350 research outputs found

    Enzymes used in detergents: Lipases

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    Microbial lipases are an important group of biotechnologically valuable enzymes, because of the versatility of their applied properties and ease of mass production. Lipases of microbial origin are widely diversified in their enzymatic properties and substrate specificity, which make them very attractive for industrial applications. This review describes the applications of microbial lipases in detergents. Enzymes can reduce the environmental load of detergent products as the chemicals used in conventional detergents are reduced; they are biodegradable, non-toxic and leave no harmful residues. Besides lipases, other enzymes are widely used in household cleaning products, in laundering, medical, agriculture, etc. This article also reviews the use of enzymes, especially lipases as detergents and different types of lipase containing detergents available in the market.Key words: Detergents, enzymes, lipases

    Adaptive receiver for visible light communication system

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    The future of visible light communication (VLC) systems relies on achieving moderate to high data rates and the ability to design a low complexity system, as these will play a major role in the next generation communication networks. In this paper, we propose, design, and evaluate the use of an adaptive receiver to mitigate the inter-symbol interference (ISI) and improve the overall VLC system performance while using a single element wide field of view (FOV) photodetector. In addition, we optimise the adaptive receiver by employing a different number of buffers to find the optimum configurations in terms of reducing the complexity and achieving the best performance. The proposed adaptive receiver is able to provide data rates of 1 Gbps with a BER of 10¯⁵ for OOK modulation in the worst case scenario

    Psychrotrophic bacteria isolated from -20°C freezer

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    Three psychrotrophic bacteria, morpho-physiologically, identified as Bacillus subtilis MRLBA7, Bacillus licheniformis MRLBA8 and Bacillus megaterium MRLBA9 were isolated from -20°C freezer of the Microbiology Research Laboratory (MRL), Quaid-i-Azam University, Islamabad, Pakistan. These strains were able to grow aerobically at 6°C but not at 40°C except MRLBA8 that could grow at 48°C. None of the isolates showed inhibition of growth in the presence of glycerol. Isolate MRLBA7, bearing central spore, grew in the presence of 30% glycerol at 0°C after 48 h of incubation and showed maximum growth without glycerol at 25°C after 24 h. Isolate MRLBA8 showed growth in the presence of 50% glycerol at 4°C after 72 h of incubation and maximum growth was observed at 20°C in the absence ofglycerol. Isolate MRLBA9 showed growth at 6°C in the presence of 40% glycerol after 48 h of incubation and maximum growth was observed at 25°C in the absence of glycerol. Isolates were susceptible to antibiotics except Bacillus subtilis MRLBA7 that exhibited antibiotic resistance against penicillin and fosphomycin, Bacillus licheniformis MRLBA8 against aztreonam and fosphomycin, and Bacillus megaterium MRLBA9 against vancomycin and penicillin. The growth profile and biochemical characteristics of all the isolates were rather similar to that of mesophilic counterparts except adaptation to low temperature. These strains could be used as model microbial strains for characterization of food contaminants in freezers, to understand the mechanism of antibiotic resistanceinduced at low temperature and as a source of psychrotrophic enzymes

    Consistent association of fungus Fusarium mangiferae Britz with mango malformation disease in Pakistan

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    Mango malformation disease (MMD) deforms the natural shape of panicles and shoots. The disease incitant is of great concern due to its complexity and mode of infection. Recently, a new species Fusarium mangiferae Britz was confirmed as the etiological agent of MMD in African and Asian clade. There was a need to confirm the fungus in other Asian countries. We investigated the association of F. mangiferae with malformed branches of five exotic and five indigenous cultivars of Mangifera indica L. in Pakistan. F. mangiferae proved to be the dominant fungus hosting majority of the malformed tissues. Among the indigenous cultivars, maximum tissue infection of 96.66% was found in cultivar Anwar Rataul and minimum was found in cultivar Late Chaunsa (48.33%). In exotic ones, maximum and minimum infections of 97.33 and 70.67% were noted in the cultivars Sensation and Pop, respectively. Light and transmission electron microscopy proved helpful in investigating the morphological matrix and ultrastructure of the propagules of fungus F. mangiferae.Key words: Mangifera indica, microconidium, Pakistan, tissue assay, transmission electron microscopy

    VLC Systems with CGHs

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    The achievable data rate in indoor wireless systems that employ visible light communication (VLC) can be limited by multipath propagation. Here, we use computer generated holograms (CGHs) in VLC system design to improve the achievable system data rate. The CGHs are utilized to produce a fixed broad beam from the light source, selecting the light source that offers the best performance. The CGHs direct this beam to a specific zone on the room's communication floor where the receiver is located. This reduces the effect of diffuse reflections. Consequently, decreasing the intersymbol interference (ISI) and enabling the VLC indoor channel to support higher data rates. We consider two settings to examine our propose VLC system and consider lighting constraints. We evaluate the performance in idealistic and realistic room setting in a diffuse environment with up to second order reflections and also under mobility. The results show that using the CGHs enhances the 3 dB bandwidth of the VLC channel and improves the received optical power

    LiDAL: Light Detection and Localization

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    In this paper, we present the first indoor light-based detection and localization system that builds on concepts from radio detection and ranging (radar) making use of the expected growth in the use and adoption of visible light communication (VLC), which can provide the infrastructure for our Light Detection and Localization (LiDAL) system. Our system enables active detection, counting, and localization of people, in addition to being fully compatible with the existing VLC systems. In order to detect human (targets), LiDAL uses the visible light spectrum. It sends pulses using a VLC transmitter and analyses the reflected signal collected by a photodetector receiver. Although we examine the use of the visible spectrum here, LiDAL can be used in the infrared spectrum and other parts of the light spectrum. We introduce LiDAL with different transmitter-receiver configurations and optimum and sub-optimum detectors considering the fluctuation of the received reflected signal from the target in the presence of Gaussian noise. We design an efficient multiple input multiple output (MIMO) LiDAL system with a wide field of view (FOV) single photodetector receiver, and also design a multiple input single output (MISO) LiDAL system with an imaging receiver to eliminate the ambiguity in target detection and localization. We develop models for the human body and its reflections and consider the impact of the color and texture of the cloth used as well as the impact of target mobility. A number of detection and localization methods are developed for our LiDAL system, including cross correlation and a background subtraction method. These methods are considered to distinguish a mobile target from the ambient reflections due to background obstacles (furniture) in a realistic indoor environment

    Artificial Neural Network for LiDAL Systems

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    In this paper, we introduce an intelligent light detection and localization (LiDAL) system that uses artificial neural networks (ANN). The LiDAL systems of interest are MIMO LiDAL and MISO IMG LiDAL systems. A trained ANN with the LiDAL system of interest is used to distinguish a human (target) from the background obstacles (furniture) in a realistic indoor environment. In the LiDAL systems, the received reflected signals in the time domain have different patterns corresponding to the number of targets and their locations in an indoor environment. The indoor environment with background obstacles (furniture) appears as a set of patterns in the time domain when the transmitted optical signals are reflected from objects in LiDAL systems. Hence, a trained neural network that has the ability to classify and recognize the received signal patterns can distinguish the targets from the background obstacles in a realistic environment, especially given the mobility of targets (humans) which distinguishes them from static obstacles (furniture). The LiDAL systems with ANN are evaluated in a realistic indoor environment through computer simulation

    Parallel Data Transmission in Indoor Visible Light Communication Systems

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    This paper presents an indoor visible light communication (VLC) system in conjunction with an imaging receiver with parallel data transmission (spatial multiplexing) to reduce the effects of the inter-symbol interference (ISI). To distinguish between light units (transmitters) and to match the light units used to convey the data with the pixels of the imaging receiver, we propose the use of subcarrier multiplexing (SCM) tones. Each light unit transmission is multiplexed with a unique tone. At the receiver, a SCM tone decision system is utilized to measure the power level of each SCM tone and consequently associate each pixel with a light unit. In addition, the level of co-channel interference (CCI) between light units is estimated using the SCM tones. Our proposed system is examined in two indoor environments taking into account reflective components (first and second order reflections). The results show that this system has the potential to achieve an aggregate data rate of 8 Gb/s with a bit error rate of 10 –6 for each light unit, using simple on-off-keying (OOK)

    An innovative decision-making framework for supplier selection based on a hybrid interval-valued neutrosophic soft expert set

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    The best way to achieve sustainable construction is to choose materials with a smaller environmental impact. In this regard, specialists and architects are advised to take these factors into account from the very beginning of the design process. This study offers a framework for selecting the optimal sustainable building material. The core goal of this article is to depict a novel structure of a neutrosophic soft expert set hybrid called an interval-valued neutrosophic soft expert set for utilization in construction supply chain management to select a suitable supplier for a construction project. This study applies two different techniques. One is an algorithmic technique, and the other is set-theoretic. The first one is applied for the structural characterization of an interval-valued neutrosophic expert set with its necessary operators like union and OR operations. The second one is applied for the construction of a decision-making system with the help of pre-described operators. The main purpose of the algorithm is to be used in supply chain management to select a suitable supplier for construction. This paper proposes a new model based on interval-valued, soft expert and neutrosophic settings. In addition to considering these settings jointly, this model is more flexible and reliable than existing ones because it overcomes the obstacles of existing studies on neutrosophic soft set-like models by considering interval-valued conditions, soft expert settings and neutrosophic settings. In addition, an example is presented to demonstrate how the decision support system would be implemented in practice. In the end, analysis, along with benefits, comparisons among existing studies and flexibility, show the efficacy of the proposed structure

    Feasibility and acceptability of home-based management of malaria strategy adapted to Sudan's conditions using artemisinin-based combination therapy and rapid diagnostic test

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    <p>Abstract</p> <p>Background</p> <p>Malaria remains a major public health problem especially in sub-Saharan Africa. Despite the efforts exerted to provide effective anti-malarial drugs, still some communities suffer from getting access to these services due to many barriers. This research aimed to assess the feasibility and acceptability of home-based management of malaria (HMM) strategy using artemisinin-based combination therapy (ACT) for treatment and rapid diagnostic test (RDT) for diagnosis.</p> <p>Methods</p> <p>This is a study conducted in 20 villages in Um Adara area, South Kordofan state, Sudan. Two-thirds (66%) of the study community were seeking treatment from heath facilities, which were more than 5 km far from their villages with marked inaccessibility during rainy season. Volunteers (one per village) were trained on using RDTs for diagnosis and artesunate plus sulphadoxine-pyrimethamine for treating malaria patients, as well as referral of severe and non-malaria cases. A system for supply and monitoring was established based on the rural health centre, which acted as a link between the volunteers and the health system. Advocacy for the policy was done through different tools. Volunteers worked on non-monetary incentives but only a consultation fee of One Sudanese Pound (equivalent to US$0.5).</p> <p>Pre- and post-intervention assessment was done using household survey, focus group discussion with the community leaders, structured interview with the volunteers, and records and reports analysis.</p> <p>Results and discussion</p> <p>The overall adherence of volunteers to the project protocol in treating and referring cases was accepted that was only one of the 20 volunteers did not comply with the study guidelines. Although the use of RDTs seemed to have improved the level of accuracy and trust in the diagnosis, 30% of volunteers did not rely on the negative RDT results when treating fever cases. Almost all (94.7%) the volunteers felt that they were satisfied with the spiritual outcome of their new tasks. As well, volunteers have initiated advocacy campaigns supported by their village health committees which were found to have a positive role to play in the project that proved their acceptability of the HMM design. The planned system for supply was found to be effective. The project was found to improve the accessibility to ACTs from 25% to 64.7% and the treatment seeking behaviour from 83.3% to 100% before- and after the HMM implementation respectivly.</p> <p>Conclusion</p> <p>The evaluation of the project identified the feasibility of the planned model in Sudan's condition. Moreover, the communities as well as the volunteers found to be satisfied with and supportive to the system and the outcome. The problem of treating other febrile cases when diagnosis is not malaria and other non-fever cases needs to be addressed as well.</p
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