733 research outputs found
Antecedents and Consequences of Global Supply Chain Process Integration
Global business executives and researchers recently highlight the importance of understanding the dynamics of supply chain process integration in a global context. The literature still lacks studies that provide a comprehensive understanding of the major antecedents and consequences of supply chain process integration from a global perspective. This dissertation builds on several theoretical foundations such as the resource based view (RBV), the relational view (RV) of the firm and transaction cost analysis (TCA) to develop a framework that explains the drivers and outcomes of global supply chain process integration.
This global study responds to these challenges through exploring the antecedents and consequences of global supply chain process integration for 320 supply chain and purchasing managers that source from over 33 countries. A theoretical framework is proposed that builds on research in strategic management, supply chain management, and international business and tests 8 proposed hypotheses. One new construct – global supply chain process integration – is developed and tested. Another construct, logistics performance, is modified from its existing form in the current literature.
Significant results and good fit indices tested with structural equation modeling generate a number of interesting implications for global supply chain managers and researchers. For executives and strategists who are concerned about better managing their supply chains, this study provides insights for how manufacturing firms can develop a competitive edge through a higher level of flexibility by integrating its supply chain processes with its global suppliers. The study also provides empirical evidence on how supplier flexibility in a global environment can lead to improvements in process and firm performance
A look into the past and future: theories within supply chain management, marketing and management
Purpose Although supply chain scholars have acknowledged the fundamental disruptive changes experienced by today\u2019s supply chains and the ensuing novelty of the research problems worthy of investigation, they have primarily relied on a limited number of theories to help explain the phenomena of interest. The purpose of this paper is to use a systematic literature review to address this gap and propose additional theories that supply chain researchers can use to help address novel supply chain phenomena, such as those caused by technological disruptions. Design/methodology/approach The authors use a systematic literature review to examine the studies published over the last 10 years in six of the top supply chain management journals (411 articles) and six of the top marketing and management journals (1,214 articles). Findings First, the findings show that 15 theories have been relied upon by over 95 per cent of the studies within supply chain management that use formal theories. Second, the authors identify the most frequently used theories within marketing and management (217 theories). Third, as space limitations make it impossible to offer a rich description of each of the 217 theories, the authors identify 30 theories that they considered to be the most salient to supply chain research and suggest areas where supply chain scholars can apply these theoretical lenses. Originality/value The research effort allowed the authors to map the current use of theories within the field to gain a better understanding of what other theories could augment the body of theories used within supply chain management. Thus, the current study is a \u201cone stop shop\u201d that supply chain scholars can consult when in a quandary about what theoretical lens to utilize
Equalization Architectures for High Speed ADC-Based Serial I/O Receivers
The growth in worldwide network traffic due to the rise of cloud computing and wireless video consumption has required servers and routers to support increased serial I/O data rates over legacy channels with significant frequency-dependent attenuation. For these high-loss channel applications, ADC-based high-speed links are being considered due to their ability to enable powerful digital signal processing (DSP) algorithms for equalization and symbol detection. Relative to mixed-signal equalizers, digital implementations offer robustness to process, voltage and temperature (PVT) variations, are easier to reconfigure, and can leverage CMOS technology scaling in a straight-forward manner. Despite these advantages, ADC-based receivers are generally more complex and have higher power consumption relative to mixed-signal receivers. The ensuing digital equalization can also consume a significant amount of power which is comparable to the ADC contribution. Novel techniques to reduce complexity and improve power efficiency, both for the ADC and the subsequent digital equalization, are necessary.
This dissertation presents efficient modeling and implementation approaches for ADC-based serial I/O receivers. A statistical modeling framework is developed, which is able to capture ADC related errors, including quantization noise, INL/DNL errors and time interleaving mismatch errors. A novel 10GS/s hybrid ADC-based receiver, which combines both embedded and digital equalization, is then presented. Leveraging a time-interleaved asynchronous successive approximation ADC architecture, a new structure for 3-tap embedded FFE inside the ADC with low power/area overhead is used. In addition, a dynamically-enabled digital 4-tap FFE + 3-tap DFE equalizer architecture is introduced, which uses reliable symbol detection to achieve remarkable savings in the digital equalization power. Measurement results over several FR4 channels verify the accuracy of the modeling approach and the effectiveness of the proposed receiver. The comparison of the fabricated prototype against state-of-the-art ADC-based receivers shows the ability of the proposed archi-tecture to compensate for the highest loss channel, while achieving the best power efficiency among other works
Sensitive spectrophotometric methods for determination of some organophosphorus pesticides in vegetable samples
Three rapid, simple, reproducible and sensitive spectrophotometric methods (A, B and C) are described for the determination of two organophosphorus pesticides, (malathion and dimethoate) in formulations and vegetable samples. The methods A and B involve the addition of an excess of Ce4+ into sulphuric acid medium and the determination of the unreacted oxidant by decreasing the red color of chromotrope 2R (C2R) at a suitable lmax = 528 nm for method A, or a decrease in the orange pink color of rhodamine 6G (Rh6G) at a suitable lmax = = 525 nm. The method C is based on the oxidation of malathion or dimethoate with the slight excess of N-bromosuccinimide (NBS) and the determination of unreacted oxidant by reacting it with amaranth dye (AM) in hydrochloric acid medium at a suitable lmax = 520 nm. A regression analysis of Beer-Lambert plots showed a good correlation in the concentration range of 0.1-4.2 μg mL−1. The apparent molar absorptivity, Sandell sensitivity, the detection and quantification limits were calculated. For more accurate analysis, Ringbom optimum concentration ranges are 0.25-4.0 μg mL−1. The developed methods were successfully applied to the determination of malathion, and dimethoate in their formulations and environmental vegetable samples
Utility of inorganic oxidants for the spectrophotometric determination of ganciclovir in dosage forms
Eight direct spectrophotometric methods for determination of ganciclovir has been developed and validated. These methods were based on the oxidation of the drug by different inorganic oxidants: ceric ammonium sulphate, potassium permanganate, ammonium molybdate, ammonium metavanadate, chromium trioxide, potassium dichromate, potassium iodate and potassium periodate. The oxidation reaction were performed in perchloric acid medium for ceric ammonium sulphate and in sulfuric acid medium for the other reagents. Different variables affecting the reaction conditions were carefully studied and optimized. Under the optimum conditions, linear relationships with good correlation coefficients (0.9987- 0.9993) were found between the reading and the corresponding concentration of the drug in the ranges of 2.0-1500 μg.mL–1 The limits of detection ranged from 0.26-18.25 μg mL–1 . The precision of the methods . was satisfactory; the values of relative standard deviations did not exceed 2.0 %. The proposed methods were successfully applied to the analysis of ganciclovir in dosage forms with good accuracy and precisions; the label claim percentages ranged from 99.9–100.4 ± 0.62–1.05 %.Colegio de Farmacéuticos de la Provincia de Buenos Aire
UTILITY OF CERTAIN σ AND π-ACCEPTORS FOR THE SPECTROPHOTOMETRIC DETERMINATION OF VORICONAZOL ANTIFUGAL DRUG IN PHARMACEUTICAL FORMULATION
Objective: Studies were carried out, for the first time, to investigate the charge-transfer reactions of voriconazole antifungal drug (VOR) as n-electron donor with the σ-acceptor iodine (I2) and various Ï€-acceptors: 7,7,8,8-tetracyanoquinodimethane (TCNQ); 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and p-chloranilic acid (p-CLA).Methods: The formation of the colored charge-transfer complexes were utilized in the development of simple, rapid and accurate spectrophotometric methods for the analysis of voriconazole in pure form as well as in its pharmaceutical formulation (tablets). Different variables affecting the reactions were studied and optimized.Results: Under the optimum reaction conditions, linear relationships with good correlation coefficients (0.9994–0.9999) were found between the absorbance and the concentration of voriconazole in the range of 2.0–120 μg mL−1. For more accurate analysis, Ringbom optimum concentration range was found to be between 4.0-110 μg mL-1. The limits of detection ranged from 0.36 to 1.23 μg mL−1andthe limits of quantification ranged from 1.20 to 4.10 μg mL−1. A Job's plot of the absorbance versus the molar ratio of voriconazole to each of acceptors under consideration indicated (1:1) ratio.Conclusion: The proposed methods were applied successfully for simultaneous determination of voriconazole in tablets with good accuracy and precision and without interferences from common additives. The results were compared favourably with the reported method.Â
DNA integrity in diagnosis of premalignant lesions
Carcinogenesis is a dynamic process which traditional biopsying can not keep up with. Saliva as fluid in the vicinity of the tumor can offer better insights to this process. This study aimed to identify the accuracy of salivary DNA integrity index in differentiating between oral premalignant lesions and oral cancer. This phase II diagnostic test accuracy study included 93 patients divided into three groups: 30 oral cancer patients, 33 patients with oral premalignant lesions divided into 21 oral lichen planus patients and 12 patients with leukoplakia and 30 normal individuals who acted as controls. Oral rinse was collected from all participants and they all underwent conventional visual and tactile examination, and patients with oral lesions had the diagnosis confirmed by histopathological examination of tissue biopsy. DNA integrity index was determined as the ratio between ALU247 and ALU115 measured by qPCR. There was no statistically significant difference regarding ALU115, ALU247 and DNA integrity index between the three study groups. The index was significantly higher in the oral cancer group than the oral lichen planus patients, while no significant difference was found between the oral cancer and the leukoplakia cases. The DNA integrity index sensitivity, specificity, positive and negative predictive values were 73%, 45%, 55% and 65% respectively. Salivary DNA integrity index showed poor diagnostic abilities in differentiating between the oral cancer and premalignant lesions
The submental flap for oral cavity reconstruction: Extended indications and technical refinements
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