An improved damage detection index for a structural component is proposed, using eigenvalues estimated by means of frequency domain decomposition (FDD) and mode contribution subjected to ambient excitation. It is based on vibration measurements obtained from the acceleration data of a simple steel beam. Since the extraction of modal parameters involves practical limitations and, in general, it is difficult to obtain accurate results, therefore in the proposed method a derivative value of the time series acceleration response, termed modal contributing parameter (MCP), is used in combination with eigenfrequencies. The damage is indicated by element stiffness reduction (ESR). Different damage cases for various stiffness reduction values of 1% to 15% were investigated. Damage identification indices for every single damage and multiple damage cases were calculated. The modified MCP damage detection index showed a high index value, even for low-level damage with an element stiffness reduction of as low as 1% over the existing frequency drop and indices based on mode shape change. MCP index derived from the modal response, considering modal contributions to the entire structural response and eigenvalues for damage detection, improved overall sensitivity and reliability of index results. Both single and multiple cases of damage provided equally accurate results based on the MCP index value.
Desulfurization of Pakistani coal has been carried out through alkaline leaching. During present experimental investigation, the effect of operating parameters like alkali concentration, time, temperature and particle size has also been analyzed, graphically represented and critically discussed. Parametric optimization of leaching process has been carried out by using response surface methodology (RSM) based on central composite design (CCD). The analysis of variance (ANOVA) was performed in order to assess the highest level interactions of variables and three way interactions were observed significant. Further, the optimum value of total sulfur removal was observed as 53% when the operatic conditions fixed at 10% W/V, 60 min, 80°C and 140 mesh for alkaline concentration, leaching time, temperature and particle size, respectively.
The current study focused on the use of textile industry waste (cotton and jute) and glass fabric for the development of hybrid composites. Composites were fabricated using either a single reinforcement or different fractions of cotton, jute and glass fabric. A good fibre-matrix interface was observed using Scanning Electronic Microscopy (SEM). The mechanical performance of the composites developed was analysed under certain loads. The tensile and flexural properties of the composites developed from waste material was found lower as compared to the glass fiber composites, while hybrid composites had comparable properties. Regression equations were also developed to predict the mechanical properties of the hybrid composites. Dynamic Mechanical Analysis (DMA) results revealed that after some pre-treatment (mercerization and desizing) textile waste materials can be used with virgin material in the reinforcement part of the composite to decrease the cost, but with optimum mechanical properties.
PL
Przeprowadzone badania koncentrowały się na wykorzystaniu odpadów włókienniczych (bawełna i juta) oraz wyrobów z włókien szklanych do rozwoju kompozytów hybrydowych. Otrzymane kompozyty poddano ocenie przy użyciu skaningowej mikroskopii elektronowej (SEM), a także zbadano ich właściwości mechaniczne. Wytrzymałość na rozciąganie i zginanie kompozytów wytworzonych z materiału odpadowego były niższe w porównaniu z kompozytami z włókna szklanego, podczas gdy kompozyty hybrydowe miały porównywalne właściwości. W celu przewidywania właściwości mechanicznych kompozytów hybrydowych opracowano równania regresji. Wyniki dynamicznej analizy mechanicznej (DMA) wykazały, że po pewnym wstępnym przygotowaniu (merceryzacja i usuwanie klejonki) odpady włókiennicze mogą być z powodzeniem stosowane w połączeniu z nieużywanym materiałem w części wzmacniającej kompozytu, przyczyniając się do zmniejszenia kosztów produkcji, przy zachowaniu optymalnych właściwości mechanicznych kompozytów. Wytwarzanie kompozytów hybrydowych może śmiało przyczynić się do rozwiązania problemów związanych z usuwaniem odpadów tekstylnych.
Typical textile waste water contains a high concentration of spent dye that can pose serious destructive impact on aquatic environment. Therefore, treatment of textile industry effluents is strictly imposed by the relevant government authorities and environmental protection agencies. During present studies, spent dye was removed using potato starch, an environmental friendly, biodegradable and cost effective coagulant, through coagulation/flocculation process. Analysis of variance (ANOVA) was performed that indicated the interaction of process parameters. It was observed that the interaction of temperature, pH and coagulant dosage were the most significant parameters that can affect the coagulation/flocculation process. So, temperature, pH and coagulant dosage were optimized by Taguchi optimization technique. The results indicated that maximum dye (about 27%) was removed when temperature, pH and coagulant dosage were kept at 55°C, 10 and 0.5% (w/v), respectively.
The assemblage of textiles and electronics in a single structure has led to the development of smart textiles for functional purposes and special products. Conductive yarn as a necessary component of smart textiles is being developed by a number of techniques. The objective of the current study was to impart conductivity to yarn by coating the silver and copper nanoparticles on the surface of multifilament polyester textile fibres. The surface morphology and electrical conductivity of the coated yarns were investigated. The wash ability of the conductive yarns developed was also studied. The yarns showed good retention of the nanoparticles, as proven by the very small loss of the conductivity of the material.
PL
Połączenie tekstyliów i elektroniki w jednej strukturze doprowadziło do rozwoju inteligentnych tekstyliów znajdujących zastosowanie w celach funkcjonalnych i produktach specjalnych. Przędza przewodząca, jako niezbędny składnik inteligentnych wyrobów włókienniczych, może być otrzymywana za pomocą szeregu różnych technik. Celem badania było nadanie przewodnictwa przędzy poliestrowej poprzez powlekanie jej nanocząsteczkami srebra i miedzi. Zbadano morfologię powierzchni i przewodnictwo elektryczne powleczonych przędz, a także ich odporność na pranie. Przędze wykazywały dobrą retencję nanocząstek, co potwierdzała bardzo mała utrata przewodności materiału.
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The aim of this study was to analyse the effects of various fabric parameters on the thermal resistance, thermal conductivity, thermal transmittance, thermal absorptivity and thermal insulation of polyester/cotton double layer knitted interlock fabrics. It was found that by increasing fibre content with higher specific heat increases the thermal insulation while decreases the thermal transmittance and absorptivity of the fabric. It was concluded that double layer knitted fabrics developed with higher specific heat fibres, coarser yarn linear densities, higher knitting loop length and fabric thickness could be adequately used for winter clothing purposes.
Use of bran oil in various edible and nonedible industries is very common. In this research work, efficient and optimized methodology for the recovery of rice bran oil has been investigated. The present statistical study includes parametric optimization, based on experimental results of rice bran oil extraction. In this study, three solvents, acetone, ethanol and solvent mixture (SM) [acetone: ethanol (1:1 v/v)] were employed in extraction investigations. Response surface methodology (RSM), an optimization technique, was exploited for this purpose. A five level central composite design (CCD) consisting four operating parameter, like temperature, stirring rate, solvent-bran ratio and contact time were examined to optimize rice bran oil extraction. Experimental results showed that oil recovery can be enhanced from 71% to 82% when temperature, solvent-bran ratio, stirring rate and contact time were kept at 55°C, 6:1, 180 rpm and 45 minutes, respectively while fixing the pH of the mixture at 7.1.
In this study, corncob was used as reductant for sulfuric acid leaching of manganese ore from Daweezi, Upper Mohmand Agency, Pakistan. X-ray diffraction of representative powdered samples revealed the presence of manganese silicate MnSiO(SiO4), calcite (CaCO3), and -quartz (SiO2). X-ray diffraction and energy dispersive spectroscopy analyses indicated that the examined manganese ore was siliceous in nature. Three process parameters were investigated in the present study including the particle size of the ore, leaching temperature, and amount of corncob. Manganese extraction of 92.48 wt% was achieved for a leaching time of 60 min at 90 oC using 1.9 mol/dm3 H2SO4 concentration and 4 g of corncob. The present results demonstrated that corncob is a low cost, renewable, and non-hazardous reducing agent for manganese leaching under mild acid conditions in comparison to the other available reagents.
A study of magnetohydrodynamic (MHD) flow with viscous dissipation and heat transfer in an electrically conducting laminar steady viscous incompressible micropolar fluid between two infinite uniformly stretching disks is presented. The transformed self similar nonlinear ODEs are first linearized using a quasi linearization method and then solved by employing a combination of a direct and an iterative method. The study may be beneficial to flow and thermal control of polymeric processing.
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The alternative system of medicines like Unani and Ayurveda is preferred worldwide nowadays due to its therapeutic efficacy, lower side effects, holistic approach, psychological dimensions, and qualitative action of weather and seasonal requirement. A simple procedure is described for the simultaneous extraction and estimation of piperlongumine and piperine in a well-known Unani polyherbal formulation using reversed-phase high-performance liquid chromatography (HPLC). The chromatography was carried out on reversed-phase C18 (250 × 4.6 mm) column with a mobile phase containing acetonitrile—water (50:50 v/v). Detection was accomplished with ultraviolet (UV) detection at λ = 325 nm. The flow rate was kept as 1.0 mL−1. The proposed method was validated according to International Conference on Harmonization (ICH) guidelines for accuracy (94.4–105.0%), precision (0.37–2.17% RSD), and robustness (0.14–2.11% RSD). The limit of detection (LOD) values were found as 30 and 10 ng mL−1, while limit of quantification (LOQ) was 100 and 30 ng mL−1 for piperlongumine and piperine, respectively, which proved the sensitivity of the method satisfactory enough for accurate analysis of the both piperlongumine and piperine.
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This paper aims to investigate the relationship between fabric weave structure and its comfort properties. The two basic weave structures and four derivatives for each selected weave structure were studied. Comfort properties, porosity, air permeability and thermal resistance of all the fabric samples were determined. In our research the 1/1 plain weave structure showed the highest thermal resistance making it suitable for cold climatic conditions. The 2/2 matt weave depicted the lowest thermal resistance which makes it appropriate for hot climatic conditions.
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A common problem faced in fabric manufacturing is the production of inconsistent fabric width on shuttleless looms in spite of the same fabric specifications. Weft-wise crimp controls the fabric width and it depends on a number of factors, including warp tension, temple type, fabric take-up pressing tension and loom working width. The aim of this study is to investigate the effect of these parameters on the fabric width produced. Taguchi’s orthogonal design was used to optimise the weaving parameters for obtaining controlled fabric width. On the basis of signal to noise ratios, it could be concluded that controlled fabric width could be produced using medium temple type and intense take-up pressing tension at relatively lower warp tension and smaller loom working width. The analysis of variance revealed that temple needle size was the most significant factor affecting the fabric width, followed by loom working width and warp tension, whereas take-up pressing tension was least significant of all the factors investigated in the study.
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High-performance thin-layer chromatography (HPTLC) method for the quantification of eugenol from nanostructured drug delivery systems was successfully developed and validated. The mobile phase consisted of n-hexane:acetone (7:3, v/v), and the densitometric scanning was performed in the absorbance mode at 280 nm. The method was valid with respect to linearity and range, accuracy, precision, specificity, detection limit (DL), and quantitation limit (QL). The linearity of the method was established by a correlation coefficient value of 0.9930 ± 0.0013. The precision was tested by checking intra-day (repeatability) and inter-day (intermediate precision) variations. The method was established to be precise by low relative standard deviation (RSD) values for different concentration of eugenol. The results of the recovery studies of eugenol from preanalyzed samples demonstrated the accuracy of the method. The specificity of the developed method for the analysis of eugenol in the nanoemulsion gel and nanoparticles samples was confirmed by comparing the spectra obtained in standard and sample analysis. The DL and QL were determined to be 31.41 and 95.17 ng band−1, respectively, for the HPTLC method. The forced degradation studies revealed on eugenol established the effectiveness of the developed and validated method. The developed and validated HPTLC method was found to be a stability-indicating one, as indicated by the results of forced degradation studies, for its use during the accelerated stability studies of the nanoemulsion gels and nanoparticles of eugenol.
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Andrographolide and betulinic acid are the terpenoids having potential anti-cancer activity. The cytotoxicity activity of both the drugs was carried out separately and in combination on liver cancer HepG2 cell lines. High-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) methods were developed and validated for simultaneous estimation of these two terpenoids as per the International Conference on Harmonization (ICH) guidelines, which was applied for quantification in nanoformulation. The retention time by HPLC and retardation factor by HPTLC for andrographolide and betulinic acid were found to be 2.2 and 6.6 min, and 0.24 ± 0.01 and 0.66 ± 0.01, respectively. Both the methods were validated for accuracy, precision, repeatability, robustness, limit of detection (LOD), and limit of quantitation (LOQ). The content of andrographolide and betulinic acid in nanoformulation was found to be 96.0% and 98.0% by HPLC and 96.59% and 98.33% by HPTLC, respectively, of labelled claim.
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The stability of a general Linear Time-Invariant (LTI) Ultra-WideBand (UWB) Channel Impulse Response (CIR) model is investigated. Since the s-domain or z-domain function of the UWB CIR has an extremely high number of singularities, it cannot be automatically guaranteed that none of the poles falls on the right-half of the s-plane or outside the unit-circle of the z-plane. Hence the stability analysis necessitates the exhaustive testing of classical stability criterion for a potentially excessive number of poles. We circumvent this arduous task by developing the closed-form time-domain response of the so-called homogenous, non-homogenous and vectorial LTI causal UWB system. Furthermore, the normalized settling time of the step response is evaluated for diverse damping coefficients. Finally, a stability case-study is provided with the aid of Nichols chart.
PL
Zbadano stabilność ultra szerokopasmowego kanału LTI. Ponieważ na płaszczyźnie s i z odpowiedź impulsowa ma wiele osobliwości nie można automatycznie zagwarantować, że wszystkie są w prawe połówce płaszczyzny s lub wewnątrz koła jednostkowego z. W pracy zaproponowano metodę określania stabilności kanału.
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Channel Equalization plays an important role in reducing distortion and Inter-Symbol Interference (ISI) to improve the quality of transmission in Ultra-Wide Band (UWB) channel. Many equalization techniques have been proposed in the past but the proposed techniques in this paper describes Infinite Impulse Response (IIR) equalizer architecture which halves the memory requirement of conventional IIR equalizers. This is achieved by exploiting the aperiodically repeated clusters of negative-exponentially decaying segments of Channel Impulse Response (CIR) and hence by providing a single delay- line between the input and output of the equalizer. Further this architecture is realized by implementing on Application Specific Integrated Circuit (ASIC) using Mentor Graphics IC Design tools. Mathematical modeling gives suitable parameters of the IIR Filter, followed by Register Transfer Level (RTL) Design using Very High Descriptive Language (VHDL), ASIC synthesis to TSMC 0.35um process technology, physical modeling using advanced layout techniques. The IIR equalization filter is designed using 8758 Metal Oxide Semi-conductor (MOS) transistors with core cell area of 0.406mm2.
PL
W artykule zaproponowano architekturę ekwalizera NOI, która zmniejsza wymagania pamięci przy transmisji szerokopasmowej w układach ASIC. Zaprezentowano układ w technologii 35 nm z tranzystorami MOS przy powierzchni celki jądra 0.406 mm2.
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A new simple, accurate, selective, precise, economical and stability-indicating high-performance thin layer chromatographic method for the analysis of diosgenin in callus and rhizome of Dioscorea deltoidea was developed and validated. The method was developed on TLC aluminium plates precoated with silica gel 60F254 using solvent system petroleum ether-isopropanol (12:1, v/v), which gives a compact spot of diosgenin (RF value 0.76 ± 0.02). Densitometric analysis of diosgenin was carried out in the absorbance mode at 366 nm after spraying with methanolic sulphuric acid. The linear regression analysis data for the calibration plots showed good linear relationship with r2 = 0.991 and 0.995 for diosgenin with respect to peak height and peak area, respectively, in the concentration range of 100–1000 ng per spot. The limits of detection and quantification for diosgenin were 16.58 and 50.25 ng per spot. The proposed method was applied for determination of diosgenin in rhizome of D. deltoidea (0.047% w/w) as well as in in vitro culture (callus) (0.092% w/w). Statistical analysis proves that the method is repeatable, selective and accurate for the estimation of diosgenin in D. deltoidea. The developed method effectively resolved the diosgenin in D. deltoidea; hence, it can be employed for routine analysis as a stability indicating method.
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In this chapter, an isocratic reverse phase HPLC determination of mimosine was developed and validated in an anti-psoriatic topically applied formulation “Lajjalu”. The chromatography was performed on a C18 column with water-orthophosphoric acid (98.8:0.2, υ/υ) as a mobile phase with a pH of 3.0 at a flow rate of 1.0 mL min-1. Detection was performed at 284 nm, and a sharp peak was obtained for mimosine at a retention time of 2.62 ± 0.01 min. Linear regression analysis data for the calibration plot showed a good linear relationship between response curve and concentration in the range of 0.050–5000 ng mL-1 and the regression coefficient was 0.9998 with the linear regression equation y = 4766.8x−17726. The detection (LOD) and quantification (LOQ) limits were 10.3 and 35.6 ng mL-1, respectively. The wide linearity range, sensitivity, accuracy, short retention time, and simple mobile phase imply the method is suitable for routine quantification of mimosine with high precision and accuracy.
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A validated reversed-phase HPLC method has been developed for quantitative analysis of berberine in Berberis aristata fruits and in a polyherbal formulation. Separation of berberine was achieved on a C18 column with a mobile phase consisting of a 10–80% acetonitrile gradient in 0.05% aqueous orthophosphoric acid. The flow rate was 1 mL min-1. Detection was at 266 nm. A sharp, well defined peak was obtained at a retention time of 10.0 ± 0.4 min. The method was validated in accordance with ICH guidelines for accuracy, precision, robustness, and the limits of detection (LOD) and quantification (LOQ). Results from linear regression analysis were indicative of a good linear relationship (r2 = 0.998 ± 0.0011) in a wide concentration range (5–500 μ g mL-1). LOD and LOQ were 1.5 and 5.3 μg mL-1, respectively. Satisfactory recovery results (94.6–103.1%) were obtained by the method of standard addition. Intra-day, inter-day, and intersystem precision was satisfactory, with relative standard deviation in the range 0.7–1.8%. The berberine content of fruit of Berberis aristata and the herbal formulation were 0.033% and 0.0089% (w/w), respectively. This HPLC method for quantification of berberine can be used for quality control and standardization of several crude drugs and different herbal formulations in which berberine is present as a phyto constituent.
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A sensitive, selective, precise and stability-indicating high-performance thin layer chroma-tographic (HPTLC) method for analysis of donepezil hydrochloride (DH) as bulk drug and in formulations was developed and validated. TLC aluminum plates pre-coated with 60 F-254 silica gel (20 x 10 cm) were used as the stationary phase. The solvent system consisted of butanol-water-glacial acetic acid (5:4:1, v/v/v). Densitometric analysis of DH was carried out in the absorbance mode at 260 nm. This system was found to give compact spots for DH (RF= 0.53 š 0.03 for six replicates). DH was subjected to acidic and alkaline hydrolysis, oxidation, dry and wet heat treatment, and photodegradation; under all these conditions the drug underwent degradation. Degradation products had significantly different RF values and thus were well separated from the pure drug. The method was validated with respect to linearity, precision, robustness, limit of detection (LOD), limit of quantification (LOQ), ruggedness and accuracy. Linearity was observed in the range 50—1000 ng per spot with a significantly high value of the correlation coefficient r2 = 0.9979; 95% confidence interval of r2 was 0.9908-0.9995. The mean S.E. value of the slope was 0.1316 with respect to the peak area. LOD and LOQ were 15.40 and 50.90 ng per spot, respectively. Statistical analysis proved that the method was repeatable and specific for the estimation of the studied drug. As the method could effectively separate the drug from its degradation products, it can be employed as a stability-indicating procedure.
PL
Opracowano i zwalidowano czułą, selektywną i precyzyjną, metody wysokosprawnej TLC do analizy chlorku donezepilu (DH) jako substancji chemicznej i w preparatach. Metoda umożliwia również ocenę trwałości leku. Zastosowano płytki na podłożu aluminiowym o wymiarach 20 * l O cm, pokryte żelem krzemionkowym 60 F-254. Jako eluent zastosowano butanol-wodę-lodowaty kwas octowy (5:4:1, v/v/v). DH wykrywano densytometrycznie przy 260 nm. W tych warunkach otrzymano zwarte plamki DH z RF= 0,53 š 0,03 dla sześciu powtórzeń. DH poddawano hydrolizie kwasowej i zasadowej, utlenianiu, ogrzewaniu na mokro i na sucho oraz naświetlaniu. We wszystkich tych przypadkach lek ulegał degradacji. Produkty degradacji miały wyraźnie różne wartości RFi były dobrze oddzielone od wyjściowego leku. Metodę walidowano uwzględniając liniowość, precyzje, odporność, wykrywalność, oznaczalność i dokładność. Liniowość obserwowano w zakresie 50—1000 ng w plamce, ze współczynnikiem korelacji r2 = 0,9979. Średnia wartość nachylenia wynosiła 0,1316 w odniesieniu do powierzchni piku. Wykrywalność i oznaczalność wynosiła odpowiednio 15,40 i 50,90 ng w plamce. Za pomocą analizy statystycznej wykazano, że metoda oznaczania badanego związku jest powtarzalna i specyficzna, umożliwia też oddzielanie leku od produktów jego degradacji, dzięki czemu może być zastosowana do badania trwałości leku.
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