperature
number of erythrocytes
number of leukocytes
survival rate
Opis:
The research was conducted at the Aquaculture Laboratory of the Faculty of Fisheries and Marine Science, Universitas Padjadjaran, Jatinangor. The purpose of this research is to determine the optimum temperature for the maintenance of Common carp strain Majalaya fingerlings based on resistance to temperature stress that is known through their blood profile and survival rate. Common carp strain Majalaya fingerlings originating from Ciparay, West Java. Total body length is 8-12 cm with a minimum weight of 10 g. The method used is experimental with a completely randomized design (CRD) consisting of three treatments and five replications. The fish are kept at 24 ºC (control without heater), 29 ºC and 34 ºC. Each experimental unit contains 10 fishes. The results obtained by the survival rate (SR) of Common carp strain Majalaya which were maintained at a treatment temperature of 24 ºC by 100%, the 29 ºC by 70%, the 34 ºC by only 42% remained on the 21st day. The number of erythrocytes of common carp strain Majalaya fingerlings before the treatment temperature was 2.77 × 106 cells/mm3. The average number of erythrocytes of the 24ºC treatment from 7th, 14th and 21st day were 2.82, 2.82 and 2.81 × 106 cells/mm3; the 29 ºC were 2.93, 2.68 and 2.42 × 106 cells/mm3; the 34 ºC were 3.08, 2.52 and 1.99 × 106 cells/mm3. While the number of leukocytes of common carp strain Majalaya fingerlings before the treatment temperature was 13.61 × 104 cells/mm3. The average number of leukocytes of the 24 ºC treatment from 7th, 14th and 21st day were 13.73, 13.71 and 13.88 × 104 cells/mm3; the 29 ºC were 18.40, 16.46 and 15.76 × 104 cells/mm3; the 34 ºC were 20.78, 18.46 and 16.81 × 104 cells/mm3.
Źródło:
World Scientific News; 2020, 150; 92-104
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of potential groundwater recharge sites in a semi-arid region of Pakistan using Saaty’s Analytical Hierarchical Process (AHP)
Autorzy:
Suliman, Muhammad
Samiullah, Khan
Ali, Muhammad
Powiązania:
https://bibliotekanauki.pl/articles/2055773.pdf
Data publikacji:
2022
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
Saaty’s Analytical Hierarchical Process (AHP)
weighted overlay analysis
semi-arid region
groundwater potential sites
GIS and remote sensing
Opis:
Groundwater is a precious source of fresh water and a major component of the entire water supply. Both water quality and quantity could be satisfied by evaluating the groundwater potential sites (GWPS). This paper analyzes the ground-water potentials in a semi-arid region of Khyber Pakhtunkhwa, Pakistan. It describes a standard methodology to identify and map GWPS using integrated Geographical Information System (GIS) and remote sensing (RS) methods. Eight parameters including elevation, slope, drainage density, lineaments density, soil, geology, land use/land cover and rainfall were integrated to explore areas with groundwater holding capability. GWPS were delineated through subjective weights assigned after coupling various thematic layers using Saaty’s Analytical Hierarchical Process (AHP). The modelled GWPS were cross-checked with tube wells data. The result indicates that the central part of the study area has good potential for groundwater reserves/exploitation, where the factors i.e. moderate to high drainage density, sedimentary sequence of alluvial plain, low elevation etc. discern the central portion of the study area as a suitable site for groundwater. This study suggests that the applied method proves to be very significant and reliable tool for timely assessment of quality assured evaluation of groundwater resources. This study could be a systematic guide for future investigations for water related explorations, especially in semi-arid environments.
Źródło:
Geomatics and Environmental Engineering; 2022, 16, 1; 53--70
1898-1135
Pojawia się w:
Geomatics and Environmental Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mode-route choice decisions: a case study of CPEC investment in Pakistan railways
Autorzy:
Ali, Yousaf
Sabir, Muhammad
Powiązania:
https://bibliotekanauki.pl/articles/2173449.pdf
Data publikacji:
2022
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
AHP-TOPSIS
hybrid-CDM
route-mode choice
wybór trybu pracy
Opis:
. This study proposes the use of multi-criteria decision models (MCDM) for transportation mode-route choice decisions. This method is beneficial when trips' microdata are unavailable. Route-mode choice decisions were investigated for three public transportation modes (buses, railways, and airlines) in the post-China Pakistan Economic Corridor (CPEC) investment in Pakistan Railways (PR) for a link between Peshawar and Karachi. TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) was used for the mode choice decisions and a hybrid model of AHP (Analytical Hierarchy Approach) – TOPSIS was used for the route choice decision ML-1 link of PR. This study concludes that rails were the best mode of transportation in post-CPEC investment. Furthermore, route 3, linking Karachi to Peshawar via Lodhran, Multan, and Miniawali, is the best route connection among the four considered routes.
Źródło:
Zeszyty Naukowe. Transport / Politechnika Śląska; 2022, 115; 5--21
0209-3324
2450-1549
Pojawia się w:
Zeszyty Naukowe. Transport / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deep Neural Network for Supervised Single-Channel Speech Enhancement
Autorzy:
Saleem, Nasir
Irfan Khattak, Muhammad
Ali, Muhammad Yousaf
Shafi, Muhammad
Powiązania:
https://bibliotekanauki.pl/articles/177497.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
deep neural network
intelligibility
speech enhancement
speech quality
supervised learning
Wiener filtering
Opis:
Speech enhancement is fundamental for various real time speech applications and it is a challenging task in the case of a single channel because practically only one data channel is available. We have proposed a supervised single channel speech enhancement algorithm in this paper based on a deep neural network (DNN) and less aggressive Wiener filtering as additional DNN layer. During the training stage the network learns and predicts the magnitude spectrums of the clean and noise signals from input noisy speech acoustic features. Relative spectral transform-perceptual linear prediction (RASTA-PLP) is used in the proposed method to extract the acoustic features at the frame level. Autoregressive moving average (ARMA) filter is applied to smooth the temporal curves of extracted features. The trained network predicts the coefficients to construct a ratio mask based on mean square error (MSE) objective cost function. The less aggressive Wiener filter is placed as an additional layer on the top of a DNN to produce an enhanced magnitude spectrum. Finally, the noisy speech phase is used to reconstruct the enhanced speech. The experimental results demonstrate that the proposed DNN framework with less aggressive Wiener filtering outperforms the competing speech enhancement methods in terms of the speech quality and intelligibility.
Źródło:
Archives of Acoustics; 2019, 44, 1; 3-12
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The power of ADKAR change model in innovative technology acceptance under the moderating effect of culture and open innovation
Autorzy:
Ali, Muhammad Ahmad
Zafar, Usman
Mahmood, Asif
Nazim, Muhammad
Powiązania:
https://bibliotekanauki.pl/articles/2021479.pdf
Data publikacji:
2021
Wydawca:
Wyższa Szkoła Logistyki
Tematy:
ADKAR change model
reinforcement
uncertainty avoidance
perceived ease of use
inbound and outbound open innovation
perceived usefulness
model ADKAR
wzmocnienie
unikanie niepewności
łatwość użytkowania
Opis:
Background: Continuous change is a vital factor for organization’s sustainable growth and success. The implementation of modern information technology in business has become a core need of the hour. This study endeavours to answer how to cope with resistance to change when implementing new technology in the banking sector. A theoretical model has been developed with the blend of ADKAR change model, Technology Acceptance Model (TAM), and Hofstede dimensions of national culture to investigate the impact of the ADKAR change model on Technology Acceptance under the moderation of two national culture’s dimensions. Materials and Methods: In order to collect data, 500 self-administered questionnaires were dropped personally in five major banks of five cities of Pakistan using the convenience-based employee intercept sampling technique. The validated response rate was 68% by having 340 fit questionnaires for analysis using covariance-based structure equation modelling with the help of SmartPLS. Results: The results uncover the significant existence of covariance between dimensions of the ADKAR change model and technology acceptance model. The findings are statistically significant, inferring the influential role of change management on technology adoption. Conclusion: The study results provide promising implications based on these conclusions and findings for both theoretical aspects of these different models and practitioners.
Źródło:
LogForum; 2021, 17, 4; 485--502
1734-459X
Pojawia się w:
LogForum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Control of optical chaos spectrum in semiconductor laser for secure RoF communication
Autorzy:
Mazhar, Danish Ali
Ali, Syed Zafar
Islam, Muhammad Khawar
Powiązania:
https://bibliotekanauki.pl/articles/2172849.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
chaos
radio over fiber
secure optical communication
Opis:
A critical requirement in optical chaos based secure radio over fiber (RoF) system design is the ability to control center frequency, spectral bandwidth, power level and signature of chaos to submerge message with sufficient horizontal and vertical margins both in time and frequency domains. Once frequency domain masking is completely achieved, time domain masking is met automatically, the former being more stringent. In a direct modulated semiconductor laser, the three control parameters are bias current (Ibias), modulation current (Imod) and modulation frequency (ωa). It is found that Imod increases bandwidth and amplitude dynamic range of chaotic pulses. Ibias increases the cavity power and hence average peak amplitude of laser chaotic pulses. The modulation frequency increases the speed of overall cavity dynamics and hence is used to increase the bandwidth of chaos but a corresponding increase in bias and modulation currents is required to support high repetition pulses. The results show relationship between three control parameters (bias current, modulation current and modulation frequency) in a direct modulated semiconductor laser and optical chaos bandwidth using regression.
Źródło:
Optica Applicata; 2022, 52, 4; 485--495
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parallelizing user-defined functions in the ETL workflow using orchestration style sheets
Autorzy:
Ali, Syed Muhammad Fawad
Mey, Johannes
Thiele, Maik
Powiązania:
https://bibliotekanauki.pl/articles/331096.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
ETL workflow
parallel ETL operator
parallel algorithmic skeleton
user defined function
workflow ETL
równoległy szkielet algorytmiczny
funkcja zdefiniowana przez użytkownika
Opis:
Today’s ETL tools provide capabilities to develop custom code as user-defined functions (UDFs) to extend the expressiveness of the standard ETL operators. However, while this allows us to easily add new functionalities, it also comes with the risk that the custom code is not intended to be optimized, e.g., by parallelism, and for this reason, it performs poorly for data-intensive ETL workflows. In this paper we present a novel framework, which allows the ETL developer to choose a design pattern in order to write parallelizable code and generates a configuration for the UDFs to be executed in a distributed environment. This enables ETL developers with minimum expertise in distributed and parallel computing to develop UDFs without taking care of parallelization configurations and complexities. We perform experiments on large-scale datasets based on TPC-DS and BigBench. The results show that our approach significantly reduces the effort of ETL developers and at the same time generates efficient parallel configurations to support complex and data-intensive ETL tasks.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2019, 29, 1; 69-79
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detection and enumeration of Enteric bacteria associated with food handlers and surfaces of food manufacturing industry located in Hub city, Pakistan
Autorzy:
Ali, Razim
Hayat, Amir
Fatima, Madiha
Noman, Muhammad
Powiązania:
https://bibliotekanauki.pl/articles/1182928.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
enterobacteriaceae
foodborne microbes
hygiene
surface contamination
food handlers
e. coli
sanitation
Opis:
Foodborne microorganisms harbor and adheres itself to the food material and surrounding surfaces for a long time and influence the food quality and consumers health. Among these microbes the presence of Enteric indicator bacteria in food premises confers the indication of entero-pathogens, i.e. E. coli, Salmonella, Shigella and Campylobacters that could cause severe systemic infections in consumers. In this study, the hygienic status of confectionery and supplementary food processing facility was evaluated. A total of 10497 examinations were performed on 3499 swab samples collected from food premises and handlers for the analysis of Enteric indicator bacteria. From swabs, 1277 (12.2%) isolates were identified in which Enterobacteriaceae were found with higher frequency 604 (47.3%) followed by Coliforms 293 (30.8%) and Escherichia coli 280 (21.9%) respectively. The mean count (CFU/cm2) was found maximum for plain surfaces (floors, walls and door), while the lowest was for equipment and machinery. Overall isolates percent prevalence was determined where Enterobacteriaceae were 47%, Coliforms 31% and Escherichia coli 22%. Majority of the floor surfaces were highly contaminated, where washing and sanitation practices were observed to be inappropriate. Worker hygiene status was lacking essential food safety and hygiene standards. In general, the Enteric bacteria were found with higher ratio, that could affect the food quality and quantity both to a greater extent with some influences on consumers health.
Źródło:
World Scientific News; 2016, 49, 2; 192-203
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radiation induced degradation of Congo red dye: a mechanistic study
Autorzy:
Muner, Majid
Saeed, Muhammad
Bhatti, Ijaz Ahmad
Haq, Atta-ul
Khosa, Muhammad Kaleem
Jamal, Muhammad Asghar
Ali, Saddaqat
Powiązania:
https://bibliotekanauki.pl/articles/146490.pdf
Data publikacji:
2019
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
Congo red
radiolytic product
irradiation
advanced oxidation process
Opis:
Synthetic dyes are persistent pollutants with poor biodegradability. The present study is about the degradation of direct Congo red dye in aqueous media using the Co-60 gamma radiation source. The experimental conditions such as gamma-ray absorbed doses, amount of oxidant (H2O2) and pH conditions were evaluated. The lambda max of dye solution was noted as 498 nm, and then, decrease in absorbance and reduction in chemical oxygen demand (COD) were examined. The complete colour removal of dye was observed at 5 kGy, while a signifi cant COD removal was observed at 15 kGy gamma-ray absorbed dose in conjunction with oxidant for 50 mg/L concentration. It was found that pH has no influence on degradation efficiency. A possible degradation pathway was proposed. The radiolytic end products were monitored by Fourier transform infrared (FTIR) and gas chromatography coupled with mass spectrometry (GC-MS) to explore the degradation mechanism. It was imperative to study the oxidative degradation pathway to provide directions for potential applicability of advanced oxidation process (AOP) in industrial wastewater treatment.
Źródło:
Nukleonika; 2019, 64, 2; 49-53
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observer design estimating the propofol concentration in PKPD model with feedback control of anesthesia administration
Autorzy:
Ilyas, Muhammad
Khan, Awais
Khan, Muhammad Abbas
Xie, Wei
Riaz, Raja Ali
Khan, Yousaf
Powiązania:
https://bibliotekanauki.pl/articles/2106507.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pharmacokinetic models
pharmacodynamic model
bispectral index monitor
observer design
sliding mode control
Opis:
Propofol infusion in anesthesia administration requires continual adjustment in the manual infusion system to regulate the hypnosis level. Hypnotic level is based on Bispectral Index Monitor (BIS) showing the cortical activity of the brain scaled between 0 to 100. The new challenging aspect of automation in anaesthesia is to estimate the concentration of hypnotic drugs in different compartments of the body including primary, rapid peripheral (muscle), slow peripheral (bones, fat) and effect site (brain) compartment based on Pharmacokinetics (PK) and Pharmacodynamics (PD) model. This paper aimed to regulate the hypnosis level with estimating the Propofol concentrations using a linear observer in feedback control strategy based on Integral Super-Twisting Sliding Mode Controller (ISTSMC). The drug concentration in plasma of the silico patients accurately estimated in nominal transient. The results show that tracking errors between the actual output in form of BIS level and linearized output nearly approaches to zero in the maintenance phase of anesthesia to ensure the controller response on sliding phase with optimum performances by achieving desired hypnotic level 50 on BIS. The robustness of control strategy is further ensured by adding measurement noise of electromagnetic environment of operation theatre distracting signal quality index of the output BIS level.
Źródło:
Archives of Control Sciences; 2022, 32, 1; 85--103
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bayesian estimation of a geometric distribution using informative priors based on a Type-I censoring scheme
Autorzy:
Akhtar, Nadeem
Khan, Sajjad Ahamad
Amin, Muhammad
Khan, Akbar Ali
Ali, Amjad
Manzoor, Sadaf
Powiązania:
https://bibliotekanauki.pl/articles/20311948.pdf
Data publikacji:
2023-06-13
Wydawca:
Główny Urząd Statystyczny
Tematy:
prior distribution
posterior distribution
geometric distribution
beta distribution
Kumraswamy distribution
Opis:
In this paper, the geometric distribution parameter is estimated under a type-I censoring scheme by means of the Bayesian estimation approach. The Beta and Kumaraswamy informative priors, as well as five loss functions are used for this purpose. Expressions of Bayes estimators and Bayes risks are derived under the Squared Error Loss Function (SELF), the Quadratic Loss Function (QLF), the Precautionary Loss Function (PLF), the Simple Asymmetric Precautionary Loss Function (SAPLF), and the DeGroot Loss Function (DLF) using the two aforementioned priors. The prior densities are obtained through prior predictive distributions. Simulation studies are carried out to make comparisons using Bayes risks. Finally, a real-life data example is used to verify the model’s efficiency.
Źródło:
Statistics in Transition new series; 2023, 24, 3; 257-263
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of LMX as Mediator in Procedural Justice – Organizational Citizenship Behavior Relationship
Autorzy:
Ishaq, Muhammad Ishtiaq
Nazia, Munazer Hussain
Nawaz, Muhammad Musarrat
Asim, Ali Ijaz
Cheema, Luqman J.
Powiązania:
https://bibliotekanauki.pl/articles/45636411.pdf
Data publikacji:
2012-09-30
Wydawca:
Wydawnictwo Adam Marszałek
Tematy:
faculty
higher education
LMX
OCB
Pakistan
procedural justice
universities
Opis:
Scant literature is available on procedural justice – organizational citizenship behaviour (OCB) via mediating role of leader-member exchange (LMX) in higher education context especially in Asian countries like Pakistan. For this purpose, data was collected from 452 permanent and contractual teaching faculty serving in different positions at private and public sector degree awarding institutes / universities accredited by the Higher Education Commission (HEC) of Pakistan. Mediated regression analysis, as proposed by Baron and Kenny (1986), was employed to address the research hypothesis. Results showed that LMX fully mediates the relationship of procedural justice OCB. Implications for future researchers and academic administrators are presented.
Źródło:
The New Educational Review; 2012, 29; 202-211
1732-6729
Pojawia się w:
The New Educational Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Holistic human resource development model in health sector : a phenomenological approach
Holistyczny model rozwoju zasobów ludzkich w sektorze zdrowia : podejście fenomenologiczne
Autorzy:
Arshad, Mohd Anuar
Shabbir, Muhammad Salman
Mahmood, Arshad
Sulaiman, Mohammed Ali Bait Ali
Khan, Shahid
Powiązania:
https://bibliotekanauki.pl/articles/405991.pdf
Data publikacji:
2019
Wydawca:
Politechnika Częstochowska
Tematy:
spiritual quotient
human resource development
HRD
phenomenological approach
iloraz duchowy
rozwój zasobów ludzkich
podejście fenomenologiczne
Opis:
This study proposed holistic human resource development model in health sector. This study focused on human resources (HR) managers and the top management of the health sector in Pakistan. Using a qualitative methodology, the researcher focused on the selected phenomenological method. In this study, primary data collection was conducted through personal interviews with human resource managers and the top management of three health organizations in Pakistan. With regard to the sampling technique, the study would be based on a specific sampling. This article presents the results of the three research objectives. The first research objective examines the development and implementation process of the human resource development model in organizations. Second, intelligence quotient and emotion quotient programs are defined by organizations within the current human resource development models. Third, this study examines the organization's understanding of spiritual quotient and evaluates awareness of the importance of spiritual quotient for the development of human resource development model. It suggests that spiritual quotient is an important part of organizational development.
W badaniu zaproponowano holistyczny model rozwoju zasobów ludzkich w sektorze opieki zdrowotnej. To badanie koncentrowało się na menedżerach ds. Zasobów ludzkich (HR) i najwyższym kierownictwie sektora opieki zdrowotnej w Pakistanie. Korzystając z metodologii jakościowej, badacz skoncentrował się na wybranej metodzie fenomenologicznej. W tym badaniu gromadzono dane pierwotne w drodze wywiadów osobistych z menedżerami ds. Zasobów ludzkich i najwyższym kierownictwem trzech organizacji zdrowotnych w Pakistanie. W odniesieniu do techniki pobierania próbek badanie opierałoby się na konkretnym pobieraniu próbek. W tym artykule przedstawiono wyniki trzech celów badawczych. Pierwszy cel badawczy dotyczy procesu opracowywania i wdrażania modelu rozwoju zasobów ludzkich w organizacjach. Po drugie, iloraz inteligencji i iloraz emocji są definiowane przez organizacje w ramach obecnych modeli rozwoju zasobów ludzkich. Po trzecie, badanie to bada zrozumienie ilorazu duchowego przez organizację i ocenia świadomość znaczenia ilorazu duchowego dla rozwoju modelu rozwoju zasobów ludzkich. Sugeruje, że iloraz duchowy jest ważną częścią rozwoju organizacji.
Źródło:
Polish Journal of Management Studies; 2019, 20, 1; 44-53
2081-7452
Pojawia się w:
Polish Journal of Management Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of safety climate on job performance and job satisfaction with moderating role of psychological capital
Autorzy:
Kiyani, Amir Saif Ali
Rizvi, Tahir Hussain
Khan, Muhammad Saqib
Powiązania:
https://bibliotekanauki.pl/articles/1375509.pdf
Data publikacji:
2019
Wydawca:
Międzynarodowy Instytut Innowacji Nauka – Edukacja – Rozwój w Warszawie
Tematy:
Safety climate
Job Satisfaction
Job Performance
psychological Capital
Conserva-tion of Resource Theory
Public Sector Organization Rawalpindi and Islamabad
Opis:
The current research investigated the effect of safety climate on job satisfaction and job performance with psychological capital as a moderator between safety climate and job satisfaction as well as job performance. This research fills the gap by collecting empirical evidence from the emerging organizations of Pakistan. Conservation of resource theory (COR) is relevant to the research area. Data were collected from 300 employees from different Organizations. The current study is empirical and quantitative-based study is used to conducted research. Data were collected by convenient non-probability sampling techniques to be used and collected from employees working in the reputed organization; Chemical, Cement, Petroleum, Oil and Gas industry of Islamabad and Rawalpindi. Confirmatory Factor analysis was done through AMOS and hypotheses were tested through SPSS regression analysis process of Hayes model. To test the moderation effects, the process of Hayes model 1 was also performed. Safety climate has a positive relationship with the two DVs which are job performance and job satisfaction. Moreover, Psychological Capital played a significant moderating role between safety climate and job satisfaction as well as job performance. When Psychological capital was high, the relationship between safety climate and job performance as well as the relationship between safety climate and job satisfaction were stronger. These results are important for future studies. This research recommended top management and responsible authorities to promote safety climate activates between their organization in order to enhance their employees satisfy and high performed. Moreover, this research strongly recommends psychological capital amongst organization looking for highly satisfied and effective employees. Further implications for practice were discussed in detail.
Źródło:
International Journal of New Economics and Social Sciences; 2019, 9(1); 363-379
2450-2146
2451-1064
Pojawia się w:
International Journal of New Economics and Social Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conversion of cleaned Oltu-stone wastes (a semi-precious stone) into a valuable product using binderless agglomeration
Autorzy:
Bawani, Muhammad Raheel
Arol, Ali İhsan
Tozsin, Gulsen
Torun, Abdulvahit
Powiązania:
https://bibliotekanauki.pl/articles/24148662.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
agglomeration
cleaned Oltu-stone waste
pressed Oltu-stone
aliphatic carbon
Opis:
Oltu-stone, a semi-precious stone found in Erzurum's Oltu area, is commonly utilized in the creation of decorative ornaments. More than 90% of the Oltu-stone mined is classified as Oltu-stone waste, consisting of poor Oltu-stone due to mineral impurities and small fragment sizes (OW). This waste is thrown or burnt, resulting in financial losses. Such losses might be reduced by using Oltu-stone waste (OW) instead of standard Oltu-stone (SO). The purpose of this study was to convert Oltu-stone waste into a useful pressed product. It was cleaned using the float-sink method with a density of 1.25 g.cm-3 and then utilized for binderless high-pressure agglomeration to create pressed Oltu-stone. The physical, mechanical, microscopic, and spectroscopic characteristics of the material were investigated. The bulk density of pressed Oltu-stone was reported to be 1.22-1.26 g.cm-3. However, with the same pressing time, indirect tensile strength was identical and varied when the pressing time was changed. The surface morphology of the crushed Oltu-stone revealed that it was more intact and had a less porous structure. Oltu-stone includes a lot of volatile matter and aliphatic carbon structures because of its high liptinite content. An FTIR investigation revealed that altering the pressing time affects the chemical structure but not the pressure. This effect was seen in molecules containing oxygen, namely conjugated carbonyl and carboxylic groups. It was discovered that pressed Oltu-stone has nearly identical properties to standard Oltu-stone and could be produced on a large scale commercially.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 5; art. no. 169730
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zinc and graphene oxide composites as new protective coatings for oil and gas pipes
Kompozyty cynku i tlenku grafenu jako nowe powłoki ochronne rur do przesyłu nafty i gazu
Autorzy:
Asghar, M. Sajid Ali
Amir, Muhammad
Hussain, Umer
Sabri, Mohammed M.
Powiązania:
https://bibliotekanauki.pl/articles/24202808.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
corrosion resistance
graphene oxide
Hummers method
nanocomposites
electrophoretic deposition
odporność na korozję
tlenek grafenu
metoda Hummersa
nanokompozyty
osadzanie elektroforetyczne
Opis:
A method was developed to obtain a durable coating consisting of zinc and graphene oxide (Zn-GO) in order to reduce the mechanical wear and tear rate of oil and gas pipelines made of steel. Graphene oxide was obtained from graphite by wet chemical oxidation (unmodified and modified Hummers’ method) using potassium permanganate and sulfuric acid. The process was carried out at various temperatures. The steel was covered with an ultrathin layer of Zn-GO using the electrophoretic deposition method. The GO particle size (< 90 nm) was confirmed by XRD and laser analysis. For GO particles obtained by the modified Hummers’ method, a significant correlation was observed in the scratch (R2 = 0.87) and the Vickers microhardness tests (R2 = 0.93), which indicates a lower wear rate of Zn-GO-coated steel.
Opracowano metodę otrzymywania trwałej powłoki składającej się z cynku i tlenku grafenu (Zn-GO) w celu zmniejszenia zużycia mechanicznego rurociągów naftowo-gazowych wykonanych ze stali. Tlenek grafenu pozyskano z grafitu metodą mokrego utleniania chemicznego (niezmodyfikowana i zmodyfikowana metoda Hummersa) z użyciem nadmanganianu potasu i kwasu siarkowego. Proces prowadzono w różnej temperaturze. Stal powlekano ultra cienką warstwą Zn-GO techniką osadzania elektroforetycznego. Metodą XRD i analizą laserową potwierdzono wielkość cząstek GO (≤ 90 nm). Dla cząstek GO otrzymanych zmodyfikowaną metoda Hummersa zaobserwowano znaczącą korelację w teście zarysowania (R2 = 0.87) i mikrotwardości Vickersa (R2 = 0.93), co świadczy o mniejszym stopniu zużycia stali pokrytej powłoką Zn-GO.
Źródło:
Polimery; 2023, 68, 7-8; 378--385
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Does managerial coaching effect subordinates’ feedback orientation? Mediating role of affective supervisory commitment
Czy coaching kierowniczy wpływa na orientację opinii podległych pracowników? Mediacyjna i emocjonalna rola nadzoru
Autorzy:
Ali, Muhammad
Arbi, Khalil Ahmed
Raza, Basharat
Malik, Sania Zahra
Sheikh, Labiba
Powiązania:
https://bibliotekanauki.pl/articles/2021573.pdf
Data publikacji:
2020
Wydawca:
Politechnika Częstochowska
Tematy:
managerial coaching
affective supervisory commitment
subordinate feedback orientation
social exchange
coaching menedżerski
emocjonalne zaangażowanie w nadzór
orientacja na informacje zwrotne podwładnych
wymiana informacji
Opis:
Managerial coaching has become a widely used human resource development strategy to improve various employee outcomes within organizations. However, existing literature lacks empirical evidence regarding the effectiveness of managerial coaching and less known about how managerial coaching influences subordinate feedback orientation through the mediating effect of employees’ commitment to the supervisor. This study uses a structured questionnaire to gather data from a cross-sectional sample of 257 employees working in the banking sector of Lahore, Pakistan, with a response rate of approximately 57%. Structural Equation Modeling (SEM) is used to test the proposed hypotheses. The results reveal that managerial coaching has a positive and direct significant impact on the subordinate feedback orientation and affective supervisory commitment. Affective supervisory commitment has a positive and direct significant relationship with the subordinate feedback orientation. Affective supervisory commitment also mediates the indirect relationship between managerial coaching and subordinate feedback orientation. This research also provides implications for managers and leaders, specifically looking to improve various employee outcomes through managerial coaching in the workplace.
Coaching menedżerski stał się szeroko stosowaną strategią rozwoju zasobów ludzkich w celu poprawy wyników różnych pracowników w organizacjach. Jednak w istniejącej literaturze brakuje dowodów empirycznych dotyczących skuteczności coachingu menedżerskiego i mniej wiadomo na temat tego, jak coaching menedżerski wpływa na orientację zwrotną podwładnych poprzez mediacyjny efekt zaangażowania pracowników wobec przełożonego. W badaniu tym zastosowano ustrukturyzowany kwestionariusz w celu zebrania danych z przekrojowej próby 257 pracowników zatrudnionych w sektorze bankowym w Lahore w Pakistanie, przy wskaźniku odpowiedzi wynoszącym około 57%. Modelowanie równań strukturalnych (SEM) służy do testowania proponowanych hipotez. Wyniki pokazują, że coaching menedżerski ma pozytywny i bezpośredni znaczący wpływ na orientację zwrotną podwładnych i afektywne zaangażowanie przełożonych. Zaangażowanie w nadzór afektywny ma pozytywny i bezpośredni znaczący związek z podporządkowaną orientacją na informację zwrotną. Zaangażowanie w nadzór afektywny pośredniczy również w pośrednim związku między coachingiem menedżerskim a orientacją zwrotną podwładnych. Badania te dostarczają również implikacji dla menedżerów i liderów, w szczególności chcących poprawić wyniki różnych pracowników poprzez coaching menedżerski w miejscu pracy.
Źródło:
Polish Journal of Management Studies; 2020, 22, 2; 9-21
2081-7452
Pojawia się w:
Polish Journal of Management Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Equilibrium, kinetics and thermodynamic study of the adsorptive removal of methylene blue from industrial wastewater by white cedar sawdust
Autorzy:
Gardazi, Syed Mubashar H.
Shah, Jehanzeb Ali
Ashfaq, Tayyab
Sherazi, Tauqir A.
Ali, Muhammad Arif
Pervez, Arshid
Rashid, Naim
Iqbal, Javed
Amin, Bilal Ahmad Zafar
Bilal, Muhammad
Powiązania:
https://bibliotekanauki.pl/articles/207373.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
methylene blue
industrial wastewater
white cedar sawdust
WCS
dye adsorption
błękit metylenowy
ścieki przemysłowe
trociny białego cedru
adsorpcja barwników
Opis:
The study evaluated the adsorption potential of white cedar sawdust (WCS) for dye removal. WCS was chosen from five preferred, abundant waste biomasses from Pakistan. Various parameters such as contact time, adsorbent dose, dye concentration, pH, and particle size were optimized for methylene blue (MB) dye adsorption. The adsorbent was characterized by FTIR, SEM, EDX and BET analyses. The surface area of the adsorbent was 1.43 m2·g-1 and pore volume was 0.000687 cm3·g-1. The adsorption data best fitted the isotherm models of Langmuir, Temkin, Dubinin–Radushkevich, and Freundlich. The maximum experimental adsorption capacity obtained was 55.15 mg·g-1, which was in close agreement to the calculated adsorption capacity. Fitness of the pseudo-second order kinetics suggested chemisorption as the rate-limiting step. Thermodynamic study for adsorption was carried out to evaluate the Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°). The negative values ΔG° at the examined temperature range confirmed the spontaneous adsorption of MB onto WCS.
Źródło:
Environment Protection Engineering; 2019, 45, 3; 5-22
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Image encryption based on Chebyshev chaotic map and S8 S-boxes
Autorzy:
Hussain, Iqtadar
Anees, Amir
Alkhaldi, Ali Hussain
Aslam, Muhammad
Siddiqui, Nasir
Ahmed, Rehan
Powiązania:
https://bibliotekanauki.pl/articles/173918.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image encryption
chaos
noise-resistant
statistical analysis
key sensitivity
Opis:
The encryption of image data is artful as compare to others due to some special characteristics such as entropy, contrast, the correlation between the pixels, intensity, and homogeneity. During encryption process, it is conventionally not easy to manage these characteristics with non-chaotic cryptosystems. Therefore for the sake of strong encryption algorithms, in last decades many cryptographers have presented invulnerable schemes for image encryption based on the chaotic maps. This manuscript aims to propose a strong encryption scheme based on a symmetric group of permutation advanced encryption standard (AES) substitution boxes and modified Chebyshev map. Principally, the secret key depends upon the parameters of Chebyshev map to create confusion in the main image and is encrypted by the scheme made from the S8 AES S-boxes and chaotic map. By this procedure, one can obtain an encrypted image that is entirely twisted. The results of analyses showed that the presented image encryption is strong and invulnerable.
Źródło:
Optica Applicata; 2019, 49, 2; 317-330
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of steel fibres on fresh and hardened properties of cement concrete
Autorzy:
Ali, Saqib
Kumar, Haresh
Rizvi, Samar Hussain
Raza, Muhammad Saleem
Ansari, Jawaid Kamal
Powiązania:
https://bibliotekanauki.pl/articles/395745.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
cement concrete
steel fibres
compressive strength
tensile strength
workability
beton cementowy
włókna stalowe
wytrzymałość na ściskanie
wytrzymałość na rozciąganie
urabialność
Opis:
Concrete possesses distinct features that make it widely acceptable for use across the globe; however, along with its obvious benefits, it has numerous drawbacks i.e., it is brittle in nature and its production causes an adverse impact on the environment. To counter such problems, researchers around the world have introduced sustainable measures. Fibre addition is foremost among these solutions in that it prevents crack propagation and increases the overall strength of concrete. In the present age, civil engineering structures have their own structural and durability requirements and so, modification in traditional concrete has become a necessity. This research is targeted at steel fibre reinforced concrete (SFRC), which is a superior quality concrete because of its enhanced strength. The steel fibres are obtained from binding wire that is used to tie the steel reinforcement. By referring to past research, steel fibres with an aspect ratio (length to diameter ratio) of 30 were considered favourable. The controlled, mixed design of the concrete was prepared with a targeted strength of 4000 psi and, while mixing the concrete ingredients, fibres were added to allow uniform dispersion. The fresh and hardened properties of workability, compressive, and tensile strength were tested and the results of fibres at 0%, 1%, 2% and 3% concrete mass were compared and analysed. The results indicated that highest compressive and tensile strength values were achieved with 3% fibre addition. However, with further addition, it was observed that concrete loses its workability. Therefore, it is suggested that 1% addition of steel fibres produces good strength with sufficient workability.
Źródło:
Civil and Environmental Engineering Reports; 2020, 30, 3; 186-199
2080-5187
2450-8594
Pojawia się w:
Civil and Environmental Engineering Reports
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Fibre Orientation and Void Content in Bagasse Fibre Composites Using an Image Analysis Technique
Zastosowanie techniki analizy obrazu do badania orientacji włókien i zawartości pustych przestrzeni w kompozytach wzmocnionych włóknami bagasse
Autorzy:
Siddique, Sheraz Hussain
Faisal, Saira
Mohtashim, Qurat-ul-Ain
Ali, Muhammad
Gong, R. Hugh
Powiązania:
https://bibliotekanauki.pl/articles/1419413.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
composites
bagasse fibre
fibre orientation
void content
weight percentage
alkali treatment
kompozyty
włókno bagasse
orientacja włókien
zawartość wolnej przestrzeni
procent wagowy
obróbka alkaliczna
Opis:
In this research work, a nondestructive technique of image analysis was explored to determine the fibre orientation and void content in Bagasse fibre reinforced composites. Fibre length, alkali treatment and fibre loading were studied as variables. The fibre orientation was irrespective of the fibre length, fibre loading and alkali treatment variables. The void content and size decreased with increases in fibre length and alkali treatment. The alkali treatment resulted in the removal of lignin, making the surface of the fibres rough. It also led to making the fibre count fine i.e. reducing the diameter of the fibres and thus presenting more fibres for interaction with resin. Both these phenomena resulted in a slower flow of resin. The void content of bagasse fibre composites decreased with higher fibre loading because a higher number of fibres slows the resin flow. However, the size i.e. area of the voids increased with the fibre loading from 20 to 30%, probably due to increased wetting difficulty.
W pracy badawczej zbadano nieniszczącą technikę analizy obrazu w celu określenia orientacji włókien i zawartości pustych przestrzeni w kompozytach wzmocnionych włóknem bagasse. Jako zmienne zbadano długość włókien, obróbkę alkaliami i obciążenie włókien. Orientacja włókien była niezależna od długości włókna, obciążenia włókna i parametrów obróbki alkalicznej. Ilość i rozmiar pustych przestrzeni zmniejszały się wraz ze wzrostem długości włókna i obróbką alkaliczną. Obróbka alkaliczna spowodowała usunięcie ligniny, powodując szorstkość powierzchni włókien. Doprowadziło to również do dokładnego zliczenia włókien, tj. zmniejszenia średnicy włókien, a co za tym idzie większej liczby włókien w interakcji z żywicą. Oba te zjawiska spowodowały wolniejszy przepływ żywicy. Ilość pustych przestrzeni w kompozytach włókien bagasse zmniejszyła się wraz ze wzrostem obciążenia włókien, ponieważ większa liczba włókien spowalnia przepływ żywicy. Jednak rozmiar, tj. obszar pustych przestrzeni, wzrastał wraz z obciążeniem włókien od 20% do 30%, prawdopodobnie z powodu zwiększonej trudności zwilżania.
Źródło:
Fibres & Textiles in Eastern Europe; 2021, 3 (147); 26-32
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 40

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies