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Wyszukujesz frazę "Khan, S. A." wg kryterium: Autor


Tytuł:
Redesigning supply chain network of a lubricant company : an innovative approach
Reorganizacja łańcucha dostaw w przedsiębiorstwie branży olejowej : podejście innowacyjne
Autorzy:
Khan, S. A.
Sawicka, H.
Powiązania:
https://bibliotekanauki.pl/articles/361659.pdf
Data publikacji:
2016
Wydawca:
Wyższa Szkoła Logistyki
Tematy:
innovation
logistics
transportation
supply chain
lubricants
innowacja
logistyka
transport
łańcuch dostaw
branża olejowa
Opis:
Background: The purpose of this paper is to redesign the supply chain network of a lubricant company by implementing an innovative solution concentrated on the delivery of products and minimizing total loading, unloading and transportation costs. Methods: In this paper the authors' approach to redesigning the supply chain network (SCN) is presented. It comprises 3 phases: analysis of the current state of the SCN, identification of disadvantages in the SCN and SCN improvement. This step-wise procedure is verified on a real-world supply chain network, which is analyzed, evaluated and redesigned. Based on this analysis, the most important strengths and weaknesses are identified. The main criteria for evaluation are loading, unloading and transportation costs. A redesign of the company is proposed, the stakeholders' opinions are gathered and the innovative solution is implemented. Results: After successful implementation of the innovative solution, the result shows savings in loading, unloading and transportation costs and an improvement in the level of service. Research Limitations: The proposed methodology can be implemented in other supply chain networks. However, the way of limiting the loading, unloading and transportation costs presented in this paper cannot be regarded as a general rule applicable to all companies. Conclusions: This study presents innovative thinking in the logistics network of a company and the results obtained prove that companies which are innovative in terms of products can also become innovative in their services.
Wstęp: Celem niniejszego artykułu jest reorganizacja łańcucha dostaw firmy funkcjonującej w branży olejowej, poprzez wdrożenie innowacyjnego rozwiązania skoncentrowanego na dostawach produktów i poprzez minimalizację całkowitego załadunku, wyładunku towarów i kosztów transportu. Metody: W niniejszym artykule jest przedstawione podejście do reorganizacji łańcucha dostaw (ŁD). Składa się ono z 3 faz, tj. analizy stanu aktualnego ŁD, identyfikacji słabych stron ŁD oraz poprawy funkcjonowania ŁD. Przedstawiona wielofazowa procedura jest zweryfikowana na przykładzie rzeczywistego łańcucha dostaw, który jest poddany analizie, ocenie i reorganizacji. Na podstawie przeprowadzonej analizy, są definiowane jego najważniejsze mocne i słabe strony. Głównymi kryteriami oceny są koszty załadunku, wyładunku i transportu. Rekomendowana jest reorganizacja przedsiębiorstwa, zbierane są opinie osób zainteresowanych funkcjonowaniem łańcucha i zaimplementowane jest innowacyjne rozwiązanie. Wyniki: Po udanym wdrożeniu innowacyjnego rozwiązania, uzyskany rezultat pokazuje oszczędności w kosztach załadunku, wyładunku i transportu oraz poprawę poziomu świadczonych usług. Ograniczenia badawcze: Proponowana metodyka może być zastosowana w innych łańcuchach dostaw. Jednak przedstawiony sposób ograniczenia kosztów załadunku, wyładunku i transportu nie może być uznany, jako ogólna zasada dla wszystkich przedsiębiorstw. Ponadto badania nie uwzględniają sytuacji ewentualnych niedoborów magazynowych. Wnioski: Przedstawione wyniki badań koncentrują się na innowacyjnym podejściu do sieci logistycznej w wybranej firmie, a uzyskane wyniki dowodzą, że przedsiębiorstwo świadczące innowacyjne produkty, może stać się innowacyjne w sferze usług.
Źródło:
LogForum; 2016, 12, 2; 165-180
1734-459X
Pojawia się w:
LogForum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Overcoming Localization Errors due to Node Power Drooping in a Wireless Sensor Network
Autorzy:
Khan, S. A.
Daachi, B.
Djouani, K.
Powiązania:
https://bibliotekanauki.pl/articles/226280.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wireless sensor networks
RSSI
localization
range-free scheme
energy considerations
neural networks
Opis:
Received Signal Strength Indication (RSSI) plays a vital role in the range-free localization of sensor nodes in a wireless sensor network and a good amount of research has been made in this regard. One important factor is the battery voltage of the nodes (i.e., the MICAz sensors) which is not taken into account in the existing literature. As battery voltage level performs an indispensable role for the position estimation of sensor nodes through anchor nodes therefore, in this paper, we take into a account this crucial factor and propose an algorithm that overcomes the problem of decaying battery. We show the results, in terms of more precise localization of sensor nodes through simulation. This work is an extension to [1] and now we also use neural network to overcome the localization errors generated due to gradual battery voltage drooping.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 3; 341-346
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The relationship between green supply chain performance, energy demand, economic growth and environmental sustainability: an empirical evidence from developed countries
Relacja pomiędzy zielonym zarządzaniem łańcuchem dostaw, popytem na energię, wzrostem ekonomicznym i rozwojem zrównoważonym na podstawie krajów rozwiniętych
Autorzy:
Yu, Z.
Golpîra, H.
Khan, S. A. R.
Powiązania:
https://bibliotekanauki.pl/articles/361761.pdf
Data publikacji:
2018
Wydawca:
Wyższa Szkoła Logistyki
Tematy:
renewable energy
trade openness
greenhouse gas emissions
supply chain management
economic development
energia odnawialna
otwartość handlowa
emisja gazów cieplarnianych
zarządzanie łańcuchem dostaw
rozwój ekonomiczny
Opis:
Background: This study is for examining the association between green logistics, energy demand, renewable energy consumptions, environmental performance and sustainable economic development in a panel of nineteen developed economies around the globe over the period from 2008-2017. In addition, the article expands domain of green logistics from firm level to country level and also connects national scale economic indicators with green logistical performance. Methods: The study employs Pools OLS (ordinary least square) statistical technique to check hypothesis, while secondary data have been used, which were downloaded from the World Bank. Results: The results reveal that the green logistics indicators have strongly positive correlation with green energy sources, FDI inflows, and Trade openness. On the other hand, greenhouse gas emissions and carbon emissions have negative correlation with green logistics. Furthermore, renewable energy is a driving factor of green logistics and supply chain operations which also promote environmental and economic sustainability. Conclusion: This article provides the insight of the association between green logistics performance and national scale economic and environmental indicators. In addition, this research will help practitioners, senior managers and policymaker to understand the importance of renewable energy and green practices in logistical operations.
Wstęp: Praca prezentuje wyniki analizy powiązań pomiędzy zieloną logistyką, popytem na energię, konsumpcją energii odnawialnej, wpływem na środowisko oraz zrównoważonym rozwojem ekonomicznych na podstawie 19 rozwiniętych krajów z całego świata w okresie 2008-2017. Dodatkowo, omówiono rozwiniecie zielonej logistyki z poziomu przedsiębiorstwa do poziomu kraju jak również powiązano krajowe ekonomiczne wskaźniki z działalnością zielonej logistyki. Metody: Zastosowano metodę statystyczną Pools OLS dla sprawdzenia postawionych hipotez, gdzie użyto dane pochodzące z Banku Światowego. Rezultaty: Na podstawie otrzymanych wyników stwierdzono, że wskaźniki zielonej logistyki wykazują silną pozytywną korelację z zielonymi źródłami energii, przepływem FDI oraz otwartością handlu. Z drugiej strony emisja gazów cieplarnianych oraz węgla wykazuje negatywną korelację z zieloną logistyką. Dodatkowo, energia odnawialna jest wiodącym czynnikiem zielonej logistyki i operacji łańcucha dostaw, wspierającym również ekonomiczny rozwój zrównoważony. Wnioski: Praca przedstawia powiązania pomiędzy zieloną logistyką a krajowymi wskaźnikami ekonomicznymi i ekologicznymi. Dodatkowo, daje wskazówki dla praktyków, zarządzających średniego szczebla oraz politykom dla lepszego zrozumienia istotności energii odnawialnej oraz zielonych praktyk w operacjach logistycznych.
Źródło:
LogForum; 2018, 14, 4; 479-494
1734-459X
Pojawia się w:
LogForum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of base pressure behavior in a suddenly expanded duct at supersonic Mach number regimes using statistical analysis
Autorzy:
Quadros, J. D.
Khan, S. A.
Antony, A. J.
Powiązania:
https://bibliotekanauki.pl/articles/122311.pdf
Data publikacji:
2018
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
Mach number
Taguchi
nozzle pressure ratio
area ratio
liczba Macha
eksperyment Taguchi
model regresji liniowej
stosunek powierzchni
Opis:
The present experimental evaluation deals with the behavior of base pressure (BP) in a suddenly expanded duct at supersonic Mach number regimes. The experiments have been conducted for two cases viz. Without and with the use of microjets or active control. The plan of experiments was planned as per Taguchi design of experiments for acquiring data in a controlled manner. An L27 orthogonal array and analysis of variance (ANOVA) has been employed to investigate the contribution (in terms of percentage) of distinct process parameters like Mach number (M), Nozzle Pressure Ratio (N), Area Ratio (A) and their interactions affecting base pressure. The correlation between these parameters affecting base pressure has been obtained using multiple linear regression analysis. It has been concluded that the Mach number and area ratio were the factors that had high statistical significance on the behavior of base pressure for both cases. The performances of the developed linear regression models have been validated for accuracy prediction by use of 15 test cases. The performance of both the base pressure models was found to be better with percentage prediction in deviation lying in the range of –12.92% to +15.88% for base pressure without control and –10.27% to +19.23% for base pressure with control.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2018, 17, 4; 59-72
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Statistical Estimation and Mathematical Modelling of Tropospheric Radio Refractivity Based on Meteorological Data
Autorzy:
Alimgeer, K. S.
Awais, M.
Ijaz, B.
Khan, S. A.
Subhan, F.
Ahmad, N.
Powiązania:
https://bibliotekanauki.pl/articles/221069.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
radio refractivity
statistical estimation
ITU
mathematical modelling
Opis:
To obtain optimal performance, estimation of radio refractivity is essential in planning and design of radio links/systems. The dependence of radio refractivity on different climatic parameters such as temperature, pressure, humidity and scale height is studied. The method proposed by International Telecommunication Union (ITU) is used in calculation of tropospheric radio refractivity. The main objective of this work is to formulate a mathematical equation/expression which can be used to predict/estimate the value of radio refractivity for an arbitrary day of any year, with a low error of estimation, in a local environment. Sensitivity of radio refractivity to temperature, pressure and humidity has been evaluated for a period of 5 years from 2008 to 2012, in a particular area under consideration. The results presented for tropospheric radio refractivity take into consideration both the location height and scale height parameters. The results are analysed in terms of statistical measures such as the moving averages, probability density function, monthly mean values, and their corresponding standard deviations. Finally, a mathematical model is formulated to calculate the radio refractivity for any day of a whole year. Reliability of error analysis in respect to accuracy is also shown. It was implemented in the industrial enterprise.
Źródło:
Metrology and Measurement Systems; 2018, 25, 1; 115-128
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular epidemiology and phylogenetic analysis of Tams I gene of Theileria annulata in Khyber Pakhtunkhwa, Pakistan
Autorzy:
Shah, S.S.A.
Saddique, U.
Khan, M.A.
Khan, S.
Powiązania:
https://bibliotekanauki.pl/articles/16647390.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
crossbred cattle
Pakistan
PCR
risk factors
sequencing
theileriosis
Opis:
Theileriosis is a hemoparasitic disease that affects a wide range of different animal species and is caused by various species of Theileria. This study aimed to determine the molecular epidemiology of Theileria annulata through microscopy and PCR, in crossbred cattle in some districts of Khyber Pakhtunkhwa, Pakistan. For this study, a total of 384 blood samples were collected from cattle in the Peshawar (n=120), Charsadda (n=94), Nowshera (n=84), and Swabi (n=86) districts. Microscopy and PCR were used to determine the overall prevalence of theileriosis, which was found to be 15.8 and 22.6%, respectively. Theileria annulata was detected in blood samples through PCR in the study area, and the target gene i.e., Tams 1, of positive samples was sequenced. The sequences in the current study revealed high sequence homology (ranging from 96 to 100%) with Tams 1 sequences of neighboring countries present in the NCBI database. Season, breed, age, and sex were found to be important risk factors among the several risk factors examined, whereas, among different clinical manifestations, lymphadenopathy showed a strong association with theileriosis. According to Cohen’s kappa and ROC analysis, microscopy was proven to be a fair diagnostic test for detecting theileriosis in cattle, and may be used in combination with molecular techniques for screening a large number of animals.
Źródło:
Polish Journal of Veterinary Sciences; 2022, 25, 4; 625-629
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Classification of EEG Signals Using Adaptive Time-Frequency Distributions
Autorzy:
Khan, N. A.
Ali, S.
Powiązania:
https://bibliotekanauki.pl/articles/221878.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Adaptive Directional Time-Frequency Distribution
EEG signals
Time-Frequency features
pattern recognition
Opis:
Time-Frequency (t-f) distributions are frequently employed for analysis of new-born EEG signals because of their non-stationary characteristics. Most of the existing time-frequency distributions fail to concentrate energy for a multicomponent signal having multiple directions of energy distribution in the t-f domain. In order to analyse such signals, we propose an Adaptive Directional Time-Frequency Distribution (ADTFD). The ADTFD outperforms other adaptive kernel and fixed kernel TFDs in terms of its ability to achieve high resolution for EEG seizure signals. It is also shown that the ADTFD can be used to define new time-frequency features that can lead to better classification of EEG signals, e.g. the use of the ADTFD leads to 97.5% total accuracy, which is by 2% more than the results achieved by the other methods.
Źródło:
Metrology and Measurement Systems; 2016, 23, 2; 251-260
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of flood event in a reach of the Nile River using CCHE2D model
Autorzy:
Khan, A. A.
Wang, S. S. Y.
Powiązania:
https://bibliotekanauki.pl/articles/240958.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
river flow simulation
flood stage
stage-discharge relationship
Opis:
The impact of design flood in terms of water surface level and maximum velocity in a reach on the Nile River is studied, using a depth-averaged two-dimensional model. The reach includes a proposed site for a shipyard maintenance harbour. The CCHE2D model, a depth-averaged two-dimensional model, is selected to perform both the steady state computation, for calibration purposes, and flood routing through the reach to obtain maximum water surface level and velocity information. Manning's coefficient was obtained by matching the computed and measured water surface level in the reach under steady flow conditions. The computed results of velocity and water surface profiles agreed satisfactorily with the measured data. The verified model was then used to simulate a flood event within the same reach. Stage-discharge relationships for various sections within the reach were obtained. The peak water surface level at each section was compared with the flow stage under normal flow conditions. The peak stage was found to be well below the proposed elevation of the construction site. The estimation of the peak velocity and water surface level might be useful for bank protection work.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2003, 50, 4; 329-341
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Entropy generation on mhd flow of Powell-Eyring fluid between radially stretching rotating disk with diffusion-thermo and thermo-diffusion effects
Autorzy:
Khan, N. A.
Aziz, S.
Ullah, S.
Powiązania:
https://bibliotekanauki.pl/articles/386796.pdf
Data publikacji:
2017
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
axisymmetric flow
entropy generation
stretching disk
Powell-Eyring fluid
diffusion
Opis:
An investigation is performed for an alyzing the effect of entropy generation on the steady, laminar, axisymmetric flow of an incompressible Powell-Eyring fluid. The flow is considered in the presence of vertically applied magnetic field between radially stretching rotating disks. The Energy and concentration equation is taking into account to investigate the heat dissipation, Soret, Dufour and Joule heating effects. To describe the considered flow non-dimensionalized equations, an exact similarity function is used to reduce a set of the partial differential equation into a system of non-linear coupled ordinary differential equation with the associated boundary conditions. Using homotopy analysis method (HAM), an analytic solution for velocity, temperature and concentration profiles are obtained over the entire range of the imperative parameters. The velocity components, concentration and temperature field are used to determine the entropy generation. Plots illustrate important results on the effect of physical flow parameters. Results obtained by means of HAM are then compared with the results obtained by using optimized homotopy analysis method (OHAM). They are in very good agreement.
Źródło:
Acta Mechanica et Automatica; 2017, 11, 1; 20-32
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study on the Effect of Human Laterality, Type of Computer and Noise on Operators’ Performance of a Data Entry Task
Autorzy:
Khan, Z. A.
Rizvi, S. A. H.
Powiązania:
https://bibliotekanauki.pl/articles/90760.pdf
Data publikacji:
2009
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
equivalent noise level
motor-sidedness
visual display units
data entry task performance
Opis:
Effects of human laterality, type of computer and noise on computer operators’ performance of a data entry task were investigated. Seven right- and 7 left-motorsided male subjects performed the task on desktop and laptop computers in a sitting posture under varying noise levels. The mean number of characters entered per minute was statistically analysed. The right-motorsided operators entered more data than left-motorsided ones at each noise level. Operators performed better on desktop computers. Operators’ performance decreased when noise level increased from 82 to 92 dB(A) but it improved at 102 dB(A). Effects of laterality, type of computer and noise, and the interaction between laterality and noise were statistically significant. The interactions between laterality and type of computer, and type of computer and noise were statistically insignificant. Laterality was statistically significant at all noise levels and noise was statistically significant for right motor-sided operators only.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2009, 15, 1; 53-60
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Elimination of microbes from different drinking water sources of Visakhapatnam using potassium permanganate: dose based disinfection approach
Autorzy:
Dadhich, A.S.
Khan, H.R.
Powiązania:
https://bibliotekanauki.pl/articles/11840.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
elimination
microbe
drinking water
water source
Visakhapatnam area
potassium permanganate
disinfection
sanitation
microbial quality
Opis:
Potassium permaganate has been used since ages for disinfection of water. It is known for oxidation of cell membrane of micro organisms. But the pink colour prevailing after use makes people reject the water on aesthetic grounds. Water samples from bore wells and tap water from public places were collected from different areas of Visakhapatnam. Physio-chemical and microbial analysis analyses of the water samples were carried out. A dose based permaganate treatment of water depending upon number of colony forming units and species of microorganism present in the water was carried out [1,2,5].
Źródło:
International Letters of Natural Sciences; 2014, 11, 1
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-Step Martensitic Transformation in an Aged $Ti_{50}Ni_{15}Pd_{25}Cu_{10}$ High Temperature Shape Memory Alloys
Autorzy:
Rehman, S.
Khan, M.
Nusair Khan, A.
Ali, L.
Imran Jaffery, S.
Powiązania:
https://bibliotekanauki.pl/articles/1401938.pdf
Data publikacji:
2015-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.30.Kf
Opis:
Multi-step martensitic transformation in an aged Ni-rich binary NiTi shape memory alloy is considered as usual behavior during transformation from austenite to martensite phase; from (austenite) B2 to R-phase and then R-phase to B19' (monoclinic). However, for equi-atomic NiTi-based quaternary high temperature shape memory alloy, two-step martensitic transformation was detected for the first time. The $Ti_{50}Ni_{15}Pd_{25}Cu_{10}$ high temperature shape memory alloys were investigated for the evolution of transformation temperatures at aging temperature of 550°C and 700°C. Aging at 550°C for 6 h resulted in significant reduction of phase transformation temperatures. During forward transformation from austenite to martensite, two-step martensitic transformation B2 → R and R → B19 (orthorhombic) was observed. By aging the alloy at 700°C for 6 h, no significant effect was found on phase transition behavior and transformation temperatures.
Źródło:
Acta Physica Polonica A; 2015, 128, 2B; B-125-B-127
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study on the Effects of Human Age, Type of Computer and Noise on Operators’ Performance of a Data Entry Task
Autorzy:
Khan, Z. A.
Rizvi, S. A. H.
Powiązania:
https://bibliotekanauki.pl/articles/91125.pdf
Data publikacji:
2010
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
equivalent noise level
age
visual display units
data entry task performance
Opis:
The effects of human age, type of computer, and noise on computer operators’ performance of a data entry task were investigated. Twenty male subjects aged 10–55 were assigned into 4 age groups each consisting of 5 persons. They performed the task for 15 min on desktop and laptop computers in a sitting posture under varying levels of noise. The mean number of characters entered per minute (MNCEPM) was statistically analyzed. Operators in the 16–25 age group achieved the highest rate of data entry at each level of noise investigated. Operators performed better on desktop than on laptop computers. Their performance decreased when noise level increased from 82 to 92 dB(A), but it improved at 102 dB(A). The effects of age and noise were statistically significant. However, the effects of the type of computer, the interactions between age and type of computer, age and noise level, and type of computer and noise were not found to be statistically significant.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2010, 16, 4; 455-463
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the long-term variability of temperature trends and changes in surface air temperature in Kolkata Weather Observatory, West Bengal, India
Autorzy:
Khan, A.
Chatterjee, S.
Bisai, D.
Powiązania:
https://bibliotekanauki.pl/articles/108500.pdf
Data publikacji:
2015
Wydawca:
Instytut Meteorologii i Gospodarki Wodnej - Państwowy Instytut Badawczy
Tematy:
temperature
trend analysis
Mann-Kendall test
Sen’s slope estimator
Kolkata
Opis:
The impact of climate change on annual air temperature has received a great deal of attention from climatologists worldwide. Many studies have been conducted to illustrate that changes in temperature are becoming evident on a global scale. Air temperature, one of the most important components of climate parameters, has been widely measured as a starting point towards the apprehension of climate change and variability. The main objective of this study is to analyse the temporal variability of mean monthly temperature for the period of 1941 to 2010 (70 years). To detect the magnitude of trend in mean monthly temperature time series, we have used non-parametric test methods such as The Mann-Kendall test, often combined with the Theil-Sen’s robust estimate of linear trend. Whatever test is used, the user should understand the underlying assumptions of both the technique used to generate the estimates of a trend and the statistical methods used for testing. The results of this analysis reveal that four months – January, February, March and December – indicate a decreasing trend in average temperature, while the remaining eight months have an increasing trend. The magnitude of Mann-Kendall trend statistic Zc for this declining temperature and the magnitude of slope for the months of January, February and December are confirmed at the high significance levels of α = 0.001, 0.01 and 0.1 respectively. Though, the overall trend is positive for monthly as well as seasonally efficient time series.
Źródło:
Meteorology Hydrology and Water Management. Research and Operational Applications; 2015, 3, 2; 9-16
2299-3835
2353-5652
Pojawia się w:
Meteorology Hydrology and Water Management. Research and Operational Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel approach to enhance performance of multilayer coated carbide insert in hard turning
Nowe podejście do poprawy osiągów w toczeniu na twardo przy użyciu wielowarstwowej płytki z ceramiki narzędziowej
Autorzy:
Shihab, S. K.
Khan, Z. A.
Siddiquee, A. N.
Khan, N. Z.
Powiązania:
https://bibliotekanauki.pl/articles/140027.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hard turning
flank wear
Taguchi approach
multi-coated carbide
micro-channel
toczenie na twardo
zużycie krawędzi
podejście Taguchi
węglik wielowarstwowy
mikrokanał
Opis:
Flank wear of multilayer coated carbide (TiN/TiCN/Al2O3/TiN) insert in dry hard turning is studied. Machining under wet condition is also performed and flank wear is measured. A novel micro-channel is devised in the insert to deliver the cutting fluid directly at the tool-chip interface. Lower levels of cutting parameters yield the minimum flank wear which is significantly affected by cutting speed and feed rate. In comparison to dry and wet machining, insert with micro-channel reduces the flank wear by 48.87% and 3.04% respectively. The tool with micro-channel provides saving of about 87.5% in the consumption of volume of cutting fluid and energy.
W pracy przedstawiono badania nad zużyciem krawędzi skrawającej wielowarstwowej płytki z ceramiki narzędziowej (TiN/TiCN/Al2O3/TiN) w toczeniu twardym na sucho. Badano także zużycie krawędzi skrawającej w warunkach toczenia na mokro. Nowatorskim rozwiązaniem było zastosowanie mikrokanału w płytce skrawającej, przez który płyn smarny dostarczany jest bezpośrednio do styku między narzędziem i wiórem. Uzyskany tą drogą niższy poziom parametrów skrawania zapewnia minimalne zużycie krawędzi skrawającej, na które w istotny sposób wpływają prędkość skrawania i szybkość posuwu. W porównaniu do warunków toczenia na sucho i na mokro, zastosowanie mikrokanału zmniejsza zużycie krawędzi skrawającej o odpowiednio 48,87% i 3,04%. Narzędzie z mikrokanałem zapewnia także oszczędność zużycia płynu smarnego i energii o ok. 87,5%.
Źródło:
Archive of Mechanical Engineering; 2015, LXII, 4; 539-552
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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