2,787 research outputs found

    An Overview of Challenges on Smallholder Agroforestry Farms in Jigawa State, Northern Nigeria

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    Under the threat from a cocktail of climate change, environmental and soil, degradation and present economic meltdown in the country and world over, the practice of agroforestry come under a myriad of challenges. This study looks at Jigawa state, which has an agrarian based economy. With an estimate of 0.8ha being the average size of farmlands in the state, this study attempts to outline the pressing challenges facing these smallholder farms. A multistage sampling was employed for the study. Using division of the state into 3 zones which include; Jigawa southwest, Jigawa northwest, Jigawa northeast and.  Out of each zone, 3LGA were selected out of which 50 respondents were purposively targeted from each community providing the study with sampling frame of 450 respondents. The analysis proceeded by using mean, percentages and use of table and figures. The results show that tenure insecurity, herder problems as challenges to the farmers. Laxity on part of the institutions adds to the list. The study recommends the revitalization of relevant bodies charged with maintenance and dissemination of information and incentives on use of modern agroforestry to ensure its sustainability. Keywords: Agroforestry, Smallholder, Tenure insecurity, Herder Proble

    PHOABE : securely outsourcing multi-authority attribute based encryption with policy hidden for cloud assisted IoT

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    Attribute based encryption (ABE) is an encrypted access control mechanism that ensures efficient data sharing among dynamic group of users. Nevertheless, this encryption technique presents two main drawbacks, namely high decryption cost and publicly shared access policies, thus leading to possible users’ privacy leakage. In this paper, we introduce PHOABE, a Policy-Hidden Outsourced ABE scheme. Our construction presents several advantages. First, it is a multi-attribute authority ABE scheme. Second, the expensive computations for the ABE decryption process is partially delegated to a Semi Trusted Cloud Server. Third, users’ privacy is protected thanks to a hidden access policy. Fourth, PHOABE is proven to be selectively secure, verifiable and policy privacy preserving under the random oracle model. Five, estimation of the processing overhead proves its feasibility in IoT constrained environments

    Constant-size threshold attribute based SignCryption for cloud applications

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    In this paper, we propose a novel constant-size threshold attribute-based signcryption scheme for securely sharing data through public clouds. Our proposal has several advantages. First, it provides flexible cryptographic access control, while preserving users’ privacy as the identifying information for satisfying the access control policy are not revealed. Second, the proposed scheme guarantees both data origin authentication and anonymity thanks to the novel use of attribute based signcryption mechanism, while ensuring the unlinkability between the different access sessions. Third, the proposed signcryption scheme has efficient computation cost and constant communication overhead whatever the number of involved attributes. Finally, our scheme satisfies strong security properties in the random oracle model, namely Indistinguishability against the Adaptive Chosen Ciphertext Attacks (IND-CCA2), Existential Unforgeability against Chosen Message Attacks (EUFCMA) and privacy preservation of the attributes involved in the signcryption process, based on the assumption that the augmented Multi-Sequence of Exponents Decisional Diffie-Hellman (aMSE-DDH) problem and the Computational Diffie Hellman Assumption (CDH) are hard

    PAbAC : a privacy preserving attribute based framework for fine grained access control in clouds

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    Several existing access control solutions mainly focus on preserving confidentiality of stored data from unauthorized access and the storage provider. Moreover, to keep sensitive user data confidential against untrusted servers, existing solutions usually apply cryptographic methods by disclosing data decryption keys only to authorized users. However, these solutions inevitably introduce a heavy computation overhead on the data owner for key distribution and data management when fine-grained data access control is desired. In addition, access control policies as well as users’ access patterns are also considered as sensitive information that should be protected from the cloud. In this paper, we propose PAbAC, a novel privacy preserving Attribute-based framework, that combines attribute-based encryption and attribute-based signature mechanisms for securely sharing outsourced data via the public cloud. Our proposal is multifold. First, it ensures fine-grained cryptographic access control enforced at the data owner’s side, while providing the desired expressiveness of the access control policies. Second, PAbAC preserves users’ privacy, while hiding any identifying information used to satisfy the access control. Third, PAbAC is proven to be highly scalable and efficient for sharing outsourced data in remote servers, at both the client and the cloud provider side

    pH Assist for Highly selective determination of Xipamide by the enhancement of the green emission of Tb3+ optical sensor

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    The highly selective, accurate method for determination of Xipamide was maintained. The method depends on the enhancement of the green emission band of Tb3+ at 545 nm in the presence of different concentration of  Xipamide at pH 4.1 and λex = 320 nm in acetonitrile. The photophysical properties of the green  emissive Tb3+  complex have been elucidated, the terbium was used as optical sensor for the assessment of  Xipamide in the pharmaceutical tablets and body fluids with a concentration range 5.0 ×10ñˆ’9 ñ€“ 2.3 ×10ñˆ’6 mol Lñˆ’1 of xipamide, correlation coefficient of 0.995 and  detection limit of 8.5 ×10ñˆ’10 mol Lñˆ’1

    An Assessment of Suitability of Climate for Tourism in Northwestern Nigeria

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    Tourism is vital to national economies and income of its individual citizens. This paper investigated the suitability of climate for tourism in Northwestern Nigeria using the tourism climate index developed by Mieczkowski (1985). Parameters used for calculating the index include monthly average maximum daily temperature, rainfall, mean daily relative humidity, minimum relative humidity, total wind speed and sunshine hours. The stations used for the calculation of TC index include Kaduna, Kano, Katsina and Sokoto. The result is presented in the form of charts using excel, while GIS is used for zoning of tourism climatic conditions in different months. Result shows that the study area is suitable for tourism throughout the year, as all the TCI scores ranges from 94 to 41 (‘ideal’ to ‘marginal') except for Kano in the month of June which has a TCI score of 39 (‘unfavorable’). The months of January, February, November and December are the best months for tourism as they recorded higher TCI values of 73 to 94 (‘very good’ to ‘ideal’). It is therefore concluded that the best time for tourist to visit Northwestern Nigeria is during the months of January, February, November and December. Keywords: Climate, Tourism, Tourism Climate Index, Nigeri

    Fuzzy Algorithm for Supervisory Voltage/Frequency Control of a Self Excited Induction Generator

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    This paper presents the application of a Fuzzy Logic Controller (FLC) to regulate the voltage of a Self Excited Induction Generator (SEIG) driven by Wind Energy Conversion Schemes (WECS). The proposed FLC is used to tune the integral gain (KI) of a Proportional plus Integral (PI) controller. Two types of controls, for the generator and for the wind turbine, using a FLC algorithm, are introduced in this paper. The voltage control is performed to adapt the terminal voltage via self excitation. The frequency control is conducted to adjust the stator frequency through tuning the pitch angle of the WECS blades. Both controllers utilize the Fuzzy technique to enhance the overall dynamic performance.  The simulation result depicts a better dynamic response for the system under study during the starting period, and the load variation. The percentage overshoot, rising time and oscillation are better with the fuzzy controller than with the PI controller type.

    Palm oil formulation as 34 % mayonnaise and evaluation of its biological efficacy against citrus mealybug, Planococcus citri under laboratory and field conditions

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    The use of environmentally friendly pesticides using palm oil derivatives as palm oil methyl ester (PME) carrier solvents has been reported. PME-based glyphosate isopropylamine nanoemulsion in the water against weeds has been the subject of numerous studies as well as palm oil methyl ester molluscicidal against golden apple snails. This study's major goal was to formulate palm oil in an appropriate formulation form and assess its insecticidal effectiveness against citrus mealybug, Planococcus citri. Palm oil was formulated as 34% oil in water emulsion (O/W) (mayonnaise). The new mayonnaise formulation successfully passed all physical and chemical testing requirements set out by pesticide organizations for (O/W) emulsions. Under laboratory conditions, it was biologically evaluated against nymphs and adults of the citrus mealybug, Planococcus citri, with serial concentrations. It had considerable insecticidal activity against all study stages, although the impact on nymphs was significantly greater than that on adults. This was evident from its LC50 values, which were 53.52 and 58.58 mg/ml for nymphs and adults, respectively. The citrus mealybug, Planococcus citri, in its adult, nymphs, and gravid stages, was tested using the new palm oil 34% mayonnaise formulation in the field. The highest mortality percentages were seen in the nymphs, followed by adults and then the gravid stage. After additional research, the newly developed palm oil formula might be employed to combat the citrus mealybug, Planococcus citri

    Evaluation of Propolis Gel in Two Different Polymeric Systems as an Adjunctive Aid to Non-Surgical Therapy in the Management of Stage III Grade B Periodontitis: A Randomized Clinical Trial

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    Background: The goal of this study was to clinically evaluate the effect of propolis gel in different polymeric systems as an adjunct to non-surgical therapy in the management of periodontitis patients. Methods: A total of 30 patients with stage III grade B periodontitis were divided into the following three groups: group I patients, who received propolis in a chitosan polymer gel with non-surgical therapy, group II patients, who received propolis in a polyox polymer gel with non-surgical therapy, and group III patients who served as a control treated with non-surgical therapy only. Clinical parameters were assessed at baseline, one month, and three months. Results: At three months, the mean gingival index (GI) of groups I and II was the same (0.6 ±0.52), and there was no change in the mean GI in group III. There was a reduction in the mean probing depth (PD) in group I (4.80 ±0.63) and group II (4.90 ±0.74) at the end of the study. The greatest percent gain in clinical attachment level (CAL) was noted in group II (17.26 ±6.71) followed by group I (5.93 ±9.87), whereas the least percent decrease was noted in group III (3.67 ±7.77). Conclusion: The adjunctive use of propolis in a polyox polymer with non-surgical therapy demonstrated superior clinical results over the use of propolis in a chitosan polymer in periodontitis patients
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